---
canonical_name: Clascoterone
alternate_names: Cortexolone 17α-Propionate, CB-03-01, Breezula, Winlevi
canonical_topic: Clascoterone for Hair Regrowth
short_topic_lc: clascoterone_hair
creation_date: 2026-0703-0055
creator_ai_fullname: Opus 4.8
---
# Clascoterone for Hair Regrowth
Evidence Review created on 07/03/2026 using [AI4L](https://github.com/forever-healthy/AI4L) / Opus 4.8
**Also known as:** Cortexolone 17α-Propionate, CB-03-01, Breezula, Winlevi
## Motivation
Clascoterone is a topical drug that blocks androgens — the male-type hormones, chiefly dihydrotestosterone — directly at the skin and hair follicle. It was first approved in a low-strength cream for acne, and a stronger scalp solution (Breezula) is now in late-stage testing for pattern hair loss. Its appeal is a simple idea: interrupt the hormonal signal that shrinks hair follicles, but only where the solution is applied, so the rest of the body is largely spared.
Pattern hair loss affects a large share of men by midlife and many women as well, yet the medicines used for it have changed little in three decades. The oral drugs that lower androgen activity work throughout the body and carry sexual and hormonal concerns that lead many to avoid them. A treatment that acts at the follicle alone would be a meaningful shift, and recent large trials reporting visible regrowth have drawn considerable attention.
This review examines what is known about clascoterone applied to the scalp for hair regrowth: how it is thought to work, the strength and limits of the trial evidence, its safety signals, how it is used, and where it stands relative to established options.
**[Benefits](#expected-benefits) - [Risks](#potential-risks--side-effects) - [Protocol](#therapeutic-protocol) - [Conclusion](#conclusion)**
## Recommended Reading
This section lists high-level expert commentary and overview content that discusses clascoterone for hair loss by name.
* [AMA #63: A guide for hair loss: causes, treatments, transplants, and sex-specific considerations](https://peterattiamd.com/ama63/) - Peter Attia
A physician-led deep dive into pattern hair loss that frames how androgen sensitivity drives follicle miniaturization and walks through the current treatment landscape, providing the clinical context in which a topical androgen blocker like clascoterone would sit.
* [Clascoterone: A Topical Anti-Androgen For Hair Loss?](https://www.baumanmedical.com/clascoterone-topical-anti-androgen-for-hair-loss/) - Alan Bauman
A hair-restoration specialist's overview of clascoterone's mechanism and development status, useful for understanding why a locally acting androgen blocker is viewed as a potential alternative to systemic finasteride.
* [What Is Breezula® (Clascoterone)?](https://xyonhealth.com/blogs/library/what-is-breezula%C2%AE-clascoterone) - Lily Cai
A clinician-reviewed summary of the available clinical evidence for the scalp solution, comparing it against finasteride and setting expectations on efficacy and the systemic-sparing rationale.
* [Topical Clascoterone for Hair Loss: A Promising New Anti-Androgen Therapy](https://sons.co.uk/blogs/journal/topical-clascoterone-for-hair-loss-a-promising-new-anti-androgen-therapy) - Sons
A concise, clinician-reviewed explainer of how clascoterone 5% works and what the recent Phase 3 trial read-outs mean, written for a general reader considering the treatment.
* [Clascoterone, an upcoming topical antiandrogen for acne and hair loss treatment without systemic effects](https://genderanalysis.net/2020/07/clascoterone-an-upcoming-topical-antiandrogen-for-acne-and-hair-loss-treatment-without-systemic-effects/) - Zinnia Jones
An early, detailed lay analysis of clascoterone's pharmacology that emphasizes its local action and negligible systemic absorption, valuable for understanding the "antiandrogen without systemic effects" positioning.
_Note: Of the five priority experts, only Peter Attia had directly relevant, on-topic hair-loss content covering the drug class and treatment landscape. Rhonda Patrick, Andrew Huberman, Chris Kresser, and Life Extension Magazine returned no clascoterone-specific material on either web search or on-site search, so the remaining four items are high-quality clinician-authored overviews that discuss the drug by name._
## Grokipedia
* [Clascoterone](https://grokipedia.com/page/Clascoterone)
A dedicated, fact-checked encyclopedia entry covering clascoterone's mechanism as a topical androgen receptor inhibitor, its acne approval and chemistry, and its research in pattern hair loss, useful as a broad reference frame for how the drug sits across both indications.
## Examine
No Examine article exists for clascoterone. Examine.com focuses on dietary supplements and nutrition, and does not typically cover prescription medications such as this topical androgen receptor inhibitor.
## ConsumerLab
No ConsumerLab article exists for clascoterone. ConsumerLab.com reviews dietary supplements and consumer health products, and does not typically cover prescription medications such as this topical androgen receptor inhibitor.
