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Clascoterone for Hair Regrowth

Evidence Review created on 10/29/2026 using AI4L / Opus 5.5

Also known as: Cortexolone 17α-propionate, CB-03-01, Breezula, Winlevi

Motivation

Clascoterone is a prescription skin medicine that blocks the action of male hormones at the spot where it is applied. It is already sold as a cream for acne, and a stronger scalp solution has been developed for pattern hair loss, the gradual thinning at the crown and temples that affects most men as they age. Its appeal is that it acts in the scalp itself rather than lowering hormone levels throughout the body, as oral medications do.

Pattern hair loss is driven by a potent form of testosterone that slowly shrinks hair follicles in people who are genetically sensitive to it. For decades the main medical options have been a solution that stimulates follicles and oral medications that cut production of this hormone, the latter carrying concerns about sexual side effects. Clascoterone drew interest as the first new approach in more than thirty years, and its developer has run large trials in men to support an application to regulators.

This review examines whether clascoterone regrows scalp hair, how large and lasting any effect is, what long-term use on the scalp may risk, and how it fits beside existing options for health-focused adults prepared to commit to ongoing treatment.

Benefits - Risks - Protocol - Conclusion

Expert commentary on clascoterone, or on how male hormones acting on the follicle’s androgen receptor (the cell protein they bind to) drive androgenetic alopecia (pattern hair loss), the process clascoterone targets.

  • CB-03-01 (Breezula): Results, Side Effects, & Sourcing Options - Sarah King

    Walks through clascoterone’s laboratory work in dermal papilla cells (the follicle’s signalling cells) and its phase 2 hair trials, flagging which results were never published, from a hair-loss research site unaffiliated with the developer.

  • The Science of Healthy Hair, Hair Loss and How to Regrow Hair - Andrew Huberman

    Explains how dihydrotestosterone acting on the follicle’s androgen receptor, the receptor clascoterone blocks, drives pattern loss, and compares finasteride, dutasteride and minoxidil; clascoterone itself is not discussed.

  • #316 – AMA #63: A guide for hair loss: causes, treatments, transplants, and sex-specific considerations - Peter Attia

    Covers genetic sensitivity to dihydrotestosterone at the follicle androgen receptor, which clascoterone blocks, and the trade-offs of finasteride, minoxidil and procedures for long-term planning; clascoterone itself is not covered.

  • Hair Loss - Maureen Williams & Shayna Sandhaus

    A detailed health protocol explaining how dihydrotestosterone acting on follicle androgen receptors, the receptor clascoterone blocks, and androgen-receptor gene variants drive pattern loss, and reviewing minoxidil, oral and topical finasteride; clascoterone itself is not covered.

  • Evidence-Based Treatments for Pattern Hair Loss - Rhonda Patrick

    Rhonda Patrick and Derek of More Plates More Dates explain the androgen-driven follicle miniaturization that clascoterone’s receptor blockade targets, and weigh finasteride, dutasteride, minoxidil, microneedling and ketoconazole; clascoterone itself is not discussed.

No relevant content was found from Chris Kresser or Lifespan.io: web and on-site searches returned nothing on clascoterone or on androgen-driven pattern hair loss. The FoundMyFitness, Huberman, Attia and Life Extension items are included for the shared mechanism, not for clascoterone itself.

Grokipedia

Clascoterone

An AI-written overview of clascoterone’s pharmacology, acne approval and regulatory history, with a research subsection on the hair-loss trials; useful for orientation, though claims need checking against primary sources.

Examine

No Examine article on clascoterone exists. Examine.com does not typically cover prescription medications.

ConsumerLab

No ConsumerLab article on clascoterone exists. ConsumerLab does not typically cover prescription medications.

Systematic Reviews

These systematic reviews and meta-analyses all concern clascoterone 1% cream for acne, the only use for which pooled analyses exist.

No systematic review or meta-analysis covers clascoterone for hair regrowth, so the claimed effect is unrepresented; the pooled safety data above come from facial acne use of the cream, not the scalp solution.

