Eurycoma longifolia
Longjack
Malaysian Ginseng
Pasak Bumi
Tung Saw
LJ100

---
canonical_name: Tongkat Ali
alternate_names: Eurycoma longifolia, Longjack, Malaysian Ginseng, Pasak Bumi, Tung Saw, LJ100
canonical_topic: Tongkat Ali to Improve Testosterone
short_topic_lc: tongkat_ali_testosterone
creation_date: 2026-0619-0317
creator_ai_fullname: Opus 4.8
ep_keywords: Adaptogens
---

# Tongkat Ali to Improve Testosterone

Evidence Review created on 06/19/2026 using [AI4L](https://github.com/forever-healthy/AI4L) / Opus 4.8

**Also known as:** Eurycoma longifolia, Longjack, Malaysian Ginseng, Pasak Bumi, Tung Saw, LJ100

## Motivation

Tongkat Ali (*Eurycoma longifolia*), a flowering shrub native to Southeast Asia, is a root extract long used in traditional medicine and now widely sold as a supplement marketed to raise testosterone, boost energy, and improve sexual function. Its root contains a group of bitter compounds, most notably eurycomanone, thought to act on the body's hormone-regulating signals rather than adding hormones directly. This distinction is central to why it draws interest from people seeking to support their own hormone production.

Testosterone tends to decline gradually with age, and many adults look for ways to maintain it without resorting to prescription hormone therapy. Tongkat Ali has been studied for several decades in Malaysia and beyond, with small trials reporting improvements in testosterone, mood, and stress markers, particularly in older men or those under physical or psychological stress.

This review examines what the evidence shows about Tongkat Ali's effect on testosterone and related outcomes, the quality of that evidence, the proposed mechanisms, the potential risks, and the practical considerations involved in its use.

**[Benefits](#expected-benefits) - [Risks](#potential-risks--side-effects) - [Protocol](#therapeutic-protocol) - [Conclusion](#conclusion)**

## Recommended Reading

This section lists high-quality, high-level overviews of Tongkat Ali from independent experts and publications that discuss the supplement and its effects in substantial depth.

* [How To Increase Your Testosterone Levels Naturally – Derek from MPMD](https://www.foundmyfitness.com/episodes/more-plates-more-dates) - Rhonda Patrick

  In this FoundMyFitness episode, Rhonda Patrick and Derek (More Plates More Dates) directly weigh whether Tongkat Ali is the best herbal testosterone booster and how it compares to alternatives such as boron, offering an evidence-minded, practical perspective for the proactive user.

* [Developing a Rational Approach to Supplementation for Health & Performance](https://www.hubermanlab.com/episode/developing-a-rational-approach-to-supplementation-for-health-and-performance) - Andrew Huberman

  Andrew Huberman discusses Tongkat Ali by name as one of the few supplements with human data suggesting modest support for testosterone, framing it within a broader, mechanism-focused discussion of supplementation for the proactive listener.

* [Review on a Traditional Herbal Medicine, Eurycoma longifolia Jack (Tongkat Ali): Its Traditional Uses, Chemistry, Evidence-Based Pharmacology and Toxicology](https://pubmed.ncbi.nlm.nih.gov/26978330/) - Rehman et al., 2016

  This narrative review compiles the phytochemistry and pharmacology of *Eurycoma longifolia*, detailing the quassinoid compounds responsible for its proposed hormonal and anti-stress effects and offering useful mechanistic context.

* [Effect of Tongkat Ali on stress hormones and psychological mood state in moderately stressed subjects](https://pubmed.ncbi.nlm.nih.gov/23705671/) - Talbott et al., 2013

  This frequently cited human trial reports that Tongkat Ali supplementation lowered cortisol and raised testosterone while improving tension, anger, and confusion scores in moderately stressed adults, anchoring the supplement's best-supported stress-resilience signal. Note the conflict of interest: its lead author is affiliated with a commercial supplement company (SupplementWatch), a tie that recurs across much of the Tongkat Ali evidence base and warrants cautious interpretation.

*Note: Four items are listed rather than five. No directly relevant, in-depth content dedicated to Tongkat Ali was found from Peter Attia or Chris Kresser; their available material does not cover the supplement by name in substantial depth. The list was not padded with reference-database, encyclopedia, or marginally relevant entries to reach five.*

## Grokipedia

[Tongkat Ali](https://grokipedia.com/page/Tongkat_ali) - Grokipedia

The Grokipedia entry provides a broad, continuously updated overview of *Eurycoma longifolia*, covering its botany, traditional use, phytochemistry, and the current state of the testosterone and fertility evidence, serving as a convenient orientation to the topic.

## Examine

[Tongkat Ali](https://examine.com/supplements/eurycoma-longifolia-jack/) - Examine

Examine's dedicated page is the most comprehensive independent, evidence-graded resource on Tongkat Ali, systematically rating each claimed effect (testosterone, libido, body composition, stress) against the underlying human trials.

## ConsumerLab

[Sexual Enhancer Supplements Review](https://www.consumerlab.com/reviews/enhancement-supplements-yohimbe-goat-weed-arginine/enhancement/) - ConsumerLab

ConsumerLab's review evaluates the evidence and tests products containing sexual-enhancement and testosterone-support ingredients including Tongkat Ali (Long Jack), making it useful for judging product quality, label accuracy, and which ingredients have supporting evidence.

## Systematic Reviews

This section lists systematic reviews and meta-analyses indexed on PubMed that evaluate Tongkat Ali's effects on testosterone and related outcomes.

* [Eurycoma longifolia (Jack) Improves Serum Total Testosterone in Men: A Systematic Review and Meta-Analysis of Clinical Trials](https://pubmed.ncbi.nlm.nih.gov/36013514/) - Leisegang et al., 2022

  This meta-analysis of randomized clinical trials reports a statistically significant increase in total testosterone with *Eurycoma longifolia* supplementation, with the effect confirmed in the hypogonadal (low-testosterone) subgroup, while cautioning that more research is needed before clinical use.

* [Eurycoma Longifolia as a potential adoptogen of male sexual health: a systematic review on clinical studies](https://pubmed.ncbi.nlm.nih.gov/28259255/) - Thu et al., 2017

  This review synthesizes human clinical studies on Tongkat Ali for male sexual health and hormonal parameters, finding that most trials show benefit for erectile dysfunction, libido, and testosterone, though several failed to demonstrate sufficient effects.

* [Efficacy of Tongkat Ali (Eurycoma longifolia) on erectile function improvement: systematic review and meta-analysis of randomized controlled trials](https://pubmed.ncbi.nlm.nih.gov/26365449/) - Kotirum et al., 2015

  This meta-analysis of randomized trials finds that Tongkat Ali may improve erectile function, with a significant effect seen only in men with lower baseline function, underscoring the baseline-dependent nature of the response.

* [An evidence-based systematic review of tongkat ali (Eurycoma longifolia) by the Natural Standard Research Collaboration](https://pubmed.ncbi.nlm.nih.gov/23419023/) - Ulbricht et al., 2013

  This evidence-based review consolidates the safety and efficacy data using a validated grading rationale, compiling clinical trials, pharmacology, interactions, adverse effects, and dosing into a single reference graded for evidence quality.

* [A systematic review and evidence-based analysis of ingredients in popular male testosterone and erectile dysfunction supplements](https://pubmed.ncbi.nlm.nih.gov/32358510/) - Kuchakulla et al., 2021

  This review grades the trial evidence behind common testosterone- and erectile-dysfunction-supplement ingredients, identifying *Eurycoma longifolia* among the most frequently used while noting that most ingredients have limited or contradictory randomized-trial support.

## Mechanism of Action

Tongkat Ali's effects are attributed mainly to a class of bitter compounds called quassinoids, the most studied of which is eurycomanone, along with eurypeptides (short protein fragments) and other root constituents.

The leading proposed mechanism is that Tongkat Ali supports the body's own testosterone production rather than supplying hormone directly. Several pathways are described:

* **Hypothalamic-pituitary-gonadal (HPG) axis signaling:** The HPG axis is the hormonal feedback loop linking the brain (hypothalamus and pituitary gland) to the testes. Eurycomanone is proposed to increase the release of luteinizing hormone (LH, the pituitary signal that tells the testes to make testosterone), thereby stimulating endogenous (the body's own) testosterone synthesis.

* **Aromatase and SHBG effects:** Eurycomanone is reported in laboratory studies to inhibit aromatase (the enzyme that converts testosterone into estrogen) and to lower sex hormone-binding globulin (SHBG, a blood protein that binds testosterone and makes it unavailable to tissues). Both effects would raise the amount of free, biologically active testosterone.

* **Anti-stress / cortisol pathway:** Tongkat Ali is described as an adaptogen (a substance proposed to help the body resist stress). By reducing cortisol (the primary stress hormone), it may improve the testosterone-to-cortisol ratio, which is relevant because high cortisol suppresses testosterone.

* **Antioxidant protection of Leydig cells:** The compounds may protect Leydig cells (the testosterone-producing cells in the testes) from oxidative damage, supporting steroidogenesis (hormone manufacture).