## Systematic Reviews
A real-time PubMed search was performed for clascoterone with "systematic review OR meta-analysis". All identified systematic reviews and meta-analyses concern clascoterone for acne vulgaris; none evaluate its use for hair regrowth.
* [Efficacy and safety of topical clascoterone cream for treatment of acne vulgaris: A systematic review and meta-analysis of randomized placebo-controlled trials](https://pubmed.ncbi.nlm.nih.gov/33258536/) - Alkhodaidi et al., 2021
This pooled analysis of the pivotal placebo-controlled acne trials establishes clascoterone's efficacy signal and its notably clean local and systemic tolerability as a topical androgen receptor inhibitor, the same molecule and mechanism now being applied to the scalp.
* [The efficacy of Topical Clascoterone versus systematic spironolactone for treatment of acne vulgaris: A systematic review and network meta-analysis](https://pubmed.ncbi.nlm.nih.gov/38814916/) - Basendwh et al., 2024
A network meta-analysis comparing topical clascoterone against oral spironolactone, useful here for the broader question of whether a locally applied androgen blocker can rival systemic antiandrogens without their body-wide effects.
## Mechanism of Action
Clascoterone (cortexolone 17α-propionate) is an androgen receptor inhibitor. Pattern hair loss is driven by dihydrotestosterone (DHT, the most potent male-type hormone in the skin), which binds androgen receptors inside the hair follicle's dermal papilla and progressively shrinks — or "miniaturizes" — the follicle. Each hair cycle produces a thinner, shorter hair, and the growth (anagen) phase shortens until pigmented terminal hairs become fine, near-invisible vellus hairs.
Clascoterone competes with DHT for the same androgen receptor at the follicle. By occupying the receptor without triggering the full miniaturizing signal, it is thought to blunt the hormonal drive behind follicle shrinkage locally, at the point of application. This differs mechanistically from finasteride and dutasteride, which are 5-alpha-reductase inhibitors (they block the enzyme that converts testosterone to DHT and thereby lower DHT levels rather than blocking its receptor), and from minoxidil, whose growth-promoting action is largely independent of the androgen pathway.
An important open question is how much of the follicular benefit is receptor blockade versus other effects. Clascoterone also reduces sebaceous gland activity and locally modulates inflammatory signaling in skin, and in laboratory work it has been reported to influence growth-factor signaling in dermal papilla cells. Whether these ancillary actions contribute meaningfully to regrowth, beyond androgen receptor blockade, has not been fully resolved.
Key pharmacological properties: clascoterone is applied topically and is designed for minimal systemic exposure. When absorbed, it is rapidly metabolized — its principal metabolite is cortexolone (also called 11-deoxycortisol) — and plasma concentrations of the parent drug are low and transient. Its structural similarity to cortisol precursors underlies a theoretical concern about the body's stress-hormone axis at high exposure, addressed under Risks. Because delivery is local and metabolism is rapid, systemic half-life is short and tissue distribution is dominated by the treated skin rather than distant organs; it is not primarily cleared through the major drug-metabolizing liver enzymes (such as CYP3A4, a common liver enzyme that processes many drugs) at the low systemic levels achieved.
## Historical Context & Evolution
Clascoterone began as CB-03-01, a molecule developed by Cosmo Pharmaceuticals and its spin-out Cassiopea as a topical antiandrogen for androgen-driven skin conditions. Its original and first-approved use was acne: in August 2020 the U.S. Food and Drug Administration (FDA) approved clascoterone 1% cream (brand name Winlevi) for acne vulgaris in patients 12 and older — the first genuinely new mechanism approved for topical acne in decades.
The rationale for extending it to hair loss followed directly from its mechanism. Because acne and pattern hair loss share a dependence on androgen signaling in the skin — sebaceous glands in acne, dermal papilla in hair loss — a drug that blocks the androgen receptor locally was a natural candidate for both. Developers pursued a higher-concentration scalp solution (5%, under the name Breezula) specifically for androgenetic alopecia, reasoning that a receptor blocker acting only at the scalp could deliver antiandrogen benefit without the systemic sexual and hormonal effects that limit oral options.
The evidence evolved in stages. An early Phase 2 solution study in men with pattern hair loss compared clascoterone against minoxidil and vehicle and supported further development. This was followed by a large Phase 3 program — the two SCALP pivotal trials — whose top-line results reported in late 2025 showed significant improvements in measured hair count versus vehicle. Scientific opinion on clascoterone for hair loss remains provisional rather than settled: enthusiasm rests heavily on recently announced trial data that, at the time of writing, are known largely through top-line disclosures and conference presentations from the developer (Cosmo Pharmaceuticals and its spin-out Cassiopea) rather than full peer-reviewed publication, and the drug is not yet approved for this use. This is a relevant conflict of interest — the manufacturer has a direct financial stake in a favorable read-out and controls both the framing and the timing of what has been released so far — and it means the reported magnitude should be treated as a company-sourced claim awaiting independent confirmation. What has clearly changed is the plausibility that a purely topical androgen receptor blocker can produce meaningful regrowth; what remains open is the durability, magnitude relative to existing drugs, and independent confirmation of those results.