Mechanism of Action

Clascoterone is a steroid ester that competes with dihydrotestosterone (DHT, the potent testosterone derivative that miniaturizes genetically sensitive follicles) for the androgen receptor in follicle cells (Rosette 2019, a laboratory study authored by the developer, Cassiopea). Unlike 5-alpha-reductase inhibitors (drugs that block conversion of testosterone to DHT), it leaves DHT levels unchanged and blocks the hormone’s target instead.

  • Selectivity: in animals it acted strongly on skin but showed no antiandrogenic (male-hormone-blocking) effect when injected (Celasco 2004); cleavage by esterases (enzymes that split ester bonds) to cortexolone is the proposed but unconfirmed explanation.
  • Absorption and distribution: the facial cream yields low blood levels with 84–89% protein binding, per the U.S. Food and Drug Administration (FDA label); the scalp solution produces measurable blood levels that accumulate (Täubel 2021).
  • Half-life and metabolism: no formal half-life is published. Liver cells yield cortexolone and conjugates; in vitro it neither inhibited cytochrome P450 (CYP) enzymes (the liver enzymes clearing most drugs) nor induced the three tested (FDA label).
  • Hormonal side pathway: cortexolone (11-deoxycortisol) is a cortisol precursor, the proposed basis for reversible suppression of the hypothalamic-pituitary-adrenal (HPA) axis (the brain-adrenal system that regulates cortisol).

A competing view holds that DHT sensitivity explains only part of pattern loss, with chronic inflammation and fibrosis (scarring of follicle tissue) also limiting recovery (English 2018, a hypothesis paper); receptor blockade alone might then slow loss more than restore hair. In cultured dermal papilla cells, clascoterone also reduced DHT-induced interleukin-6 (an inflammatory signal that inhibits hair growth) (Rosette 2019).

Historical Context & Evolution

Clascoterone (cortexolone 17α-propionate) was created by the Italian company Cosmo in the early 2000s as a topical antiandrogen (a drug that blocks male-hormone action) meant to work in skin without the body-wide effects of oral antiandrogens such as cyproterone acetate or flutamide; early animal work reported strong local but no systemic activity (Celasco 2004). Its original intended uses were acne and androgenetic alopecia, both driven by androgen action in the pilosebaceous unit (the hair follicle and its oil gland).

Acne advanced first: a pilot trial (Trifu 2011) and two phase 3 trials (Hebert 2020) led to U.S. approval of the 1% cream in 2020 (FDA label) and authorization by the European Medicines Agency (EMA) in October 2025 (EMA EPAR, its public assessment report).

The hair program ran in parallel. A 95-man U.S. proof-of-concept trial against minoxidil (NCT02279823) finished in 2016 without posted results, and a 404-man German dose-ranging trial reported hair-count gains at 12 months (EudraCT 2016-003733-23). The SCALP 1 and SCALP 2 phase 3 trials followed, with results released by press release in December 2025 (Cosmo topline release) and April 2026 (Cosmo 12-month release).

Interest among health-focused men stems from the trade-off with finasteride, whose sexual side effects deter many users; a scalp-limited blocker promised to sidestep that concern. What changed recently is the scale of the trial program, not its independence: the absolute size of regrowth remains unpublished, because the phase 3 data have so far appeared only as relative figures without peer review.

Expected Benefits

High 🟩 🟩 🟩

No benefit reaches High: every controlled hair trial and both acne phase 3 trials come from a single sponsor’s program (Cassiopea/Cosmo), not from independent research groups.

Medium 🟩 🟩

Increased Scalp Hair Count in Pattern Hair Loss ⚠️ Conflicted

Twice-daily clascoterone solution raised non-vellus (thick, pigmented) hair counts above vehicle (the same solution without drug) in men with moderate crown and temple loss, in a 404-man, 12-month dose-ranging trial (EudraCT 2016-003733-23) and two phase 3 trials of 1,465 men reported by press release (Cosmo topline release); a review summarizes them (Agrawal 2026). In a 293-woman trial, neither strength beat vehicle (EudraCT 2019-000950-78). Men’s self-ratings were inconsistent. Net: counts rise in men but not in women, and perceived benefit is less certain.

