How long does it take for clascoterone to show results on hair growth?

Clascoterone, also known as CB-03-01 or by its investigational brand name Breezula, is a topical antiandrogen being developed for hair loss conditions like androgenetic alopecia (AGA). The compound blocks androgen receptors in the skin, which locally inhibits the effects of dihydrotestosterone (DHT), a hormone strongly implicated in hair follicle miniaturization and thinning. Unlike oral medications such as finasteride that lower DHT throughout the body, clascoterone is designed to act where it is applied—most often the scalp—and the manufacturer's pharmacokinetic data show very little of it reaching the bloodstream. It is worth saying at the outset that clascoterone is not approved for hair loss anywhere: the approved product is a 1% acne cream, and the scalp version remains investigational.

When do results start to appear?

Clinical trials investigating clascoterone for hair regrowth have used varying concentrations (commonly 5% and 7.5%) across different demographics, including adult men and women. The results so far come from company announcements, not peer-reviewed publications. The company reports that:

• Around 6 months is when the trials took their main hair-count measurement, and increases in terminal hair count (i.e., thick, pigmented hairs rather than miniaturized, vellus hairs) were reported at that point.
• By 12 months, more sustained improvements in hair density and scalp coverage have been reported.

For example, in the sponsor's reported phase II results in women, females under the age of 30 showed a statistically significant increase in terminal hair count when treated with 5% topical clascoterone compared to a placebo. In other subgroups—older women, and those using different concentrations—the improvements trended positively but did not reach statistical significance. Findings confined to one age subgroup are weaker evidence than a result across the whole trial, and should be read that way. The trials measured hair counts at set time points, around 6 and 12 months; there is no published evidence on how early a person might notice a change. In the sponsor's April 2026 release on 12-month Phase III data for the 5% solution, men who stayed on treatment were reported to keep gaining hair through month 12, while men switched to placebo from month 7 lost some of their gain. These data come from a company press release and have not been peer-reviewed. Trial protocols required consistent daily application, so the reported timelines assume that.

Differences by type of alopecia

While clascoterone is being studied for androgenetic alopecia (AGA), not all hair loss disorders are influenced by androgens—and so not all types would be expected to respond to antiandrogen treatments:

• Androgenetic Alopecia (AGA): This is the most common form of hair loss in both men and women and is influenced by the effects of DHT on scalp hair follicles. Clascoterone's DHT-blocking mechanism is intended to counter follicle miniaturization and prolong the anagen (growth) phase. Essentially all the clinical evidence on clascoterone for hair loss comes from AGA patients.

• Alopecia Areata or Universalis: These are autoimmune conditions in which the immune system attacks the hair follicles. The role of androgens in these diseases is minimal or nonexistent. Clascoterone is not a treatment for alopecia areata, and other therapies, such as corticosteroids or Janus kinase (JAK) inhibitors, are what dermatologists use instead.

• Scarring Alopecias or Traction Alopecia: These conditions involve permanent damage to the follicle, often due to inflammation, injury, or prolonged mechanical stress. Once follicles are destroyed or scarred, hair regrowth becomes extremely difficult or impossible without surgical intervention. As clascoterone targets hormonal pathways and not regenerative or inflammatory ones, there is no reason to expect benefit in these cases.

This distinction matters for patients and practitioners alike. Identifying the cause of hair loss is the first step in choosing a treatment—and the evidence for clascoterone is limited to hormonal, non-scarring hair loss. A dermatologist's diagnosis is what tells you which category you are in.

Current clascoterone-based treatments in development

Clascoterone was approved by the FDA in 2020 for acne (under the brand name Winlevi), but it has not been approved for treating hair loss. Several trials have evaluated it for androgenetic alopecia:

• Phase III Trials in Men: Two large studies registered as NCT05910450 (703 participants) and NCT05914805, known as SCALP2 (762 participants), began in 2023 to evaluate the efficacy and safety of clascoterone solution in adult men — around 1,500 men between them. Both are now listed as completed on ClinicalTrials.gov, and the sponsor has reported positive top-line results; regulators have not yet reviewed the full data.

• Phase II Trials in Women: The sponsor has reported a multicenter, double-blind study in women comparing 5% and 7.5% clascoterone solutions with minoxidil and placebo over six months, in which clascoterone was described as well tolerated. Women under 30 showed statistically significant increases in terminal hair count, while results across the broader population were more variable. These results were announced by the company rather than published in a peer-reviewed journal, which limits how much weight they can carry.