## Expected Benefits
### High 🟩 🟩 🟩
_No benefit is graded High. The pivotal Phase 3 hair-regrowth data are recent and, at the creation date, are known mainly through top-line disclosures rather than full peer-reviewed publication, so no benefit yet meets the bar for High-quality, independently confirmed evidence._
### Medium 🟩 🟩
#### Increased Scalp Hair Count in Male Pattern Hair Loss
The core benefit is measurable regrowth: more hairs per unit area of balding scalp. This is quantified as Total (or Target) Area Hair Count, a standardized photographic count of hairs in a defined scalp zone. Two large Phase 3 vehicle-controlled trials (SCALP1 and SCALP2, together roughly 1,465 men) using clascoterone 5% solution twice daily reported statistically significant improvements in non-vellus hair count versus vehicle at 6 months. The mechanism — local androgen receptor blockade reducing follicle miniaturization — is coherent with the pathophysiology. The evidence is graded Medium rather than High because the pivotal results are, at present, largely top-line and not yet fully peer-reviewed, and long-term maintenance data are still emerging.
**Magnitude:** Company-reported top-line Phase 3 data described large relative improvements in target-area hair count versus vehicle (on the order of a roughly 1.7-fold improvement in one trial and a substantially larger relative figure in the other); absolute hair-count gains per defined scalp area have not yet been fully published.
### Low 🟩
#### Comparable or Favorable Local Tolerability Versus Existing Topicals
Beyond raw counts, a practical benefit is that regrowth is achieved with a locally applied agent that has, across its acne and alopecia programs, shown low rates of skin irritation and minimal systemic hormonal signal. For people who cannot tolerate topical minoxidil (e.g., scalp irritation, unwanted facial hair) or who wish to avoid systemic antiandrogens, a well-tolerated topical alternative is itself a meaningful advantage. Evidence is Low because head-to-head tolerability comparisons specific to the scalp solution are limited and drawn partly from the acne formulation.
**Magnitude:** In the pivotal acne program, treatment-related local skin reactions were generally mild and uncommon; scalp-solution safety was reported as favorable, but precise comparative irritation rates versus minoxidil are not yet published.
#### Systemic-Sparing Androgen Blockade
A distinguishing benefit is antiandrogen action largely confined to the scalp. Because clascoterone is applied topically, is rapidly metabolized, and reaches only low, transient blood levels, it offers the follicle-level benefit of blocking androgen signaling without the body-wide hormonal exposure of oral finasteride, dutasteride, or spironolactone. This matters most for the target audience member who wants to protect hair but is unwilling to accept systemic sexual or hormonal risk. Evidence is Low because "avoids systemic effects" is inferred from pharmacokinetic data and adverse-event profiles rather than from trials designed to measure the absence of systemic harm.
**Magnitude:** Systemic absorption of the parent drug is low and transient; the practical implication is negligible measured impact on serum DHT or testosterone, in contrast to the measurable systemic DHT suppression seen with oral 5-alpha-reductase inhibitors.
### Speculative 🟨
#### Benefit in Female Pattern Hair Loss
Because androgen signaling contributes to hair loss in at least some women, a topical androgen receptor blocker is a plausible candidate for female pattern hair loss, where systemic antiandrogens carry pregnancy and hormonal restrictions. However, the completed pivotal hair-loss trials enrolled only men, the role of androgens in female pattern hair loss is less clear-cut, and no controlled clascoterone data in women with hair loss exist. This benefit rests on mechanistic reasoning and extrapolation only.
#### Additive Effect When Combined With Minoxidil
Because clascoterone (androgen receptor blockade) and minoxidil (a growth stimulant acting through a largely separate pathway) work by different mechanisms, combining them could plausibly produce greater regrowth than either alone — a strategy analogous to combining finasteride with minoxidil. No controlled trial has yet tested clascoterone plus minoxidil for hair loss, so this remains mechanistic speculation.
## Benefit-Modifying Factors
* **Baseline severity and follicle viability:** Regrowth requires follicles that are miniaturized but still alive. The pivotal trials enrolled men with mild-to-moderate loss (roughly Norwood-Hamilton stage III-vertex to V). Someone with advanced, long-standing baldness and largely fibrosed follicles is likely to see less benefit, since a receptor blocker cannot regrow a follicle that no longer exists.
* **Sex-based differences:** All completed pivotal hair-loss evidence is in men. Because the contribution of androgens to female pattern hair loss is more variable, the magnitude of benefit in women is uncertain and cannot be assumed equal to that in men.