Competing mechanistic interpretations exist. Critics note that much of the aromatase-inhibition and LH-stimulation data come from animal and cell-culture work at concentrations that may not be achieved in humans at typical doses, and that the human testosterone signal is more reliably seen in men who start with low or stress-suppressed levels. Supporters counter that the consistent cortisol-lowering effect provides a plausible indirect route to testosterone preservation even when direct steroidogenic effects are modest.

Tongkat Ali is a botanical extract rather than a single defined drug, so classical pharmacological parameters are not precisely characterized. Eurycomanone, the marker compound, has been reported to have relatively low oral bioavailability with an estimated elimination half-life on the order of 1–5 hours in animal models; metabolism and tissue distribution in humans are not well defined, and standardized extracts are dosed to a fixed eurycomanone or eurypeptide percentage rather than to plasma levels.

## Historical Context & Evolution

* **Original use:** Tongkat Ali was originally used in the traditional medicine systems of Malaysia, Indonesia, and surrounding regions, where a root decoction (boiled extract) was taken as a general tonic, an aphrodisiac, and a remedy for fatigue, fever, and malaria. The name "Tongkat Ali" translates roughly as "Ali's walking stick," a folk reference to its reputed virility-enhancing properties.

* **Transition to health optimization:** Interest in Tongkat Ali for hormone optimization grew from the late 1990s onward, when Malaysian government-funded research institutes and universities began isolating and standardizing the root's active compounds. The development of patented, water-soluble standardized extracts (notably LJ100, standardized to eurycomanone and eurypeptides) shifted the supplement from a crude botanical to a quantified product, enabling the small clinical trials that drive current interest among proactive, longevity-oriented users.

* **Findings of early research:** Early Malaysian studies described increases in testosterone, improvements in sperm quality, gains in muscle strength, and reductions in fatigue. A frequently cited 2013 study in physically active older adults reported increased free and total testosterone alongside reduced cortisol after several weeks of supplementation.

* **Standing of the historical research:** Some of the early Malaysian work has been criticized for small sample sizes, ties to extract manufacturers, and inconsistent standardization, and a portion of the literature involves authors with commercial interests in specific extracts. Rather than being dismissed outright, these findings should be read as suggestive but preliminary; later independent systematic reviews have partly supported a testosterone signal in low-baseline populations while questioning its size and generalizability to young, healthy men.

* **Evolution of scientific opinion:** Opinion has shifted from initial enthusiasm toward a more qualified position: the cortisol-lowering and stress-resilience effects appear relatively robust, while the magnitude of direct testosterone elevation remains contested. New meta-analytic evidence has both strengthened the case for a statistically detectable testosterone increase and underscored how much depends on baseline status, extract standardization, and trial quality. The current picture is not settled, and well-powered independent trials are still needed.

## Expected Benefits

A dedicated search across PubMed, systematic reviews, Examine, and expert commentary was performed to compile the complete benefit profile before writing this section. Benefits are framed for risk-aware adults actively seeking to optimize hormonal health, for whom baseline status and effort tolerance matter more than population averages.

### Medium 🟩 🟩

#### Cortisol Reduction & Stress Resilience

Tongkat Ali's most consistently reported effect is a reduction in the stress hormone cortisol, with an accompanying improvement in subjective stress, tension, and mood. The proposed mechanism is adaptogenic modulation of the stress-response axis. The evidence basis includes a moderate-stress cohort trial (whose lead author is affiliated with a commercial supplement company, a conflict of interest common to this literature) reporting roughly a 16% reduction in cortisol and improved tension and confusion scores, plus supportive findings in several small randomized trials. For the proactive user managing high training or life stress, this stress-buffering effect — and its indirect support of the testosterone-to-cortisol ratio — may be the most dependable benefit.

**Magnitude:** Approximately 10–16% reduction in salivary cortisol versus baseline or placebo in stressed cohorts.

#### Testosterone Increase in Low-Baseline or Older Men

In men with low baseline testosterone, late-onset hypogonadism, or age-related decline, Tongkat Ali has been reported to raise total and free testosterone toward the normal range. The proposed mechanism combines HPG-axis stimulation, reduced SHBG, and lowered cortisol. The evidence basis includes a meta-analysis of randomized trials showing a statistically significant testosterone increase and an open-label study in hypogonadal men reporting normalization of testosterone in a majority of participants. The signal is most relevant to older, risk-aware adults seeking to preserve hormonal status, and is weaker or absent in young eugonadal men.

**Magnitude:** Total testosterone increases of roughly 10–15% over baseline in low-T or older cohorts; one open-label study reported normalization in ~90% of hypogonadal men.

### Low 🟩

#### Improved Male Fertility & Sperm Quality

Tongkat Ali has shown improvements in sperm concentration, motility, and morphology in men with idiopathic infertility, attributed to antioxidant protection of sperm and Leydig cells plus modest hormonal support. The evidence basis is several small open-label and controlled studies in subfertile men, without large independent replication. For adults pursuing fertility optimization, this is a plausible but under-powered benefit.

**Magnitude:** Reported sperm concentration and motility improvements of roughly 40–60% over baseline in small subfertile cohorts.

#### Libido & Sexual Well-Being

Improvements in libido, erectile satisfaction, and overall sexual well-being have been reported, consistent with the supplement's traditional aphrodisiac reputation and partly mediated by testosterone and stress effects. The evidence basis is small randomized and observational studies using validated sexual-function questionnaires, with effects most evident in men with low baseline function. Effect sizes are modest and confounded by mood and stress improvements.

**Magnitude:** Modest improvements (single-digit to low-double-digit point gains) on validated sexual well-being and erectile-function questionnaires.

#### Muscle Strength & Body Composition

Some trials report small gains in muscle strength, fat-free mass, or reductions in fat when Tongkat Ali is combined with resistance training, plausibly via testosterone and cortisol effects. The evidence basis is a few small exercise-training studies with mixed results and short durations. For training-focused users, any ergogenic effect appears small and secondary to the training stimulus itself.

**Magnitude:** Not quantified in available studies.

### Speculative 🟨

#### General Energy, Vitality & Well-Being

Beyond measurable hormones, users and traditional use describe increased energy, reduced fatigue, and improved overall vitality. No controlled studies isolate this as a primary endpoint; the basis is mechanistic (cortisol and testosterone effects) and anecdotal, and it overlaps substantially with the stress and mood findings rather than representing an independent, validated benefit.

#### Bone & Metabolic Health Support ⚠ Conflicted

Animal data and a few preliminary human signals suggest Tongkat Ali might support bone density and certain metabolic markers via androgen-mediated pathways. Evidence is directly conflicted: some animal studies show benefit while human data are sparse and inconsistent, and androgenic effects could theoretically cut either way depending on dose and population. This remains mechanistic and anecdotal, with no controlled human outcomes establishing benefit.

## Benefit-Modifying Factors

* **Baseline testosterone status:** The single largest modifier. Men with low or stress-suppressed baseline testosterone show the clearest gains, while young, eugonadal men with normal levels typically see little or no testosterone change.

* **Genetic polymorphisms:** Variation in the androgen receptor (the protein testosterone acts through) CAG-repeat length and in *CYP19A1* (the gene encoding aromatase, the enzyme converting testosterone to estrogen) may influence how strongly a given testosterone change translates into clinical benefit, though no pharmacogenetic testing is validated for Tongkat Ali specifically.

* **Sex-based differences:** Most evidence is in men. Limited data in women (e.g., for libido and well-being) exist, but hormonal effects, dosing, and the benefit profile differ and are far less characterized; benefits described here are male-centric.

* **Pre-existing health conditions:** Underlying conditions that suppress testosterone (chronic stress, obesity, metabolic syndrome, subfertility) tend to predict greater apparent benefit, since there is more deficit to correct.

* **Age-related considerations:** Older adults at the upper end of the target range, who experience natural testosterone decline and higher cortisol, are among the most likely to see meaningful hormonal and stress benefits.

* **Extract standardization:** Benefit depends heavily on a properly standardized extract (e.g., to a defined eurycomanone percentage); under-dosed or adulterated products may show no effect regardless of individual factors.

## Potential Risks & Side Effects

A dedicated search across drug-reference and clinical sources (Examine, published trial safety data, case reports, and toxicology literature) was performed to compile the complete side-effect profile before writing this section. Tongkat Ali is generally well tolerated in trials, but quality and contamination issues create real-world risks for the proactive user.

### Medium 🟥 🟥

#### Heavy-Metal Contamination of Products

Independent testing has repeatedly found mercury, lead, arsenic, or cadmium in some commercial Tongkat Ali products, reflecting soil uptake by the root and poor manufacturing controls rather than the compound itself. The mechanism of harm is chronic heavy-metal toxicity (neurological, renal, and developmental). The evidence basis includes contamination surveys and independent product-testing reports. For a supplement often taken long-term, this is arguably the most clinically relevant risk and is largely avoidable through verified, tested products.

**Magnitude:** Contamination detected in a meaningful minority of tested products; some samples exceeded safety limits for mercury or lead by several-fold.