Magnitude: At 12 months, 5% twice daily gave 13.8 more non-vellus hairs in the target area than vehicle (95% CI, the confidence interval likely to contain the true effect, 5.9 to 21.6), among men who completed per plan (EudraCT 2016-003733-23). Phase 3 reported only relative gains of 539% and 168% over vehicle at 6 months (Cosmo topline release), and, among 6-month responders re-randomized in the extension, a 2.39-fold greater gain at 12 months with continued use than after switching to vehicle (Cosmo 12-month release). In women at 6 months, counts changed by +7.1 (5%) and +2.8 (7.5%) versus +9.1 with vehicle, not compared between groups (EudraCT 2019-000950-78).

Fewer Acne Lesions ⭕️ Not Central to Hair Regrowth

The 1% cream, a different formulation from the scalp solution, improved moderate to severe facial acne in two sponsor-run phase 3 trials of 1,440 patients (Hebert 2020), a result confirmed in pooled analysis (Alkhodaidi 2021). This bears on acne, not on scalp hair; it matters for people who have both conditions and apply the cream to the face.

Magnitude: Treatment success (clear or almost clear skin) in 18.4% versus 9.0% and 20.3% versus 6.5% with vehicle at 12 weeks (Hebert 2020); pooled relative risk (RR, how many times more likely success was) 2.87 (95% CI 2.11 to 3.89) (Alkhodaidi 2021).

Low 🟩

No benefit is graded Low: apart from the controlled trials above, there are no case series, observational studies or indirect human hair data for clascoterone.

Speculative 🟨

Added Regrowth With Minoxidil or Finasteride

Clascoterone blocks the receptor, finasteride lowers DHT and minoxidil stimulates follicles by another route, so effects could add. No controlled study has tested any combination; the basis is mechanistic only.

Benefit-Modifying Factors

  • Genetic polymorphisms: Variants in the androgen receptor gene on the X chromosome (such as shorter CAG repeats, a repeated DNA segment, which raise receptor activity) increase pattern-loss risk; whether they predict response to clascoterone has not been tested.
  • Baseline severity: Trials enrolled men at Norwood-Hamilton stages III-vertex to V (a seven-stage male hair-loss scale) (NCT05910450); results do not extend to stages VI–VII, where few follicles remain to rescue.
  • Baseline hormone levels: No study has related serum testosterone or DHT to response. Men using testosterone or anabolic steroids were excluded from phase 3 (NCT05910450); their higher androgen load could compete with the blocker.
  • Sex: Counts rose in the male trials, but in a 293-woman trial neither 5% nor 7.5% beat vehicle at 6 months (EudraCT 2019-000950-78); benefit in women is unproven.
  • Pre-existing scalp disease: Seborrheic dermatitis (a flaky, inflamed scalp condition), psoriasis and folliculitis (follicle inflammation) were exclusion criteria (NCT05910450); untreated scalp inflammation may weaken response and add irritation.
  • Other causes of shedding: Iron or protein deficiency and telogen effluvium (stress-triggered diffuse shedding) were excluded from phase 3 (NCT05910450); left uncorrected, they can mask any benefit.
  • Age: The dose-ranging trial enrolled men aged 18–55, mean about 40 (EudraCT 2016-003733-23); age-specific phase 3 results are unpublished. Older men with long-standing miniaturization may have fewer recoverable follicles.

Potential Risks & Side Effects

High 🟥 🟥 🟥

No risk reaches High: no adverse effect of clascoterone has been replicated in trials from more than one independent research group.

Medium 🟥 🟥

No risk reaches Medium: the controlled scalp-solution trials found no adverse event above vehicle, and the label-listed harms come from the facial cream, which is indirect evidence for the scalp solution.

Low 🟥

Hypothalamic-Pituitary-Adrenal Axis Suppression

Cortexolone, clascoterone’s breakdown product, is a cortisol precursor, and the cream label warns of reversible HPA-axis suppression under heavy use (FDA label; Bhatia 2024). Evidence is indirect: it comes from the 1% facial cream, while the 5% scalp solution delivers a larger dose that accumulates (Täubel 2021).