* **Age:** Younger individuals earlier in the miniaturization process tend to have more salvageable follicles across pattern hair loss treatments generally; those at the older end of the target range with more advanced miniaturization may respond less. Age-specific response data for clascoterone are not yet published.
* **Concurrent or prior hair-loss therapy:** Benefit is hardest to interpret in isolation for those already using minoxidil or a 5-alpha-reductase inhibitor. The trials excluded recent use of these agents; real-world benefit may differ when clascoterone is added to an existing regimen versus used alone.
* **Adherence to twice-daily application:** The regimen is a scalp solution applied twice daily. As with topical minoxidil, benefit depends on sustained, consistent application; inconsistent use is expected to blunt results.
* **Genetic androgen sensitivity:** Pattern hair loss reflects inherited sensitivity of follicles to DHT rather than uniformly high hormone levels. Individual variation in androgen receptor sensitivity may plausibly influence how much benefit receptor blockade delivers, though clascoterone-specific pharmacogenetic data are not available.
* **Baseline biomarkers (iron stores and starting hair count):** A low baseline iron store (ferritin) can independently limit hair regrowth and blunt the apparent benefit of any hair-loss treatment, so correcting deficiency before or alongside treatment supports a fairer measure of response; the pivotal trials excluded people with significant nutrient deficiencies. Baseline hair count in the target area also sets the ceiling for measurable gain — someone with a higher starting density of viable, miniaturized follicles has more capacity to demonstrate regrowth than someone whose target zone is already sparse.
## Potential Risks & Side Effects
### High 🟥 🟥 🟥
_No risk is graded High. No serious or common systemic harm has been established for clascoterone at either the approved acne strength or the investigational scalp strength; the consistently reported signal is mild, local, and low-frequency._
### Medium 🟥 🟥
#### Local Application-Site Reactions
The most consistent adverse effects are at the site of application: redness, dryness, scaling, itching, stinging, or irritation of the treated skin or scalp. These are generally mild, tend to appear early, and typically do not require stopping treatment. The mechanism is direct local exposure of skin to the solution and its vehicle (which, for a scalp solution, may include alcohol-based components that can dry the skin). This is the dominant real-world tolerability consideration.
**Magnitude:** In the acne program, treatment-emergent local reactions were mostly mild and affected a minority of users; scalp-solution local tolerability was reported as favorable, though exact incidence figures for the 5% solution are not yet fully published.
### Low 🟥
#### Theoretical Suppression of the Body's Stress-Hormone Axis (HPA Axis)
Because clascoterone is structurally related to cortisol precursors, regulators required testing of the hypothalamic-pituitary-adrenal axis (the HPA axis — the body's cortisol control system). In dedicated studies of the acne cream, transient, reversible reductions in the adrenal cortisol response were observed in some participants, resolving after stopping. At the low systemic exposure achieved with topical use this is considered a minor, reversible signal, but the larger surface area and higher concentration of a scalp solution warrants monitoring in the ongoing data. It is graded Low because clinically meaningful adrenal suppression has not been demonstrated in practice.
**Magnitude:** Reported HPA effects in acne studies were transient laboratory changes that reversed on discontinuation, with no associated clinical adrenal insufficiency.
#### Local Blood-Chemistry Shift (Elevated Potassium) Seen With the Acne Formulation
The clascoterone acne prescribing information notes that some patients showed local skin reactions and, in the dedicated HPA/pharmacokinetic study, isolated laboratory abnormalities including elevated potassium (hyperkalemia — higher-than-normal blood potassium, which can affect heart rhythm at high levels). These were infrequent and of uncertain clinical significance at topical exposures. Relevance to the scalp solution is unconfirmed. Graded Low given rarity and unclear clinical meaning.
**Magnitude:** Reported as infrequent, generally transient laboratory elevations in controlled study settings rather than a common clinical event.
### Speculative 🟨
#### Systemic Antiandrogen Effects With Overuse or Broken Skin
Clascoterone is engineered for minimal systemic absorption, but applying far more than directed, or applying to inflamed or broken scalp skin, could theoretically raise systemic exposure and, in principle, produce mild antiandrogen effects. No such systemic hormonal effects have been demonstrated at recommended use, so this remains a mechanistic caution rather than an observed harm.
#### Unknown Long-Term (Multi-Year) Safety of the Scalp Solution
Pattern hair loss treatment is typically continuous and open-ended, but controlled clascoterone scalp-solution data span months to about a year. Any rare or slowly emerging effect of years of twice-daily scalp application is simply not yet characterized. This is an absence-of-evidence concern rather than a known risk.
## Risk-Modifying Factors
* **Broken, inflamed, or diseased scalp skin:** Applying to scalp with active dermatitis, infection, psoriasis, or wounds can increase local irritation and theoretically increase absorption. The trials excluded such scalp conditions; treating intact, healthy skin lowers both local and systemic risk.