### Low 🟥

#### Insomnia, Restlessness & Overstimulation

Some users report difficulty sleeping, restlessness, irritability, or a "wired" feeling, plausibly related to its stimulating and pro-androgenic effects. The evidence basis is trial-reported adverse events and consistent user reports rather than controlled characterization. Effects are generally mild, dose-related, and reversible on discontinuation or dose reduction; taking it earlier in the day mitigates sleep disruption.

**Magnitude:** Reported by a small percentage of users in trials and surveys; typically resolves within days of stopping.

#### Gastrointestinal Upset & Mild Symptoms

Nausea, stomach discomfort, headache, and the root's intense bitterness can cause mild gastrointestinal complaints. The mechanism is direct gastrointestinal irritation. The evidence basis is adverse events recorded in clinical trials, where rates were low and comparable to placebo. These effects are mild, transient, and often reduced by taking the supplement with food.

**Magnitude:** Low incidence in trials, generally similar to placebo.

#### Hormonal Overstimulation & Mood Changes ⚠ Conflicted

Because Tongkat Ali can raise androgenic activity, theoretical risks include aggression, anxiety, acne, or in susceptible men effects on the prostate. Evidence is directly conflicted: some users and mechanistic reasoning suggest androgen-related effects, while controlled trials have not shown consistent adverse hormonal events or prostate changes at standard doses. The discrepancy likely reflects individual sensitivity, dose, and product variability, and the signal remains unconfirmed in rigorous data.

**Magnitude:** Not quantified in available studies.

### Speculative 🟨

#### Liver Enzyme Elevation

Isolated concern exists that botanical supplements, including Tongkat Ali at high or adulterated doses, could affect liver enzymes. No controlled human trial has established hepatotoxicity at standard doses; the basis is general supplement-safety caution and rare, often confounded case reports (frequently involving multi-ingredient or contaminated products) rather than the standardized extract itself.

#### Cardiovascular & Blood-Pressure Effects

Theoretical concerns about effects on blood pressure or cardiovascular parameters via androgenic or stimulatory mechanisms have been raised. Controlled trials have not demonstrated meaningful cardiovascular harm at typical doses; this remains mechanistic and anecdotal, with no established outcome data.

## Risk-Modifying Factors

* **Genetic polymorphisms:** Men with certain androgen-receptor sensitivities or *CYP19A1* (aromatase gene) variants might theoretically experience stronger androgenic or estrogenic shifts, though no validated pharmacogenetic guidance exists for Tongkat Ali.

* **Baseline biomarker levels:** Men with already high-normal testosterone, elevated hematocrit (red-blood-cell concentration), or elevated PSA (prostate-specific antigen, a prostate-health marker) have less to gain and more theoretical risk from further androgenic stimulation.

* **Sex-based differences:** Hormonal and androgenic side effects (e.g., acne, voice changes, menstrual effects) are a particular consideration for women, in whom the risk-benefit profile is poorly characterized.

* **Pre-existing health conditions:** Hormone-sensitive conditions (prostate cancer, benign prostatic hyperplasia, breast cancer), significant liver or kidney disease, and uncontrolled cardiovascular disease raise the concern level and make medical oversight prudent.

* **Age-related considerations:** Older adults at the upper end of the target range may have higher prostate-cancer prevalence and reduced organ reserve, modestly increasing the relevance of androgenic and contamination risks.

* **Product source and standardization:** The dominant real-world risk modifier is product quality; contaminated or adulterated products can introduce heavy-metal or undisclosed-ingredient risks independent of any individual factor.

## Key Interactions & Contraindications

* **Antihypertensive and cardiovascular drugs:** Tongkat Ali may have mild effects on blood pressure and, combined with antihypertensives (e.g., lisinopril, amlodipine) or other cardiovascular agents, could theoretically alter blood-pressure control. **Severity:** caution; monitor blood pressure. **Mitigation:** check blood pressure when starting.

* **Anticoagulant and antiplatelet drugs:** Theoretical additive effects with blood-thinning agents (e.g., warfarin, aspirin, clopidogrel) on bleeding risk exist based on antiplatelet activity reported for some botanical constituents. **Severity:** caution; clinical consequence is increased bleeding risk. **Mitigation:** monitor and separate use under medical supervision.

* **Diabetes medications:** Tongkat Ali may modestly affect blood glucose; combined with glucose-lowering drugs (e.g., metformin, insulin, sulfonylureas such as glipizide), it could theoretically increase the risk of low blood sugar. **Severity:** caution; clinical consequence is hypoglycemia. **Mitigation:** monitor blood glucose.

* **Hormone-modulating drugs:** Concurrent use with testosterone replacement, aromatase inhibitors (e.g., anastrozole), or 5-alpha-reductase inhibitors (e.g., finasteride) may produce additive or unpredictable hormonal effects. **Severity:** caution; consequence is hormonal imbalance. **Mitigation:** coordinate with the prescribing clinician.

* **Over-the-counter medications:** Over-the-counter NSAIDs (nonsteroidal anti-inflammatory drugs, e.g., ibuprofen, naproxen) add a theoretical bleeding-risk and gastrointestinal-irritation overlap. **Severity:** caution. **Mitigation:** take with food; avoid heavy concurrent use.

* **Supplement interactions:** Combining with other testosterone- or libido-oriented supplements (e.g., *Tribulus terrestris*, fenugreek, ashwagandha, DHEA (dehydroepiandrosterone, a precursor hormone)) may have additive hormonal effects; combining with other adaptogens (e.g., ashwagandha, rhodiola) may have additive cortisol-lowering effects. **Severity:** caution; consequence is amplified or unpredictable hormonal/stress effects. **Mitigation:** introduce one agent at a time.

* **Stimulant interactions:** Additive overstimulation, restlessness, or insomnia can occur when combined with caffeine or other stimulants. **Severity:** caution. **Mitigation:** dose earlier in the day; limit concurrent stimulants.

* **Populations who should avoid it:** People with hormone-sensitive cancers (prostate cancer, breast cancer), benign prostatic hyperplasia with elevated PSA, significant liver disease (e.g., Child-Pugh Class B or C), severe kidney impairment, those who are pregnant or breastfeeding, children and adolescents, and people scheduled for surgery within two weeks (bleeding-risk caution) should avoid Tongkat Ali.

## Risk Mitigation Strategies

* **Choose third-party-tested, heavy-metal-screened products:** Because heavy-metal contamination is the principal real-world risk, selecting extracts independently tested (e.g., by ConsumerLab or NSF) and screened for mercury, lead, arsenic, and cadmium directly prevents chronic heavy-metal exposure.

* **Use a standardized extract at a conservative dose:** To avoid hormonal overstimulation and unpredictable effects, use a standardized extract (e.g., to a defined eurycomanone percentage) starting at the low end of the studied range — around 100–200 mg daily — rather than crude or megadosed products.

* **Dose in the morning:** To prevent insomnia and overstimulation, take Tongkat Ali earlier in the day, since its stimulating and pro-androgenic effects can disrupt sleep when taken late.

* **Take with food:** To reduce nausea, bitterness-related gastrointestinal upset, and headache, take the supplement with a meal.

* **Screen prostate and hormonal status before and during use:** To mitigate the risk of stimulating an occult hormone-sensitive condition, obtain baseline PSA and testosterone (and reassess periodically), particularly in men over 45, and discontinue if PSA rises meaningfully.

* **Cycle and reassess rather than use indefinitely:** To limit cumulative heavy-metal exposure and unrecognized hormonal effects, use defined cycles (e.g., several weeks on, with breaks) and reassess benefit, rather than continuous open-ended use.

* **Coordinate with a clinician when on interacting medications:** To prevent additive effects with antihypertensive, anticoagulant, glucose-lowering, or hormone-modulating drugs, review use with a prescriber and monitor the relevant parameter (blood pressure, glucose, bleeding signs).

## Therapeutic Protocol

* **Standard practitioner protocol:** Integrative practitioners and the published trials most commonly use a standardized water-soluble root extract (e.g., LJ100, standardized to roughly 22% eurycomanone and 40% eurypeptides) at 200–400 mg per day, or crude-equivalent standardized extracts at 100–300 mg per day, taken for 4–12 weeks before assessing response.

* **Competing approaches:** A conventional approach favors lower, standardized doses (100–200 mg/day) of a single verified extract with monitoring, prioritizing the cortisol/stress and low-T-restoration evidence; an integrative or performance-oriented approach uses higher doses (up to ~400–600 mg/day) and stacks Tongkat Ali with other adaptogens or testosterone-support supplements. Neither is established as superior; the lower-dose, single-agent approach has the cleaner safety and evidence profile.

* **Experts/clinics popularizing approaches:** The standardized LJ100 extract and its dosing were popularized by Malaysian government research institutes (Forest Research Institute Malaysia and MIT/HRM collaborators) and the associated extract developers; the supplement-optimization framing for general users has been amplified by figures such as Andrew Huberman.