Magnitude: 5 of 69 participants had an abnormal cosyntropin (adrenal stimulation) test after 14 days of maximal-use cream, all normal about 4 weeks later; open-label study, no control group (Bhatia 2024).

Elevated Blood Potassium ⚠️ Conflicted

The cream label lists hyperkalemia (high blood potassium, which can disturb heart rhythm) (FDA label), which is indirect evidence for the scalp solution. Rates were near vehicle and did not track drug concentration in a sponsor-authored analysis (Del Rosso 2023). Net: a laboratory signal of uncertain clinical relevance.

Magnitude: Shifts to above-normal potassium in about 5% of clascoterone-treated versus about 4% of vehicle-treated participants in the cream trials (Del Rosso 2023).

Application-Site Reactions ⚠️ Conflicted

The cream label lists redness, itching, scaling, burning and stretch marks (striae) where applied (FDA label); acne trials found mostly trace or mild reactions (Hebert 2020). In the 5% scalp trial, itching and dermatitis (skin inflammation) were no more frequent than with vehicle. Net: reactions occur but appear largely vehicle-related.

Magnitude: Application-site itching in 3.8% (5% solution) versus 6.1% (vehicle), and application-site dermatitis in 3.8% versus 4.9%, over 12 months (EudraCT 2016-003733-23).

Sexual and Systemic Antiandrogen Effects ⚠️ Conflicted

Oral androgen blockers can lower libido and cause breast enlargement (gynecomastia). The scalp solution reaches measurable, accumulating blood levels (Täubel 2021), yet an investigator reports no sexual side effects in phase 3 (Healio December 2025). Net: no signal so far, on incomplete reporting.

Magnitude: Not quantified in available studies. The phase 3 safety tables are unpublished, and the dose-ranging trial’s posted results list no sexual adverse event above their 5% reporting threshold (EudraCT 2016-003733-23).

Menstrual and Ovarian Effects in Women

The cream label lists amenorrhea (absent periods) and polycystic ovaries (multiple small ovarian cysts) (FDA label), and U.S. spontaneous reports show a reproductive-system signal (Tao 2026). Evidence is indirect: these come from the cream; the 293-woman scalp-solution trial posted one serious heavy menstrual bleeding, judged unrelated (EudraCT 2019-000950-78).

Magnitude: Reproductive and breast disorders were reported disproportionately often (reporting odds ratio, a measure of over-reporting relative to other drugs, 1.88; 95% CI 1.25 to 2.83); spontaneous reports, no control group (Tao 2026).

Speculative 🟨

Fetal Harm From Exposure in Pregnancy

Clascoterone caused malformations in rat embryo studies (FDA label), and the EU bars use in pregnancy (EMA EPAR). The basis is animal data only; transfer from a treated scalp to a pregnant partner is theoretical.

Risk-Modifying Factors

  • Genetic polymorphisms: No pharmacogenetic variant is known to alter clascoterone handling; its esterase breakdown has no recognized common functional variant, and CYP genotype is unstudied; the label reports no CYP inhibition or induction but does not characterize its own CYP metabolism (FDA label).
  • Baseline potassium and kidney function: Shifts to high potassium occurred in about 5% on the cream (Del Rosso 2023); reduced kidney function or high-normal baseline potassium leaves less margin.
  • Baseline adrenal function: Low cortisol reserve or recent corticosteroid use may add to HPA suppression, inferred from the label warning (FDA label).
  • Sex: Women carry the label-listed menstrual and ovarian risks and pregnancy-related fetal risk; men carry the theoretical sexual effects.
  • Applied area, dose and duration: Larger areas, occlusion (covering treated skin, as with a hat or wrap) and prolonged use raise absorption (FDA label; Täubel 2021).
  • Pre-existing scalp disease: Broken, eczematous or sunburned skin absorbs and irritates more; the label advises against applying to such skin (FDA label).
  • Age: Children may be more susceptible to systemic toxicity (FDA label); adults over 65 were barely studied, and age-related skin thinning may raise absorption (inferred).