* **Pre-existing adrenal or electrolyte disorders:** Given the theoretical HPA-axis and potassium signals, individuals with known adrenal insufficiency or disorders of potassium handling may warrant extra caution and monitoring, even though clinically meaningful effects have not been shown at topical doses.
* **Genetic polymorphisms in cortisol and steroid metabolism:** No clascoterone-specific pharmacogenetic risk marker is established, but individuals with inherited variants affecting adrenal steroid handling — for example CYP21A2 (the gene encoding 21-hydroxylase, the enzyme that governs cortisol synthesis) as in non-classic congenital adrenal hyperplasia — could in principle be more sensitive to the theoretical HPA-axis signal; this is a mechanistic consideration only, as no such gene-by-drug interaction has been demonstrated at topical exposure.
* **Pregnancy and potential for pregnancy (sex-based):** As an antiandrogen, clascoterone is of theoretical concern for a developing male fetus. Although systemic absorption is minimal, this is a central consideration for any use in women of reproductive potential, and the completed pivotal trials enrolled only men.
* **Concurrent drugs affecting potassium or cortisol:** Someone already taking agents that raise potassium or suppress adrenal function might, in principle, be more sensitive to any small additive effect, though no clinically significant interaction has been established at topical exposure.
* **Age and skin integrity:** Older or more fragile skin, or heavily sun-damaged scalp skin, may be more prone to local irritation; this is a general topical-therapy consideration rather than a clascoterone-specific finding.
* **Overapplication behavior:** The main modifiable driver of systemic exposure is using more than the directed volume or frequency; adhering to the specified twice-daily volume keeps exposure — and therefore risk — low.
## Key Interactions & Contraindications
* **Prescription drugs:** No clinically significant prescription drug interactions have been established for topical clascoterone. Because systemic exposure is low, meaningful interactions with drugs cleared by the major liver enzymes (such as CYP3A4, a common drug-metabolizing enzyme) are not expected. **Severity: caution/monitor** — theoretical only.
* **Drugs that raise potassium (e.g., ACE inhibitors (angiotensin-converting enzyme inhibitors, blood-pressure drugs that also tend to raise potassium) such as lisinopril, angiotensin receptor blockers such as losartan, potassium-sparing diuretics such as spironolactone):** Given the isolated hyperkalemia (high blood potassium) signal seen in controlled clascoterone studies, combining with other potassium-raising drugs is a theoretical additive concern. **Severity: caution** — monitor potassium if there is baseline risk; clinical consequence would be elevated potassium affecting heart rhythm, but this has not been observed at topical use.
* **Over-the-counter medications:** No specific OTC drug interactions are established. Concurrent OTC scalp products that irritate skin (e.g., strong exfoliants, high-alcohol tonics) may worsen local irritation. **Severity: caution** — separate application or avoid overlapping irritants.
* **Supplement interactions:** No specific supplement interactions are documented. **Severity: caution** — theoretical only.
* **Supplements with additive (same-direction) effects:** Supplements marketed to block DHT or reduce androgen activity — for example saw palmetto, pumpkin seed oil, or other purported "DHT blockers" — act in the same antiandrogen direction and could be considered additive to clascoterone's mechanism, though no combined data exist and their own efficacy evidence is weak. **Severity: monitor** — no established harm, effect on outcomes unknown.
* **Other topical hair-loss interventions (minoxidil, topical finasteride):** Applying multiple scalp agents together can increase overall irritation and complicate assessment of which agent is working; combination has not been formally studied for clascoterone. **Severity: caution** — separate timing to reduce irritation; efficacy of combination is unproven.
* **Populations who should avoid or use only with specialist guidance:** Pregnant or breastfeeding women, and women of reproductive potential not using contraception (theoretical antiandrogen risk to a male fetus); individuals with active scalp skin disease at the application site; individuals with known adrenal insufficiency; and anyone with a hypersensitivity to clascoterone or the solution's components. Use in anyone under 18 for hair loss is outside the studied population. **Severity for pregnancy: treat as contraindicated pending data**, given the antiandrogen mechanism.
## Risk Mitigation Strategies
* **Apply only to intact, healthy scalp skin:** Avoid applying to areas with active dermatitis, sunburn, cuts, or infection. This mitigates both the dominant risk (local irritation) and the theoretical risk of increased systemic absorption through compromised skin.
* **Adhere to the directed volume and twice-daily frequency:** Use only the specified amount (in the pivotal trials, 1.5 mL twice daily) and resist the urge to overapply. This directly limits systemic exposure and the associated theoretical antiandrogen, HPA-axis, and potassium concerns.
* **Introduce alongside a gentle scalp-care routine:** Because the vehicle can be drying, pairing treatment with a mild, non-irritating shampoo and avoiding overlapping harsh scalp products (strong exfoliants, high-alcohol tonics) reduces the redness, dryness, and scaling that are the most common reasons people stop.