* **Best time of day:** Morning dosing is generally preferred to align with the natural morning testosterone peak and to avoid sleep disruption from its stimulating effects.

* **Half-life considerations:** Because eurycomanone's estimated half-life is relatively short (on the order of a few hours), effects are tied to regular daily dosing rather than long plasma persistence.

* **Single vs. split dosing:** A single morning dose is most common and convenient; some protocols split into morning and early-afternoon doses to smooth effects and reduce per-dose gastrointestinal load, but later dosing risks insomnia.

* **Genetic polymorphisms:** No validated pharmacogenetic dosing exists; androgen-receptor CAG-repeat length and *CYP19A1* (aromatase) variants are mechanistically relevant to individual response but are not used to guide dosing in practice.

* **Sex-based differences:** Protocols and evidence are male-oriented; women's dosing is poorly defined, and lower, cautious dosing is typically suggested given androgenic-effect concerns.

* **Age-related considerations:** Older adults at the upper end of the target range often show the best hormonal response but warrant prostate screening and conservative dosing.

* **Baseline biomarkers:** Baseline total and free testosterone, SHBG, and (for men over ~45) PSA help define candidacy and a target against which to judge response.

* **Pre-existing conditions:** Hormone-sensitive conditions, significant liver or kidney disease, and uncontrolled cardiovascular disease argue against use or for close medical supervision.

## Discontinuation & Cycling

* **Lifelong vs. short-term:** Tongkat Ali is generally used as a short-to-intermediate-term or cycled supplement rather than a lifelong daily therapy; long-term continuous safety data are limited, and cumulative contamination exposure is a consideration favoring breaks.

* **Withdrawal effects:** No established physical withdrawal syndrome is reported; on stopping, any testosterone or cortisol changes and subjective benefits gradually revert toward baseline rather than producing rebound symptoms.

* **Tapering:** Because there is no dependence or withdrawal, abrupt discontinuation is acceptable and no formal taper is required; users may simply stop at the end of a cycle.

* **Cycling for efficacy:** Cycling (e.g., 4–8 weeks on followed by 2–4 weeks off, or several weeks on with periodic breaks) is commonly recommended to limit cumulative exposure and to reassess whether the supplement still provides benefit, though no trial has established an optimal cycling schedule for maintaining efficacy.

* **Reassessment on discontinuation:** Each break is an opportunity to recheck testosterone, mood, and stress markers and decide whether continued use is warranted, presented as a bulleted decision point rather than automatic continuation.

## Sourcing and Quality

* **Source and contamination control:** Because the root accumulates heavy metals from soil, sourcing from reputable suppliers with documented heavy-metal testing (mercury, lead, arsenic, cadmium) is the foremost quality consideration.

* **Standardization markers:** Look for extracts standardized to a defined eurycomanone content (often listed as a percentage) and, for patented extracts, eurypeptide content; unstandardized "crude root powder" products have unpredictable potency.

* **Authenticity and adulteration:** Independent testing has found products that are under-dosed, mislabeled, or adulterated; favor brands that publish certificates of analysis and avoid suspiciously cheap or proprietary "blend" products that obscure the actual Tongkat Ali dose.

* **Third-party verification:** Prefer products independently verified by organizations such as ConsumerLab, NSF, or USP, which test for both label accuracy and contaminants.

* **Reputable extracts and brands:** Patented standardized extracts such as LJ100 (and products built on it) are the most studied; reputable supplement brands that disclose extract type, eurycomanone percentage, and third-party testing are preferable to generic imports.

## Practical Considerations

* **Time to effect:** Subjective stress, mood, and energy effects may appear within 1–2 weeks, while measurable testosterone and hormonal changes typically require 4–8 weeks of consistent daily use, with most trials assessing outcomes at 4–12 weeks.

* **Common pitfalls:** Frequent mistakes include using unstandardized or contaminated crude-root products, expecting large testosterone gains in young men with already-normal levels, dosing late in the day and disrupting sleep, megadosing in search of faster results, and stacking multiple hormonal supplements at once so that effects and side effects cannot be attributed.

* **Regulatory status:** In the United States, Tongkat Ali is sold as a dietary supplement and is not FDA-approved for any condition; it is not a regulated drug, so manufacturing quality and label accuracy vary, and some sports organizations scrutinize hormonal supplements for contamination with banned substances.

* **Cost and accessibility:** Tongkat Ali is widely available and generally inexpensive to moderately priced; verified, third-party-tested standardized extracts cost more but are worth the premium given contamination risks. Access is not a significant barrier.

## Interaction with Foundational Habits

* **Sleep:** The interaction is direct and can be negative. Its stimulating, pro-androgenic effects can cause insomnia or restlessness when taken late in the day; conversely, by lowering cortisol it may indirectly support sleep in chronically stressed users. Practical consideration: dose in the morning to avoid sleep disruption.

* **Nutrition:** The interaction is indirect. Taking Tongkat Ali with food reduces its bitterness-related gastrointestinal upset and nausea; adequate protein, zinc, and overall energy intake support endogenous testosterone production and may complement any hormonal effect. No specific diet is required, and no clinically important nutrient depletion is established.

* **Exercise:** The interaction is potentiating but modest. By lowering cortisol and modestly supporting testosterone, Tongkat Ali may aid recovery and the testosterone-to-cortisol ratio around resistance training; small studies pairing it with training show inconsistent strength and body-composition gains. Practical consideration: any ergogenic effect is secondary to the training stimulus itself, and morning dosing aligns with typical training and hormonal rhythms.

* **Stress management:** The interaction is direct and potentiating. Its best-supported effect is cortisol reduction and improved stress resilience, so it complements stress-management practices (sleep, breathwork, reduced training overload); combining it with other adaptogens such as ashwagandha may be additive but makes individual effects harder to attribute.

## Monitoring Protocol & Defining Success

Before starting, a baseline assessment establishes hormonal status and screens for contraindications so that response can be judged against a personal starting point rather than population norms. Ongoing monitoring follows a cadence of roughly 4–8 weeks after starting (to capture hormonal change), then every 3–6 months during continued or cycled use, with PSA reassessed at least annually in men over 45.

| Biomarker | Optimal Functional Range | Why Measure It? | Context/Notes |
|---|---|---|---|
| Total testosterone | 500–900 ng/dL (men) | Primary target outcome | Conventional reference range is broader (~264–916 ng/dL); draw in the morning, fasting preferred; the functional optimum sits in the upper half. SHBG = sex hormone-binding globulin. |
| Free testosterone | 15–25 pg/mL (men) | Biologically active fraction | Often more responsive than total T to SHBG changes; calculate or measure alongside SHBG and albumin. |
| SHBG | 20–45 nmol/L | Determines free vs. bound T | SHBG (sex hormone-binding globulin) binds testosterone; Tongkat Ali may lower it, raising free T. Pair with total T. |
| Estradiol (E2) | 20–30 pg/mL (men) | Detects aromatization shifts | Estradiol is the main estrogen; rising E2 with higher T suggests aromatase activity. Use a sensitive assay. |
| Cortisol (morning) | 10–18 µg/dL (a.m.) | Tracks stress-axis / adaptogen effect | Cortisol is the primary stress hormone; salivary diurnal testing better captures Tongkat Ali's stress effect. Best measured ~8 a.m. |
| PSA | < 2.5 ng/mL (men > 45) | Prostate safety screen | PSA = prostate-specific antigen; rising values warrant urological evaluation before continuing. Avoid testing soon after ejaculation or vigorous cycling. |
| Hematocrit | 40–48% (men) | Detects androgenic blood thickening | Hematocrit is the red-blood-cell fraction; androgenic stimulation can raise it. Pair with a complete blood count. |
| ALT / AST | < 30 U/L | Liver-safety screen for botanicals | ALT/AST are liver enzymes; elevations may signal supplement-related liver stress. Fasting preferred; recheck if symptoms arise. |

Qualitative markers should also be tracked, as they often reflect benefit before or beyond lab changes:

* Energy levels and daytime fatigue
* Mood, irritability, and subjective stress or tension
* Libido and sexual well-being
* Sleep quality and ease of falling asleep
* Training recovery and perceived strength
* Motivation and sense of overall vitality

## Emerging Research

* **Eurycoma longifolia trial in infertile men:** A Phase 4 randomized trial evaluating a standardized *Eurycoma longifolia* extract (DLBS5055) with multivitamins in infertile males (~90 participants) is registered at [NCT06100432](https://clinicaltrials.gov/study/NCT06100432), examining reproductive and hormonal endpoints.

* **Tongkat Ali combination trial for sexual function:** A completed randomized trial assessing a Tongkat Ali–Maca combination on erectile function (~197 participants) is registered at [NCT05347329](https://clinicaltrials.gov/study/NCT05347329), with sexual-function and tolerability endpoints relevant to the supplement's claimed benefits.

* **Meta-analytic clarification of testosterone effect size:** Future and updated meta-analyses building on [Leisegang et al., 2022](https://pubmed.ncbi.nlm.nih.gov/36013514/) could strengthen the case by confirming a reproducible testosterone increase, or weaken it by showing the effect is driven by small, manufacturer-linked, low-baseline studies once higher-quality trials are pooled.