Key Interactions & Contraindications

Documented interactions:

  • CYP-metabolized drugs (warfarin, atorvastatin, sertraline): No clinically meaningful effect expected; in vitro, clascoterone did not inhibit CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1 or 3A4 at relevant concentrations, nor induce CYP1A2, 2B6 or 3A4 (FDA label). No dose change needed.
  • Occlusion, large areas and prolonged use: Raise systemic absorption and HPA-suppression risk (FDA label); application limited to the balding area, left uncovered until dry, reduces this.
  • Irritating topical products (medicated or abrasive cleansers, high-alcohol tonics, astringents): Additive local irritation (FDA label); the label calls for limiting concurrent use.
  • Topical adapalene (facial use): No interaction found; an open-label study combining it with the cream reported trace local reactions and no adverse events (Kircik 2026).
  • Topical clindamycin/benzoyl peroxide (facial use): No interaction found; a 9-patient open-label study combining the gel with the cream reported no adverse events (Kircik 2026).
  • Oral isotretinoin: No added harm found; a retrospective study of 82 patients with severe acne reported no worsening of adverse effects, including skin dryness, when the cream was added (Choi 2025).

Theoretical interactions (inferred from mechanism, not studied in humans):

  • Corticosteroids, topical or systemic (hydrocortisone, clobetasol scalp solution, prednisone): Additive HPA-axis suppression, inferred from cortexolone’s cortisol-pathway activity; cortisol testing with sustained co-use.
  • Potassium-raising drugs (spironolactone, ACE inhibitors such as lisinopril, angiotensin receptor blockers such as losartan, trimethoprim): Additive potassium elevation (ACE inhibitors and angiotensin receptor blockers are blood-pressure drugs that curb the hormone angiotensin), inferred from label potassium shifts; potassium check after starting either.
  • Other androgen blockers (finasteride, dutasteride, bicalutamide, cyproterone acetate): Additive androgen blockade, possibly adding regrowth but also sexual or breast effects, inferred from shared target; libido and breast tenderness tracked.
  • Topical minoxidil (over the counter): Its propylene glycol and alcohol vehicle may increase scalp penetration and irritation, inferred from vehicle chemistry; applying at separate times limits overlap.
  • Potassium supplements and potassium-based salt substitutes: Additive potassium load, inferred from label potassium shifts; potassium checked with regular high intake.
  • Saw palmetto, pumpkin seed oil and other supplements marketed as DHT blockers: Additive antiandrogenic activity, inferred from their proposed 5-alpha-reductase inhibition; sexual effects tracked if combined.
  • Testosterone therapy or anabolic steroids: Higher androgen levels compete with clascoterone at the receptor, inferred from competitive binding, which may blunt benefit; these users were excluded from phase 3 (NCT05910450).

Populations who should avoid Clascoterone:

  • Pregnancy, or possible pregnancy without contraception: EU contraindication, with contraception during treatment and for at least 10 days after stopping (EMA EPAR); rat malformations from 8 times the maximum recommended human dose (FDA label).
  • Children under 12 years: Safety not established, with possibly greater susceptibility to systemic toxicity (FDA label).
  • Damaged scalp (cuts, abrasions, eczema, sunburn): The label advises against application to such skin (FDA label).
  • Adrenal insufficiency (inadequate cortisol production) or long-term corticosteroid use: Inferred from the label’s HPA-suppression warning; no human data in this group.
  • Hyperkalemia or advanced chronic kidney disease: Inferred from label potassium shifts; no human data in this group.
  • Breastfeeding: No data on transfer into milk; the label calls for weighing benefit against risk to the infant (FDA label).

Risk Mitigation Strategies

Doses and timings below follow common practice unless cited.