* **Screen for pregnancy and use contraception where relevant:** For any woman of reproductive potential considering use, confirm non-pregnancy and use effective contraception before starting, mitigating the theoretical antiandrogen risk to a developing male fetus.
* **Baseline and periodic checks for higher-risk users:** For individuals with adrenal disease or on potassium-raising drugs, checking baseline potassium and adrenal status and rechecking if symptoms arise mitigates the low-probability HPA-axis and hyperkalemia signals; routine monitoring is not required for healthy users given low systemic exposure.
* **Stop and reassess on significant local reaction:** If marked or persistent irritation develops, pausing treatment allows the skin to recover and prevents progression to a reaction severe enough to force permanent discontinuation; most local reactions are mild and reversible.
## Therapeutic Protocol
* **Standard regimen used in the pivotal program:** In the Phase 3 SCALP trials, clascoterone 5% solution was applied topically at 1.5 mL twice daily to the balding areas of the scalp (vertex and temples). This twice-daily topical scalp application is the protocol on which the reported efficacy rests; the drug is not yet approved for hair loss, so any clinical use ahead of approval is off-label and investigational.
* **Alternative and comparator approaches (presented without ranking):** The established topical is minoxidil (a growth stimulant); the established systemic options are the oral 5-alpha-reductase inhibitors finasteride and dutasteride and, in women, spironolactone. Clascoterone's distinguishing position is topical androgen receptor blockade — a different mechanism from minoxidil and a local alternative to systemic antiandrogens. Combination strategies (e.g., with minoxidil) are used routinely in practice for other agents but are not yet validated for clascoterone.
* **Who developed/popularized the approach:** The molecule and its scalp solution were developed by Cosmo Pharmaceuticals and Cassiopea; the pivotal SCALP program was run by that developer with academic dermatology investigators, and hair-restoration specialists (e.g., Alan Bauman) have been early public commentators.
* **Best time of day:** No specific time-of-day advantage is established; the studied regimen is simply twice daily, spaced across the day, applied to a dry scalp and allowed to dry before styling.
* **Expected half-life:** Systemic half-life of the parent drug is short — it is rapidly metabolized to cortexolone and reaches only low, transient blood levels — which is consistent with a twice-daily topical schedule to maintain local follicular exposure.
* **Single versus split dosing:** The regimen is inherently split (twice daily) rather than a single daily application, reflecting local pharmacokinetics and the goal of sustained receptor occupancy at the follicle.
* **Genetic considerations:** Pattern hair loss reflects inherited androgen sensitivity, but no pharmacogenetic testing (e.g., androgen receptor variants) is established to guide clascoterone dosing; dose is not individualized on genetic grounds.
* **Sex-based considerations:** The validated protocol is in men. Any use in women would be an extrapolation, with added attention to pregnancy precautions, and is not supported by completed controlled trials.
* **Age considerations:** Studied in adult men (18 and older). Response at the older end of the range may be limited by more advanced miniaturization; no separate geriatric dosing is defined.
* **Baseline biomarkers:** No biomarker is required to start; unlike systemic antiandrogens, there is no need to track serum DHT, and monitoring is primarily clinical (hair count/photographs).
* **Pre-existing conditions:** Active scalp skin disease should be treated first; adrenal or potassium disorders warrant caution as noted, but do not have a defined dose adjustment.
## Discontinuation & Cycling
* **Lifelong versus short-term:** Like other pattern hair loss treatments, benefit is expected to depend on continued use. Pattern hair loss is progressive, and a receptor blocker only holds the androgen signal in check while present, so treatment is best understood as ongoing rather than a finite course.
* **Loss of benefit after stopping:** Because clascoterone does not permanently alter the follicle's genetic androgen sensitivity, discontinuation is expected to allow miniaturization to resume, with gradual loss of the gained hair over subsequent cycles — analogous to what is seen when minoxidil or finasteride is stopped. Long-term off-treatment data specific to clascoterone are not yet available.
* **Withdrawal effects:** No pharmacological withdrawal syndrome is described; "withdrawal" here means the return of the underlying hair loss, not a drug-withdrawal reaction.
* **Tapering:** No taper is required for safety; the drug can simply be stopped. There is no evidence that tapering changes outcomes.
* **Cycling:** There is no rationale or evidence for cycling clascoterone to maintain efficacy; continuous use is the studied approach, and interrupting treatment would be expected to reduce, not preserve, benefit.
## Sourcing and Quality
* **Regulatory form and availability:** For hair loss, clascoterone 5% solution (Breezula) is investigational and not yet marketed as of the creation date; obtaining it for this use before approval is not straightforward. The only currently marketed clascoterone product is the 1% acne cream (Winlevi), which is a different formulation and strength and is not the studied hair-loss product.