* **Independent general-population evidence:** Work following [Morgado et al., 2024](https://pubmed.ncbi.nlm.nih.gov/37697053/), which rated *Eurycoma longifolia* only "possibly effective", could weaken the general-use case if larger trials continue to show no meaningful testosterone benefit in men with normal baseline levels.

* **Cortisol and stress-resilience mechanism:** Better-powered trials isolating the cortisol-lowering and stress-buffering effect could strengthen the strongest current signal and clarify whether stress reduction, rather than direct steroidogenesis, drives most observed benefit.

* **Long-term safety and contamination surveillance:** Emerging product-quality and toxicology surveillance could weaken the risk-benefit case if chronic heavy-metal exposure proves common, or strengthen confidence if standardized, tested extracts demonstrate clean long-term safety.

## Conclusion

Tongkat Ali is a root extract from a Southeast Asian shrub, sold as a supplement and marketed to raise testosterone, ease stress, and improve sexual function. Rather than supplying hormone directly, it is thought to support the body's own testosterone production and to lower the main stress hormone. The most dependable finding across studies is a modest reduction in stress-hormone levels and improved stress resilience. A measurable rise in testosterone appears mainly in older men or those who start with low levels, while younger men with normal levels tend to see little change. Improvements in fertility, libido, strength, and general energy have also been reported, though on weaker evidence.

The evidence base is made up largely of small studies, some tied to extract makers, with differing product standards, so the size of the testosterone effect remains genuinely uncertain. The clearest real-world concern is not the compound itself but product quality, since independent testing has found heavy-metal contamination in some products. Side effects in trials are generally mild, such as restlessness, sleep disruption, or stomach upset.

This review has laid out what is known and what remains unsettled, so that a careful reader can weigh the modest, baseline-dependent benefits against the quality and contamination considerations involved.

**[Top](#top) - [Benefits](#expected-benefits) - [Risks](#potential-risks--side-effects) - [Protocol](#therapeutic-protocol)**


Tongue Cleaning
Tongue Scraper
Tongue Cleaner
Jihva Nirlekhana

---
canonical_name: Tongue Scraping
alternate_names: Tongue Cleaning, Tongue Scraper, Tongue Cleaner, Jihva Nirlekhana
canonical_topic: Tongue Scraping for Health & Longevity
short_topic_lc: tongue_scraping
creation_date: 2026-0713-0451
creator_ai_fullname: Opus 4.8
---

# Tongue Scraping for Health & Longevity

Evidence Review created on 07/13/2026 using [AI4L](https://github.com/forever-healthy/AI4L) / Opus 4.8

**Also known as:** Tongue Cleaning, Tongue Scraper, Tongue Cleaner, Jihva Nirlekhana

## Motivation

Tongue scraping is the daily practice of drawing a small handheld tool across the top of the tongue to remove the soft, pale film that builds up there overnight. That film is a mix of food particles, dead surface cells, and bacteria. Because the back of the tongue is one of the largest reservoirs of microbes in the mouth, clearing it is one of the simplest, cheapest additions to a brushing-and-flossing routine.

The habit is ancient. It is described in classical Indian medical texts and has been practiced across many cultures for thousands of years using tools of copper, silver, or brass. Modern interest has grown for two reasons: it is the most direct way to reduce bad breath, and the tongue's bacteria play a surprising role in the body's handling of dietary nitrate, a step in the natural production of a molecule that helps relax blood vessels.

This review examines what the evidence shows about tongue scraping across its claimed effects, from fresher breath and sharper taste to its possible place in whole-body and long-term health. It weighs the strength of that evidence, notes where findings conflict, and describes how the practice is typically performed.

**[Benefits](#expected-benefits) - [Risks](#potential-risks--side-effects) - [Protocol](#therapeutic-protocol) - [Conclusion](#conclusion)**

## Recommended Reading

This section lists high-level overviews from clinicians and researchers that place tongue scraping within oral hygiene and the broader oral-microbiome-to-body connection.

* [Don't Underestimate the Importance of Oral Health](https://peterattiamd.com/importance-of-oral-health/) - Peter Attia

  A clinician's overview of why the oral microbiome matters far beyond the mouth, using hospital data on toothbrushing and pneumonia to argue that everyday oral hygiene has whole-body consequences.

* [How to Improve Your Teeth & Oral Microbiome for Brain & Body Health – Dr. Staci Whitman](https://www.hubermanlab.com/episode/how-to-improve-your-teeth-oral-microbiome-for-brain-body-health-dr-staci-whitman) - Andrew Huberman

  A long-form podcast with a dentist that specifically covers tongue scraping, the harms of harsh antiseptic products, and the link between tongue bacteria and nitric oxide production.

* [Nitric Oxide and Oral Health](https://askthedentist.com/nitric-oxide-oral-health/) - Mark Burhenne

  A dentist explains the nitrate-to-nitric-oxide pathway in plain language and why preserving beneficial tongue bacteria, rather than sterilizing the mouth, is central to cardiovascular and general health.

* [Perspectives on tongue coating: etiology, clinical management, and associated diseases](https://pubmed.ncbi.nlm.nih.gov/40833644/) - AlBeshri, 2025

  A recent narrative review that describes what tongue coating is made of, how it forms, its links to halitosis and systemic disease, and the mechanical and chemical ways to manage it.

* [Tongue cleaning in the elderly and its role in the respiratory and swallowing functions](https://pubmed.ncbi.nlm.nih.gov/34612518/) - Izumi & Akifusa, 2021

  A narrative review focused on older adults, describing how tongue coating relates to aspiration pneumonia and how daily tongue cleaning may support swallowing and breathing function.

Content from Rhonda Patrick (FoundMyFitness), Chris Kresser, and Life Extension is not listed because a direct search of each platform returned no article or episode dedicated to tongue scraping or tongue cleaning; their nearest material addresses the oral microbiome and nitric oxide only at a general level.

## Grokipedia

* [Tongue cleaner](https://grokipedia.com/page/Tongue_cleaner)

  The dedicated Grokipedia entry for the intervention, summarizing tongue-cleaning tools, techniques, evidence for reducing coating and malodour, and noted risks such as rare material allergies.

## Examine

No dedicated Examine article exists for tongue scraping. Examine.com covers supplements, foods, and dietary compounds, and does not maintain a page for mechanical oral-hygiene tools or practices.

## ConsumerLab

No dedicated ConsumerLab article exists for tongue scraping. ConsumerLab independently tests supplements and consumable health products, and does not review mechanical oral-hygiene devices such as tongue scrapers.

## Systematic Reviews

The following systematic reviews and meta-analyses assess tongue cleaning for tongue coating, bad breath, and taste, and represent the highest tier of available human evidence.

* [Interventions for managing halitosis](https://pubmed.ncbi.nlm.nih.gov/31825092/) - Kumbargere Nagraj et al., 2019

  This Cochrane review pooled 44 randomized controlled trials (RCTs — studies that randomly assign participants to compare treatments) and folded in the earlier Cochrane review on tongue scraping. For mechanical tongue cleaning versus none it found a reduction in dentist-judged breath scores but rated the certainty very low, reflecting small, short trials. Much halitosis research is funded by manufacturers of mouthwashes and toothpastes, whose commercial interest lies in chemical products rather than a low-cost scraper, a structural bias worth keeping in mind when weighting the literature.

* [Effectiveness of mechanical tongue cleaning on breath odour and tongue coating: a systematic review](https://pubmed.ncbi.nlm.nih.gov/20961381/) - Van der Sleen et al., 2010

  A focused review of five controlled studies (seven experiments) comparing scraping or tongue brushing added to toothbrushing against toothbrushing alone. Every experiment showed a positive effect on breath odour and tongue coating, though the authors cautioned that data on long-standing (chronic) bad breath remain thin.

* [Toothbrushing versus toothbrushing plus tongue cleaning in reducing halitosis and tongue coating: a systematic review and meta-analysis](https://pubmed.ncbi.nlm.nih.gov/24165218/) - Kuo et al., 2013

  A meta-analysis (a study that statistically pools results from multiple trials) of five RCTs that quantified the added benefit of tongue cleaning. It reported large pooled effects for reducing both the smelly sulfur gases behind bad breath and visible tongue coating, while noting that the best frequency and technique are still undefined.

* [Efficacy of mechanical tongue cleaning on taste perception: a systematic review](https://pubmed.ncbi.nlm.nih.gov/40243105/) - Costantinides et al., 2025

  A recent review of four studies examining whether clearing the tongue coating improves taste. All studies found better taste sensitivity after cleaning, though the improvement was not always statistically significant for every flavour, supporting a real but modest effect.

* [Treatment of oral malodour. Medium-term efficacy of mechanical and/or chemical agents: a systematic review](https://pubmed.ncbi.nlm.nih.gov/25682952/) - Slot et al., 2015

  A review restricted to trials lasting at least two weeks, addressing the common criticism that most tongue-cleaning studies are very short. It found the medium-term benefit of a tongue scraper used alone to be unclear, with the strongest (though still weak) evidence attaching to certain active-ingredient mouthwashes.