  • Trial dose and area: 1.5 mL of 5% solution twice daily to the vertex and temples only (NCT05910450); larger areas or extra doses raise absorption and HPA-suppression risk.
  • No occlusion while wet: Letting the solution dry for about 30 minutes before hats, wraps or pillows limits absorption, which occlusion increases (FDA label); also reduces transfer to others.
  • Potassium checks: Serum potassium at baseline and after 4–8 weeks, sooner with potassium-raising drugs; a value above the laboratory’s upper limit prompts review. Mitigates hyperkalemia.
  • Adrenal testing when at risk: With unexplained fatigue, dizziness or corticosteroid co-use, a cosyntropin test showing cortisol of 18 µg/dL or less at 30 minutes indicates suppression, and withdrawal is the labeled response (FDA label).
  • Irritation management: Itching, burning or redness prompts reduced frequency or stopping (FDA label); treating seborrheic dermatitis first lowers application-site reactions.
  • Pregnancy safeguards: Women able to conceive use contraception during use and for 10 days after (EMA EPAR); treated men keep the scalp from contact with a pregnant partner until dry. Mitigates fetal harm.
  • Sexual-function tracking: Recording libido, erectile function and breast tenderness at baseline and every 3 months detects systemic antiandrogen effects early.
  • Menstrual tracking: Women using clascoterone off-label record cycles; new amenorrhea prompts stopping and evaluation. Mitigates menstrual and ovarian effects.
  • Verified product only: Licensed prescription channels avoid unregulated powders and solutions of unknown strength and purity, which risk overdosing and contamination.

Therapeutic Protocol

Doses are cited to their source; other parameters without a citation (timing, application technique, combinations) reflect common practice.

  • Phase 3 regimen: 1.5 mL of 5% solution twice daily to the balding vertex and temples, the SCALP 1 and 2 dose (NCT05910450; NCT05914805).
  • Dose-ranging alternatives: 1 mL of 2.5%, 5% or 7.5% twice daily, or 7.5% once daily; 5% and 7.5% twice daily gave the largest gains (EudraCT 2016-003733-23).
  • Off-label cream: Winlevi 1% is labeled at about 1 g twice daily for acne (FDA label); scalp use for hair is untested and one-fifth the trial concentration.
  • Competing approaches: Finasteride, minoxidil, low-level light and procedures are the established options (Attia AMA #63); investigator Maria Hordinsky expects clascoterone to be used alone or combined with them (Healio April 2026).
  • Popularized by: The developer, Cosmo Pharmaceuticals, through the SCALP program, with Hordinsky (University of Minnesota) as its most public investigator (Cosmo 12-month release).
  • Time of day: Morning and evening, at least 8 hours apart, as specified for the cream (EMA EPAR), onto a dry scalp.
  • Half-life: No formal half-life is published; with repeated high-dose application, blood levels plateau and fall to near zero about 2 days after the last dose (Täubel 2021).
  • Single versus split dosing: Split twice-daily dosing is standard; 7.5% once daily gained 12.7 hairs over vehicle versus 14.3 twice daily (EudraCT 2016-003733-23).
  • Genetic factors: No genotype guides dose; androgen receptor gene variants predict pattern-loss risk, not clascoterone response.
  • Sex: The phase 3 dose was set in men; 5% and 7.5% twice daily were tested in women without benefit over vehicle (EudraCT 2019-000950-78), and the EU bars use in pregnancy (EMA EPAR).
  • Age: Tested from 18 years, up to 55 in phase 2 (EudraCT 2016-003733-23) and without upper limit in phase 3 (NCT05910450); no age-based dose adjustment is described.
  • Baseline biomarkers: No biomarker predicts response; potassium and, where at risk, cortisol set a safety baseline.
  • Pre-existing conditions: Scalp inflammation was an exclusion criterion in phase 3 (NCT05910450); adrenal and kidney disease were not studied.

Discontinuation & Cycling

  • Long-term intent: Pattern hair loss is progressive, and clascoterone is designed for continuous use, like other pattern-loss drugs (Cosmo 12-month release).
  • Loss of gains after stopping: In the phase 3 extension, men switched to vehicle at month 6 lost part of their gains, while those who continued kept improving (Cosmo 12-month release).
  • Withdrawal effects: None reported; HPA suppression seen with the cream normalized within 4 weeks of stopping (FDA label).
  • Tapering: No tapering protocol exists or appears necessary; if HPA suppression develops, the label calls for withdrawal (FDA label).
  • Cycling: No evidence supports cycling; given the decline after switching to vehicle, off periods would be expected to forfeit gains.