* **Avoiding unregulated substitutes:** Because demand outpaces approval, unapproved "clascoterone" or "Breezula" solutions may be offered by compounding sources or online sellers of variable quality. What to look for is a legitimate prescription pathway and a reputable compounding pharmacy with verifiable quality controls, rather than unverified online products of unknown concentration or purity.
* **Formulation matters:** The hair-loss evidence is specific to the 5% scalp solution used in trials; repurposing the 1% acne cream for the scalp is not equivalent in concentration, vehicle, or delivery, and is not supported by the trial data.
* **Reputable channels:** Where clascoterone becomes available for hair loss, sourcing through the approved manufacturer's product or a licensed pharmacy — rather than gray-market suppliers — is the reliable route; specialist hair-restoration clinics are likely to be early legitimate access points.
## Practical Considerations
* **Time to effect:** As with essentially all pattern hair loss treatments, visible change is slow. The pivotal trials measured primary outcomes at around 6 months, and meaningful cosmetic improvement typically takes several months of consistent twice-daily use before it is apparent.
* **Common pitfalls:** Stopping early because "nothing is happening" before the multi-month timeline; overapplying in hopes of faster results (which raises irritation and exposure without proven benefit); confusing the 1% acne cream with the 5% scalp solution; and expecting regrowth on long-bald areas where follicles are no longer viable.
* **Regulatory status:** For hair loss the drug is investigational/not yet approved; any pre-approval use is off-label. The 1% cream is FDA-approved only for acne. Approval decisions for the hair-loss solution were still pending at the creation date.
* **Cost and accessibility:** Because the hair-loss solution is not yet marketed, access is currently limited and cost is not established; early availability may be constrained and, as a newer branded product, it is likely to be more expensive than generic minoxidil once launched.
## Interaction with Foundational Habits
* **Sleep:** Interaction is **none/indirect**. Clascoterone is a locally acting topical with negligible systemic exposure and no known central or stimulant activity, so it is not expected to disrupt or improve sleep. There are no timing considerations relative to bedtime beyond letting the solution dry.
* **Nutrition:** Interaction is **indirect**. The drug itself has no established dietary interaction, but hair growth overall depends on adequate protein, iron, and micronutrient status; the pivotal trials specifically excluded people with significant nutrient deficiencies or malabsorption, implying that correcting deficiency supports the outcome the drug is trying to achieve. No specific foods need to be included or avoided for the drug's action.
* **Exercise:** Interaction is **none/indirect**. There is no evidence that exercise blunts or enhances clascoterone's follicular effect, and no timing relationship to workouts. Heavy sweating immediately after application could theoretically wash product off, so allowing the solution to dry and spacing application away from intense sweating sessions is a sensible practical measure.
* **Stress management:** Interaction is **indirect**. Chronic stress can worsen some forms of hair shedding (e.g., telogen effluvium) that are separate from androgenetic miniaturization, so stress control supports overall scalp coverage without changing clascoterone's mechanism. Separately, because clascoterone carries a theoretical effect on the body's cortisol-control (HPA) axis, there is a conceptual link to the stress-hormone system, but no practical stress-management adjustment is indicated at topical doses.
## Monitoring Protocol & Defining Success
Baseline assessment for clascoterone is primarily clinical rather than laboratory-based, because the drug's systemic exposure is low. Before starting, the practical baseline is documentation of the starting state of the hair — standardized scalp photographs and, where available, a hair count in the target area — plus confirmation that the scalp skin is healthy and, for women of reproductive potential, pregnancy status. Routine blood work is not required for healthy users; the optional labs below apply mainly to higher-risk individuals (adrenal or potassium disorders) given the drug's theoretical signals.
Ongoing monitoring is chiefly about tracking response and tolerability rather than safety labs. A reasonable cadence mirrors the trials: reassess at roughly 3 months (early tolerability and adherence), at 6 months (the point at which trial efficacy was measured), and then every 6-12 months to judge maintenance. Optional labs, when indicated by baseline risk, would be checked at baseline and repeated only if symptoms arise.