## Mechanism of Action

Tongue scraping works by mechanical removal rather than by any chemical or drug action. The top surface of the tongue (the dorsum) is covered in tiny projections and crevices that trap food debris, shed cells, white blood cells, and a dense bacterial biofilm — together forming the visible tongue coating. Scraping physically lifts and clears this layer.

The main pathways by which this produces effects are:

* **Reduction of odour-producing bacteria and their fuel.** The tongue coating is dominated by oxygen-avoiding (anaerobic) bacteria such as *Solobacterium moorei*, *Prevotella*, and *Fusobacterium* species. These break down sulfur-containing proteins into volatile sulfur compounds (VSCs — smelly sulfur gases such as hydrogen sulfide and methyl mercaptan), the principal cause of bad breath. Removing the coating lowers both the bacterial load and the protein debris they feed on.

* **Unblocking taste receptors.** A thick coating forms a diffusion barrier over the taste buds. Clearing it appears to let dissolved food molecules reach the receptors more readily, which is the proposed basis for improved taste sensitivity after cleaning.

* **Interaction with the nitrate–nitric oxide pathway.** Certain beneficial tongue bacteria (including *Rothia*, *Neisseria*, and *Veillonella*) reduce dietary nitrate from vegetables into nitrite, which the body then converts to nitric oxide (NO — a signaling molecule that relaxes blood vessels and helps regulate blood pressure). This is called the enterosalivary pathway, because swallowed nitrate is recycled through saliva. The body also makes nitric oxide directly using an enzyme called endothelial nitric oxide synthase (eNOS — the enzyme that produces nitric oxide inside blood-vessel walls), but the bacterial route is an important supplement to it.

Where the mechanistic picture becomes contested is whether removing the coating helps or harms this last pathway. One view holds that gentle daily scraping clears mostly harmful anaerobes while leaving the deeper, more adherent nitrate-reducing community intact — and that regular cleaners maintain a healthier balance. The opposing view is that any disruption of the tongue biofilm risks depleting the very bacteria that generate nitric oxide. Human data lean toward the first interpretation for mechanical scraping (as opposed to harsh antiseptics), but the question is unsettled and is treated as conflicted throughout this review.

Tongue scraping is not a pharmacological compound, so properties such as half-life, tissue distribution, selectivity, and enzymatic metabolism do not apply.

## Historical Context & Evolution

Tongue scraping originated as a hygiene and health practice, not as a treatment for any specific disease. It is documented in the classical Ayurvedic texts of ancient India (the Charaka Samhita and Sushruta Samhita), which describe daily tongue cleaning (jihva nirlekhana) with thin curved strips of gold, silver, copper, tin, or brass as part of morning self-care. Similar practices appear historically across the Middle East, parts of Europe, South America, and East Asia, where the tongue's coating was long regarded as something to be cleared each morning.

Its move into modern health optimization came through two separate channels. The first was dentistry and the study of bad breath: as researchers identified the tongue coating as the dominant source of the sulfur gases responsible for oral malodour, mechanical tongue cleaning was studied and recommended as a targeted countermeasure. The second, more recent channel was microbiome and cardiovascular science, which revealed that tongue bacteria contribute to the body's nitric-oxide supply — reframing the tongue's surface not merely as a source of odour but as a metabolically active organ relevant to blood-pressure regulation.

The findings that drove this evolution have not been overturned so much as complicated. Early enthusiasm that "cleaner is better" has been tempered by evidence that indiscriminate chemical sterilization of the mouth can raise blood pressure, prompting a more nuanced position that distinguishes gentle mechanical cleaning from aggressive antiseptic use. What changed was not a reversal but the addition of a second consideration — the microbiome's beneficial functions — alongside the original hygiene rationale. The current standing is best read as an active, still-developing balance rather than a settled conclusion.

## Expected Benefits

### High 🟩 🟩 🟩

#### Reduction of Tongue Coating

Mechanical clearing of the tongue coating is the most consistently demonstrated effect, which is unsurprising given that scraping directly removes the coating being measured. Multiple controlled trials, pooled in the Kuo meta-analysis and the Van der Sleen review, show that adding tongue cleaning to toothbrushing reduces visible coating more than brushing alone. The effect is immediate and repeatable, and it is the mechanical basis for the downstream breath and taste benefits.

**Magnitude:** In the Kuo meta-analysis, adding tongue cleaning reduced tongue coating with a large pooled standardized effect size (a measure of how big a difference is) of about 0.92 versus toothbrushing alone.

### Medium 🟩 🟩

#### Reduction of Bad Breath

Bad breath (halitosis) in otherwise healthy people arises mainly from sulfur gases produced on the tongue, so clearing the coating targets the source directly. Systematic reviews consistently find that tongue cleaning lowers both the measured sulfur compounds and trained-assessor (organoleptic) breath scores. The grade is held at Medium rather than High because the trials are short, small, and rated low-certainty by Cochrane, and because the durability of the benefit beyond a few weeks is not well established.

**Magnitude:** The Kuo meta-analysis reported a large pooled effect (standardized effect size about 0.75) for reducing sulfur compounds; the Cochrane review found a smaller mean difference (MD — the average difference between groups) of about -0.20 on organoleptic scores.

#### Improved Taste Perception

Removing the coating appears to restore some taste sensitivity by unblocking the taste buds. The 2025 systematic review of four studies found improved detection of flavours after mechanical cleaning in every study, consistent with the mechanism, though the gains were not statistically significant for every taste in every trial. The benefit is plausible and directionally consistent but modest and based on small studies.

**Magnitude:** Not quantified in available studies.

### Low 🟩

#### Reduced Aspiration Pneumonia Risk in Frail Older Adults

In older, frail, or institutionalized individuals, a heavily coated and dysbiotic (microbially imbalanced) tongue is a reservoir for bacteria that can be inhaled into the lungs. A narrative review and small intervention work summarized by Izumi and Akifusa suggest that daily tongue cleaning improves tongue pressure, swallowing, and respiratory measures, which may lower aspiration risk. This benefit is most relevant to the older end of the target audience and rests on limited, indirect evidence rather than large trials with pneumonia as the endpoint.

**Magnitude:** Not quantified in available studies.

### Speculative 🟨

#### Support of the Nitrate–Nitric Oxide Pathway ⚠ Conflicted

Because nitrate-reducing bacteria on the tongue feed the body's nitric-oxide supply, regular tongue care combined with a nitrate-rich diet has been proposed to support healthy blood pressure. The Tribble study linked routine tongue-microbiome management and dietary nitrate to lower resting systolic blood pressure (the top number in a blood-pressure reading), while showing that harsh antiseptic mouthwash raised it. The evidence is conflicted: the same logic that makes cleaning potentially helpful also raises the concern that removing biofilm could strip beneficial bacteria, and no trial has isolated mechanical scraping's independent effect on blood pressure. The basis here is mechanistic and drawn from a single small human study.

#### Systemic and Gut-Microbiome Effects

Because tongue bacteria are continually swallowed, the tongue coating contributes to the community reaching the gut, and a lower oral bacterial burden has been hypothesized to reduce low-grade whole-body inflammation. Associations between tongue coating and conditions such as cardiovascular and metabolic disease have been reported, but these are correlational and do not establish that scraping changes systemic outcomes. This remains an area of hypothesis rather than demonstrated benefit.

## Benefit-Modifying Factors

* **Genetic makeup of the nitric-oxide system:** People whose bodies produce less nitric oxide through the direct enzyme route (for example, certain eNOS gene variants — the gene for the enzyme that makes nitric oxide) may depend more heavily on the bacterial nitrate pathway, making the microbiome-related effects of tongue care potentially more relevant for them.

* **Baseline tongue coating and biomarker status:** Those who start with a thick coating, higher baseline sulfur-gas readings, or elevated blood pressure have more room for measurable improvement than those who begin near-clean; the benefit is proportional to the starting burden.

* **Sex-based differences:** Some tongue-coating and halitosis studies enroll more men than women and report differing baseline coating, but no consistent sex difference in the response to scraping has been established; this remains under-studied.

* **Pre-existing oral conditions:** Smokers, people with dry mouth (reduced saliva), gum disease (periodontitis), or a naturally fissured or geographic tongue tend to accumulate more coating and may see larger coating and breath benefits, though a fissured tongue can be harder to clean completely.

* **Age:** Older adults accumulate coating more readily due to reduced saliva, weaker tongue movement, and lower immune activity, so the coating-clearing and swallowing-related benefits are often more pronounced at the older end of the target range.

## Potential Risks & Side Effects

### Medium 🟥 🟥

#### Soft-Tissue Trauma and Abrasion

Excessive pressure, sharp-edged tools, or over-frequent scraping can abrade or irritate the tongue surface, damage the taste-bud-bearing papillae, or cause minor bleeding. The mechanism is simple mechanical injury to a delicate mucosal surface. Such injury is generally minor and reversible when technique is corrected, and it is avoided by using a smooth-edged scraper with gentle pressure.