Sourcing and Quality

  • No approved hair product (as of 10/29/2026): The 5% scalp solution is investigational; Cosmo plans a U.S. filing in early 2027 (Cosmo 12-month release).
  • Winlevi 1% cream: Distributed by Sun Pharmaceutical in the U.S. (FDA label) and held by Cassiopea in the EU (EMA EPAR); a cream base designed for facial skin, not hair-bearing scalp.
  • Unregulated powders and “research” solutions: Sold online without verified identity, concentration or purity; because clascoterone breaks down to cortexolone, poorly made solutions may lose potency.
  • Compounded preparations: No compounded scalp formulation has published stability, absorption or efficacy data; a licensed pharmacy with a certificate of analysis (laboratory proof of identity and strength) is the minimum standard.
  • Storage and shelf life: Winlevi is refrigerated before dispensing, kept at room temperature in use, and discarded 1 month after opening or 180 days after dispensing (FDA label).

Practical Considerations

  • Time to effect: Hair-count gains appeared from month 3 and continued to month 12 with ongoing use (Healio April 2026); a fair assessment takes 6–12 months.
  • Regulatory status: Approved only as Winlevi 1% cream for acne, in the U.S. since 2020 (FDA label) and the EU since 2025 (EMA EPAR); scalp use is off-label and the 5% solution is unapproved.
  • Reading the headline figures: The 539% and 168% figures are relative to vehicle, whose users lose hair over time; a small absolute gain can produce a large relative figure, and absolute phase 3 counts are not public.
  • Common pitfalls: Stopping after a few months, applying the acne cream to hair-bearing scalp, expecting regrowth on smooth bald skin, and buying unverified products.
  • Cost and access: Winlevi costs around $620 per 60 g tube for cash-paying customers (Drugs.com price guide); scalp-product pricing is unknown. Hair-loss drugs are usually self-paid, so the dominant financial interest lies with the manufacturer rather than insurers.
  • Conflict of interest: Every hair trial was sponsored by the developer, and the most quoted investigator has financial ties to it (Healio April 2026).

Interaction with Foundational Habits

  • Sleep: None known; no sleep effects have been reported, and clascoterone has no known action on the brain. Practically, applying the evening dose at least 30 minutes before lying down limits transfer to pillows and bed partners.
  • Nutrition: Indirect only; no food interaction applies to a scalp product. Iron, protein and calorie deficits cause shedding that can mask response, and phase 3 excluded such deficiencies (NCT05910450). Given label potassium shifts, potassium-based salt substitutes add to potassium load.
  • Exercise: None expected on muscle or training, as systemic androgen blockade is low. Practically, heavy sweating or swimming soon after application may wash solution off, so applying after the post-workout shower is common. Testosterone or anabolic steroid use may blunt benefit.
  • Stress management: Indirect: psychological stress can trigger telogen effluvium, confounding hair counts. Cortexolone’s effect on the HPA axis could blunt cortisol responses in rare cases (Bhatia 2024); unusual fatigue during stressful periods is a recognized indication for cortisol testing.

Monitoring Protocol & Defining Success

Before starting, a baseline record makes later judgement possible: standardized global scalp photographs with fixed angles and lighting, a hair count of a marked target area by phototrichogram (magnified photography of clipped hair) where available, and serum potassium. People with adrenal disease, corticosteroid use or wide application areas add a cosyntropin test or morning cortisol. Women add a pregnancy test and begin a menstrual record.

Ongoing monitoring follows this cadence: potassium at 4–8 weeks, then every 6–12 months; photographs and hair counts at 3, 6 and 12 months, then yearly; cortisol testing only with symptoms or added corticosteroids. Routine heart-rhythm testing is not part of this protocol, as a high-dose study found no effect on the QT interval (the heart’s electrical recovery time) (Täubel 2021). Success is a stable or rising target-area count and visible improvement at 12 months.