| Biomarker | Optimal Functional Range | Why Measure It? | Context/Notes |
|-----------|--------------------------|-----------------|----------------|
| Target/Total Area Hair Count (TAHC) | Increase over baseline in the treated zone | Direct, objective measure of regrowth — the trial's primary endpoint | Requires standardized photography of a fixed scalp zone; best assessed at 6 months and beyond; TAHC = the standardized count of hairs in a defined scalp area |
| Serum potassium | ~4.0-4.5 mmol/L (mid-normal) | Screens for the isolated hyperkalemia (high potassium) signal seen in controlled studies | Optional; relevant mainly for those on potassium-raising drugs or with kidney/adrenal disease. Conventional lab range (~3.5-5.0 mmol/L) is wider than the mid-range functional target |
| Morning cortisol / ACTH-stimulation response | Normal adrenal response (no suppression) | Screens for the theoretical HPA-axis (stress-hormone) effect flagged in acne studies | ACTH = adrenocorticotropic hormone, the pituitary signal that tells the adrenal glands to make cortisol. Optional; only for those with adrenal concerns. Best drawn in the morning; a stimulation test is the definitive check if suppression is suspected |
| Ferritin (iron stores) | ~40-70 ng/mL | Low iron independently limits hair regrowth and can confound a poor response | Fasting not required; a supporting test to ensure a fair trial of the drug, not a drug-safety marker |
Qualitative markers complement the hair count and are often what the individual notices first:
* Reduced daily shedding (fewer hairs on the pillow or in the shower)
* Increased density or coverage at the part line, temples, and vertex on self-inspection
* Improved hair caliber (thicker, more pigmented hairs replacing fine vellus hairs)
* Scalp comfort and absence of persistent irritation, redness, or scaling as a tolerability check
Success is best defined conservatively: for a progressive condition, halting further loss and achieving a modest but visible increase in coverage over 6-12 months of consistent use is a realistic definition of a good response, rather than complete restoration of a full head of hair.
## Emerging Research
* **SCALP1 pivotal Phase 3 trial (male pattern hair loss):** A 6-month, multicenter, randomized, double-blind, vehicle-controlled study of clascoterone 5% solution twice daily in men, followed by a 6-month extension. Enrollment approximately 703; primary endpoints were change in non-vellus Total Area Hair Count and subjects' own assessment of hair coverage. [NCT05910450](https://clinicaltrials.gov/study/NCT05910450). Top-line results reported significant hair-count improvement versus vehicle; full peer-reviewed publication was still awaited at the creation date.
* **SCALP2 pivotal Phase 3 trial (male pattern hair loss):** The identically designed companion pivotal study, enrollment approximately 762, with the same twice-daily 5% solution regimen and the same hair-count and self-assessment endpoints. [NCT05914805](https://clinicaltrials.gov/study/NCT05914805). Together SCALP1 and SCALP2 constitute the largest Phase 3 program conducted for a topical male pattern hair loss agent.
* **Phase 2 dose-finding and active-comparator groundwork:** An earlier Phase 2 study compared cortexolone 17α-propionate (CB-03-01) 5% solution against minoxidil 5% and vehicle over 26 weeks in men (enrollment approximately 95), providing the target-area hair-count signal and safety basis that justified the Phase 3 program. [NCT02279823](https://clinicaltrials.gov/study/NCT02279823).
* **Open question — durability and maintenance:** A key future-research direction is whether the 6-month gains are maintained or extended over the longer term; the SCALP extension phases and any planned long-term follow-up will determine how the effect holds with continued twice-daily use, which could strengthen the case for the drug.
* **Open question — women and combination therapy:** No completed controlled trials address female pattern hair loss or clascoterone combined with minoxidil; studies in either direction could meaningfully expand — or, if negative, temper — the drug's role, and the antiandrogen mechanism reviewed in [Antiandrogen therapy for the treatment of female pattern hair loss: A clinical review of current and emerging therapies](https://pubmed.ncbi.nlm.nih.gov/40345536/) - Ong et al., 2025 frames why female-specific data are needed.
* **Open question — independent confirmation and full publication:** Because current enthusiasm rests substantially on company top-line disclosures, a study-weakening as well as study-strengthening consideration is that independent, fully published trial data and any regulatory review could either confirm the reported magnitude or reveal a more modest real-world effect.
## Conclusion
Clascoterone is a topical drug that blocks male-type hormones directly at the hair follicle, aiming to slow the follicle shrinkage behind pattern hair loss while sparing the rest of the body from hormonal effects. First approved in a weaker form for acne, a stronger scalp solution has now been tested in two large studies in men, which reported clear, measurable regrowth compared with an inactive solution over six months. Its main appeal is delivering an anti-hormone effect only where it is applied, avoiding the sexual and hormonal concerns that lead many people to reject the oral alternatives.
The evidence is promising but still early. Much of what is known about regrowth comes from recently announced results released by the drug's maker rather than fully published, independently reviewed reports — a conflict of interest that means the headline figures should be read as company claims awaiting outside confirmation — and the drug is not yet approved for hair loss. Its safety signals so far are mild and mostly limited to skin irritation, with only minor, reversible laboratory concerns and little sign of body-wide effects. Longer-term durability, effects in women, and confirmation of the reported benefit remain open. For someone weighing a locally acting option that sidesteps whole-body hormone changes, clascoterone represents a genuinely new direction whose real place among hair-loss treatments will become clearer as complete data emerge.
**[Top](#top) - [Benefits](#expected-benefits) - [Risks](#potential-risks--side-effects) - [Protocol](#therapeutic-protocol)**