**Magnitude:** Not quantified in available studies.

#### Gag Reflex and Discomfort

Placing the scraper too far back on the tongue triggers the pharyngeal gag reflex, causing retching or discomfort. This is the most commonly reported nuisance effect and is a frequent reason people abandon the habit. It is transient and harmless, and is minimized by starting mid-tongue and only gradually working further back as tolerance develops.

**Magnitude:** Not quantified in available studies.

### Low 🟥

#### Transient Taste Alteration

Very aggressive or excessive scraping can temporarily dull rather than sharpen taste by irritating the taste buds, the opposite of the intended effect. This is uncommon, short-lived, and resolves once gentler technique is adopted. It is essentially a dose-related consequence of over-doing an otherwise beneficial practice.

**Magnitude:** Not quantified in available studies.

#### Disruption of Nitrate-Reducing Bacteria ⚠ Conflicted

There is a theoretical concern that removing the tongue biofilm could deplete the beneficial bacteria that generate nitric oxide, potentially nudging blood pressure upward. The evidence is conflicted and, on balance, reassuring for mechanical scraping: the clearest blood-pressure increases in human studies came from chemical antiseptics such as chlorhexidine, not from physical cleaning, and regular cleaners in the Tribble study showed a favourable rather than depleted nitrate-reducing profile. No study has shown that ordinary gentle scraping meaningfully lowers nitric-oxide capacity.

**Magnitude:** Not quantified in available studies.

### Speculative 🟨

#### Oral-Microbiome Depletion with Excessive Cleaning

Repeated, very frequent, and aggressive tongue cleaning could in principle reduce the diversity of the tongue's microbial community over time, with unknown long-term consequences. No controlled data demonstrate this for scraping performed at ordinary daily frequency, and the concern is drawn by analogy from antiseptic-overuse studies rather than from direct evidence.

## Risk-Modifying Factors

* **Genetic and metabolic dependence on bacterial nitric oxide:** Individuals who rely more on the bacterial nitrate pathway (for example, those with lower direct eNOS-driven nitric-oxide output) would in theory be more sensitive to any microbiome disruption, making gentle, non-antiseptic technique more important for them.

* **Baseline blood pressure:** People with elevated or borderline-high blood pressure have the most to lose from any reduction in nitrate-reducing bacteria, so they are the group for whom the mechanical-versus-antiseptic distinction matters most.

* **Sex-based differences:** No consistent sex-specific difference in tongue-scraping risks has been documented; reported differences in oral microbiome composition between men and women have not translated into demonstrated differences in side effects.

* **Pre-existing conditions:** Those with bleeding disorders or on blood-thinning medication are more prone to minor bleeding from trauma; people with active mouth ulcers, oral lesions, a strong gag reflex, or high dental anxiety are more likely to experience discomfort or injury.

* **Age:** Older adults may have thinner, more fragile mucosa and reduced saliva, raising the chance of abrasion, while the frail elderly may need assisted or supervised cleaning to perform it safely.

## Key Interactions & Contraindications

* **Prescription medications:** Tongue scraping has no pharmacological interactions. The only practical caution is for people on anticoagulant or antiplatelet drugs (blood thinners), in whom vigorous scraping could provoke minor mucosal bleeding — a caution, not a contraindication, managed by gentle technique.

* **Over-the-counter products — antiseptic mouthwash:** Combining tongue scraping with routine use of strong antiseptic mouthwashes (for example, chlorhexidine or high-alcohol rinses) is the interaction of greatest interest, because the mouthwash — not the scraping — is what has been shown to suppress nitrate-reducing bacteria and transiently raise blood pressure. Severity: caution; consequence: possible blunting of the nitric-oxide pathway. Mitigation: favour mechanical cleaning over habitual antiseptic rinsing.

* **Supplement interactions:** Oral probiotic lozenges and dietary nitrate or beetroot supplements interact with the same tongue bacteria that scraping targets; gentle scraping is compatible with both and is not expected to negate them, whereas antiseptic rinses would.

* **Additive effects:** Antiseptic mouthwashes, tongue scraping, and vigorous brushing all reduce the tongue biofilm and can be additive in disturbing it; stacking several aggressive measures at once is the scenario most likely to over-deplete beneficial bacteria.

* **Other interventions:** Tongue scraping complements toothbrushing, flossing, and oil pulling; it is best viewed as one component of an overall oral-hygiene routine rather than a standalone measure, and it addresses a site (the tongue dorsum) that brushing and flossing largely miss.

* **Populations who should avoid or modify it:** People with active oral ulceration, recent oral or tongue surgery, oral cancer or suspicious lesions, uncontrolled bleeding disorders, or a severe unmanageable gag reflex should avoid or defer the practice until the condition is resolved or supervised.

* **Population thresholds:** Practical caution applies to specific groups — for example, active oral mucosal lesions or ulcers, the immediate post-operative period after oral surgery (roughly the first 1–2 weeks or until cleared by a clinician), and clinically significant thrombocytopenia (a low platelet count that impairs clotting) or therapeutic anticoagulation (such as an INR — international normalized ratio, a measure of blood-clotting time — above the intended therapeutic range) — rather than to broad categories alone.

## Risk Mitigation Strategies

* **Smooth, purpose-made scraper with light pressure:** A rounded-edge stainless-steel, copper, or medical-grade plastic scraper used with gentle pressure prevents the soft-tissue abrasion and bleeding that come from sharp edges or force; knife-edged or damaged tools are the ones associated with injury.

* **Front-to-back scraping within tolerance, not deep-to-gag:** Starting at the middle of the tongue and extending backward only as far as is comfortable, advancing gradually over days, avoids triggering the gag reflex that causes most discomfort and dropout.

* **Limited frequency of once or twice daily:** Cleaning once in the morning and optionally once at night is sufficient; capping frequency at roughly twice daily prevents the over-cleaning that underlies the speculative concerns about mucosal irritation and microbiome depletion.

* **Preference for mechanical cleaning over habitual antiseptic rinsing:** Favouring a scraper rather than daily strong antiseptic mouthwash sidesteps the one oral-care behaviour clearly linked to suppressed nitric-oxide bacteria and raised blood pressure, directly mitigating the pathway-disruption risk.

* **Rinsing and drying the tool, and replacing it when worn:** Rinsing the scraper after each stroke and between uses, and replacing metal tools when edges roughen or plastic tools every few months, prevents reintroducing debris and reduces the chance of scratching the tongue.

* **Deferral during active oral injury:** Pausing the practice when mouth ulcers, lesions, or post-surgical healing are present avoids aggravating trauma and bleeding until the tissue has recovered.

## Therapeutic Protocol

* **Core technique:** Practitioners of oral hygiene describe extending the tongue, placing the scraper as far back as is comfortable, and drawing it forward along the midline and both sides in slow, gentle strokes, rinsing the tool between strokes, for roughly 5–10 passes until the coating is cleared.

* **Conventional versus traditional approaches:** Two main approaches coexist and are presented without ranking one as default. The conventional dental approach uses a U-shaped stainless-steel or plastic scraper (or the back of a toothbrush) as an adjunct to brushing. The traditional Ayurvedic approach, which popularized the practice, favours a curved copper or silver scraper used first thing in the morning before eating or drinking; copper is valued in that tradition for its antibacterial surface.

* **Originators and proponents:** The morning-routine, metal-scraper method traces to classical Ayurvedic medicine and is promoted today by integrative-health practitioners; the adjunct-to-brushing framing is advanced by dental and dental-hygiene sources and by clinicians discussing the oral microbiome.

* **Best time of day:** Morning is the primary time, because the coating accumulates overnight when saliva flow and swallowing fall; an optional evening pass before bed can further reduce the overnight bacterial load. Scraping before rather than after eating avoids disturbing freshly cleared tissue.

* **Pharmacokinetic considerations:** As a mechanical practice, tongue scraping has no half-life, and single-versus-split dosing does not apply; the analogous parameter is frequency, addressed above as once or twice daily.

* **Genetic considerations:** No pharmacogenetic testing guides the practice, but individuals who depend more on bacterial nitric-oxide production (for example, some eNOS variants) have extra reason to keep cleaning gentle and mechanical rather than antiseptic.

* **Sex-based considerations:** No sex-specific technique or frequency differences are established; the same protocol applies to men and women.

* **Age-related considerations:** Older adults, who accumulate more coating, benefit from consistent daily cleaning, but frail individuals may need a softer mucosal brush rather than a rigid scraper and, in some cases, assistance to perform it safely.

* **Baseline biomarker considerations:** Those beginning with a heavy coating or high sulfur-gas readings will typically clear more material initially and can taper technique as the baseline coating diminishes.

* **Pre-existing-condition considerations:** People with dry mouth, gum disease, or a fissured tongue may need slightly more thorough or frequent cleaning, while those with mouth lesions should defer until healed.

## Discontinuation & Cycling

* **Lifelong versus short-term:** Tongue scraping is intended as an ongoing daily habit rather than a time-limited course; its benefits depend on continued practice, much like brushing.