Biomarker Optimal Functional Range Why Measure It? Context/Notes
Serum potassium 3.5–5.0 mmol/L (standard reference range) Safety check: label lists hyperkalemia; high values change use Avoid hemolyzed samples (red-cell breakdown, falsely high); pair with creatinine, a kidney waste marker; shifts in about 5% on cream (Del Rosso 2023)
Cortisol 30 minutes after cosyntropin Above 18 µg/dL (FDA label cutoff for a normal response) Safety check: suppression prompts withdrawal Source: FDA label; conventional morning serum cortisol reference range about 5–25 µg/dL; draw morning cortisol 7–9 a.m.; cosyntropin is synthetic ACTH (adrenocorticotropic hormone, the pituitary signal for cortisol)
Target-area hair count No established target; track change from own baseline Expected to change: the trials’ primary endpoint Same marked area, clipped hair and device each time; vehicle-treated men lost about 9 hairs over 12 months (EudraCT 2016-003733-23)
Global scalp photographs No established target; compare with own baseline Expected to change: visible coverage Same lighting, hair length, parting and angles; at 3, 6 and 12 months

Qualitative markers:

  • Perceived density and scalp coverage, rated on a simple 7-point scale like the one used in trials
  • Shedding seen in the shower or on brushes
  • Scalp itching, burning, redness or flaking
  • Libido, erectile function and breast tenderness
  • Menstrual regularity in women
  • Unusual fatigue, dizziness or salt craving, possible signs of low cortisol

Emerging Research

  • No ongoing hair trial: A ClinicalTrials.gov search on 10/29/2026 found no recruiting or active clascoterone trial for hair loss; every registered hair trial is completed, so the evidence base will grow through publication and regulatory review rather than new trials.
  • SCALP 1 (NCT05910450), completed January 2026, no results posted: 703 men, phase 3, primary endpoints target-area hair count and self-rated coverage at 6 months. Published absolute counts near the phase 2 gain would firm up the Medium grade; small absolute gains would weaken it.
  • SCALP 2 (NCT05914805), completed July 2025, no results posted: 762 men, identical design. Publication of both trials’ self-rated outcomes would settle the conflict: consistent positive ratings would remove it, while null ratings would confine the benefit to measurable but barely noticed hair.
  • Minoxidil-comparison trial (NCT02279823), completed 2016, no results posted: 95 men received clascoterone 5%, minoxidil 5% or vehicle for 26 weeks. Results matching minoxidil would support use alone; inferior results would favor add-on use.
  • Regulatory review: A U.S. filing is planned for early 2027 (Cosmo 12-month release). FDA review documents would disclose blood levels and adrenal testing at the scalp dose; suppression findings would raise the HPA risk grade, clean data would lower concern.
  • Women and combinations: A 293-woman trial (EudraCT 2019-000950-78), completed April 2021 with posted results, found no hair-count gain over vehicle. No further female trial, or trial combining clascoterone with minoxidil or finasteride, is registered, so added benefit remains Speculative.
  • Competing topical androgen blockers: Pyrilutamide (KX-826) and the androgen-receptor degrader GT20029 are in development (Agrawal 2026); head-to-head data would show whether clascoterone’s effect is distinctive or shared across the class.

Conclusion

Clascoterone is a skin-applied blocker of male-hormone action, already sold as an acne cream and developed as a stronger scalp solution for pattern hair loss. For men who want to keep their hair without the body-wide hormone changes of oral medications, its appeal is the prospect of acting mainly where it is applied.

The evidence for regrowth is moderate. Controlled trials in men with mild to moderate loss found more hair in treated areas than with an inactive solution, and gains continued over a year with ongoing use but faded after stopping. All of these trials were run by the developer, the largest have been reported only through company announcements, and the absolute size of the gain is still not public. Men’s own sense of improvement was less consistent than the hair counts. A smaller trial in women found no gain over the inactive solution, and no data exist for use alongside existing hair-loss drugs.

The known risks are mostly carried over from the acne cream: skin irritation, a reversible dampening of the body’s stress-hormone system under heavy use, small rises in blood potassium, and menstrual changes in women. The scalp solution reaches measurable blood levels, so these risks may weigh more at hair-loss doses, although the hair trials have reported side effects similar to the inactive solution. Animal studies point to harm in pregnancy.

Overall, the picture is of a promising local option resting on a single company’s data, with key details not yet independently published.

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