* **Withdrawal effects:** There are no physiological withdrawal effects. Stopping simply allows the tongue coating, and the bad breath it can cause, to return to baseline within days.

* **Tapering:** No tapering is required or meaningful; the practice can be started or stopped freely without any adjustment period.

* **Cycling:** Cycling is not necessary for maintaining effectiveness, since the benefit is mechanical and does not diminish with continued use. If anything, the only reason to reduce frequency is to avoid over-cleaning, not to preserve efficacy.

* **Practical note:** Because the effect is not cumulative in the way a drug's is, consistency matters more than intensity — a gentle daily pass sustains the benefit better than infrequent aggressive sessions.

## Sourcing and Quality

* **Material choice:** Common scraper materials are stainless steel, copper, and medical-grade plastic. Stainless steel is durable, non-reactive, and easy to sanitize; copper is favoured in the Ayurvedic tradition for its naturally antibacterial surface; plastic is inexpensive but wears and harbours scratches more readily.

* **What to look for:** A quality scraper has smooth, rounded edges (never sharp), a comfortable grip, a single-piece or easily cleaned design, and enough rigidity to lift coating without flexing away; dishwasher-safe metal tools are easiest to keep hygienic.

* **Reputable options:** Well-regarded consumer brands include DrTung's, MasterMedi, and various copper-scraper makers; any tool meeting the edge-smoothness and cleanability criteria above is generally adequate, as this is a simple, low-technology device.

* **Purity and safety considerations:** Because there is no ingested substance, third-party purity testing is not applicable in the supplement sense; the relevant quality checks are material safety (food-grade metal or BPA-free plastic), absence of sharp burrs, and corrosion resistance for metal tools.

* **Replacement:** Metal scrapers last for years but should be replaced if edges roughen or corrode; plastic scrapers should be replaced every few months as they wear.

## Practical Considerations

* **Time to effect:** The coating-clearing, breath, and taste effects are essentially immediate — noticeable from the first use and each morning thereafter; any microbiome-related shifts, if real, would develop over weeks of consistent practice.

* **Common pitfalls:** The frequent mistakes are pressing too hard (causing irritation), reaching too far back too soon (triggering gagging), neglecting to rinse the tool, over-cleaning in the belief that more is better, and substituting habitual harsh antiseptic mouthwash for gentle mechanical cleaning.

* **Regulatory status:** Tongue scrapers are marketed as general oral-hygiene devices and are not regulated as drugs; in the United States they fall under low-risk device oversight, and the practice itself carries no prescription or approval requirement.

* **Cost and accessibility:** The practice is exceptionally low-cost and widely accessible — a durable scraper typically costs a few dollars to around fifteen dollars and lasts for years — so cost is not a barrier and is secondary to effectiveness.

* **Consistency over equipment:** A modest tool used daily outperforms an expensive one used sporadically; the determining factor is habit, not the specific device.

## Interaction with Foundational Habits

* **Sleep:** The interaction is indirect. Tongue coating and morning bad breath are worst on waking because saliva flow and swallowing decline during sleep, and mouth-breathing overnight worsens both; this is why morning is the primary cleaning time. Scraping does not affect sleep itself, but it directly addresses the overnight buildup that sleep produces.

* **Nutrition:** The interaction is direct and two-way. A diet rich in vegetables supplies the nitrate that tongue bacteria convert toward nitric oxide, so gentle mechanical cleaning is best paired with — not substituted by — a nitrate-rich diet; harsh antiseptic rinsing would undercut this, whereas scraping does not. Diets high in dairy, sugar, or alcohol, and dehydration, tend to increase coating and may call for more attentive cleaning.

* **Exercise:** The interaction is indirect and potentially potentiating. Because nitric oxide supports blood-vessel dilation and exercise capacity, preserving the tongue's nitrate-reducing bacteria — by cleaning mechanically rather than with antiseptics — may help maintain the nitrate-to-nitric-oxide route that some athletes rely on when using dietary nitrate for performance.

* **Stress management:** The interaction is minimal and mainly practical. A strong gag reflex is heightened by anxiety, so a calm, unhurried approach makes the practice easier to sustain; there is no established effect of tongue scraping on cortisol or the physiological stress response.

## Monitoring Protocol & Defining Success

Because tongue scraping is a low-risk lifestyle practice rather than a medical treatment, formal laboratory monitoring is generally not required, and success is judged mainly by simple daily observation. The measures below are optional and are most relevant for those interested in the blood-pressure and nitric-oxide dimension.

Before starting, an interested individual can note their baseline: the typical appearance of the morning coating, whether bad breath is a concern, and — for those tracking the cardiovascular angle — a resting blood-pressure reading. Ongoing checks are largely qualitative and continuous; for anyone monitoring blood pressure, a reasonable cadence is a baseline reading, a re-check after several weeks of consistent practice, and thereafter every 6–12 months or as otherwise indicated.

| Biomarker | Optimal Functional Range | Why Measure It? | Context/Notes |
|-----------|--------------------------|-----------------|----------------|
| Resting systolic blood pressure | Under ~120 mmHg | Tracks the nitrate–nitric-oxide pathway that tongue bacteria help supply | Measure seated after 5 minutes' rest; avoid caffeine beforehand; conventional "normal" extends to <130 mmHg, so the functional target is tighter |
| Tongue coating (visual self-check, Winkel-style) | Minimal to no visible coating | Directly gauges the biofilm burden the practice targets | Check in the morning before eating or cleaning, in good light |
| Plasma or salivary nitrite (optional, advanced) | Detectable, within normal laboratory range | Reflects the capacity of tongue bacteria to reduce nitrate | Specialized/research labs only; not needed for routine practice; best interpreted alongside dietary nitrate intake |

Qualitative markers of success include:

* Fresher breath on waking and through the day
* A cleaner, less-coated tongue appearance
* Sharper or more vivid taste, especially of subtle flavours
* A less "furry" or filmy mouthfeel in the morning

## Emerging Research

* **Ongoing halitosis trial isolating the scraper's contribution:** A recruiting randomized trial, [NCT06091228](https://clinicaltrials.gov/study/NCT06091228), is testing the additional effect of tongue scraping on bad-breath measures within initial gum-disease therapy (about 39 participants, organoleptic breath score as the primary endpoint), directly addressing the gap in trials that isolate scraping's own contribution.

* **Oral-hygiene and vascular-function trial:** A recruiting study, [NCT07311512](https://clinicaltrials.gov/study/NCT07311512), examines professional mechanical plaque removal and chlorhexidine in gum disease alongside vascular function and endothelial measures (about 30 participants), and is relevant to the mechanical-versus-antiseptic question central to tongue care.

* **Dietary-nitrate trial probing the same pathway:** A not-yet-recruiting feasibility study of beetroot-juice nitrate in Alzheimer's disease, [NCT07258004](https://clinicaltrials.gov/study/NCT07258004) (about 30 participants), reflects growing interest in the nitrate-to-nitric-oxide route that tongue bacteria enable, a pathway that tongue-care practices could modulate.

* **Direction that could strengthen the case:** The most consequential published finding is that regular tongue-microbiome management plus dietary nitrate tracked with lower resting blood pressure, whereas antiseptic disruption raised it ([Tribble et al., 2019](https://pubmed.ncbi.nlm.nih.gov/30881924/)); trials isolating gentle mechanical scraping with blood-pressure endpoints could turn this into direct support.

* **Direction that could weaken the case:** Work showing that disturbing nitrate-reducing communities blunts the blood-pressure-lowering effect of dietary nitrate, and that restoring them recovers it ([Sanchez-Orozco et al., 2025](https://pubmed.ncbi.nlm.nih.gov/39788958/)), leaves open the possibility that overly thorough tongue cleaning could remove beneficial bacteria — a hypothesis that head-to-head studies of scraping intensity could confirm or refute.

## Conclusion

Tongue scraping is a simple, ancient, and inexpensive habit: drawing a small tool across the tongue each morning to remove the soft film of debris and bacteria that gathers there. Its best-supported effect is the one closest to the mechanism — it reliably clears that film, and with it the bacteria and leftover food that cause most everyday bad breath. Evidence that it freshens breath and modestly sharpens taste is reasonably consistent, though the studies are small and short, so these benefits are best described as real but not firmly established. Its possible role in blood-pressure and long-term health, through the tongue bacteria that help the body make a blood-vessel-relaxing molecule, is genuinely interesting but still unproven, and the evidence there points in more than one direction. The main downsides are minor and avoidable: gagging from reaching too far back and irritation from scraping too hard. Notably, the clearest concern for the beneficial bacteria comes from harsh antiseptic rinses, not from gentle physical cleaning. The overall evidence base is thin and shaped partly by commercial interest in chemical products over a low-cost tool, which argues for measured expectations. For someone focused on long-term health, tongue scraping stands out as a low-cost, low-risk practice whose modest, well-matched benefits do not require strong claims to justify attention.

**[Top](#top) - [Benefits](#expected-benefits) - [Risks](#potential-risks--side-effects) - [Protocol](#therapeutic-protocol)**