These studies determine not just whether clascoterone works, but for whom and at what concentration. Any treatment protocol would follow a regulatory approval, which has not happened yet.

Comparison with other topical treatments

To place clascoterone in the therapeutic landscape, it is useful to compare it with other topical options used for androgenetic alopecia:

• Minoxidil: Approved for both men and women, minoxidil is a vasodilator that prolongs the anagen phase of hair follicles. Results are typically reported within 3 to 6 months. It is a first-line therapy but does not address the hormonal driver of hair thinning.

• Finasteride (topical and oral): Finasteride inhibits the enzyme 5-alpha-reductase, which converts testosterone to DHT. The oral form has the largest evidence base of any AGA drug, and carries a risk of systemic side effects that should be discussed with a prescriber. The UK regulator (MHRA, May 2026) states that finasteride is associated with depression, suicidal thoughts and sexual dysfunction "which may persist after treatment is stopped", and advises stopping finasteride 1 mg immediately and contacting a doctor if depression or suicidal thoughts develop. Topical finasteride has a smaller evidence base. There is no FDA-approved topical finasteride (a finasteride spray is authorised in the EU), so in the US it is compounded. In April 2025 the FDA warned about side effects reported with compounded topical finasteride, most of which were reported to continue after stopping, and said some of the drug is expected to reach the bloodstream. Results are usually reported between 3 and 6 months. Finasteride in any form is contraindicated in pregnancy and for women who may become pregnant.

• Ketoconazole 2% Shampoo: Primarily an antifungal, ketoconazole has been reported to have mild antiandrogenic effects and is sometimes used as an adjunct. It can improve scalp condition and reduce inflammation; the evidence that it grows hair is thin.

What distinguishes clascoterone in principle is that it blocks DHT at the receptor in the skin rather than lowering DHT in the bloodstream. If the trials bear that out, it may appeal to patients concerned about systemic effects — but it is not yet an available option for hair loss, so this is a comparison of prospects, not of products on the shelf.

Hair growth stages and expected outcomes

Hair growth follows a well-established cycle composed of three main stages:

• Anagen (Growth Phase): This is the active growth period of hair follicles, lasting several years. The goal of most treatments, including clascoterone, is to prolong this phase, allowing for thicker and longer hair. Trials of clascoterone over 6 to 12 months have reported increases in terminal hair count, which is what a shift toward anagen looks like on a hair count.

• Catagen (Transition Phase): A brief period when hair growth slows and the follicle begins to shrink. This stage typically lasts only a few weeks and is not a direct target of therapeutic intervention.

• Telogen (Resting/Shedding Phase): During this phase, hair stops growing and eventually falls out to make room for new growth. A high percentage of follicles in telogen is often associated with thinning. Antiandrogen treatments aim to shorten this phase by encouraging earlier re-entry into anagen.

For patients with androgenetic alopecia, a response to treatment is typically marked by an increase in anagen hairs, a decrease in telogen hairs, and an overall improvement in hair thickness and density. These changes take several months to show up, which is why trials run for six to twelve months.

User Experiences

Topical clascoterone (in development as Breezula for AGA) is discussed in the community as a possible DHT-blocking option for people looking for alternatives to finasteride or to RU58841 — the latter being an unapproved research chemical with no human safety data. But how long does it take to see results? Community posts describe lived experience and real-world timelines, which are anecdotes rather than evidence. Many users report that clascoterone does not produce rapid results—patience is essential.

One notable post is from a participant in a phase III clinical trial, who agreed to have a section of their scalp shaved and tattooed so results could be monitored over six months. They expected visible hair growth only toward the end of the trial, which matches the point that even in a structured research setting antiandrogen therapies are assessed over months, not weeks. In broader community discussions, people using clascoterone as part of multi-treatment regimens (often alongside minoxidil, topical finasteride, or tretinoin) described improvements in density and reduced shedding around four to five months in. Those users attribute the result to the combination rather than to clascoterone alone, which is exactly why anecdotes from stacked regimens cannot show what any single ingredient did.

A point raised repeatedly is that results are not immediate and are subtle early on. Users trying it as a monotherapy often report frustration in the first 2–3 months, and describe stabilization around month 4. Community members say the absence of reported systemic side effects is what attracts them to it for long-term use, though the trials so far are too short to speak to long-term safety. Some posts express hope for clascoterone as a localized DHT blocker for people who had side effects on systemic treatments. Community sentiment is clear on one thing: expectations should be managed, and at least six months of use is generally considered necessary before judging it.

In summary, Tressless users describe clascoterone as taking four to six months to show visible improvement in density, with earlier changes being more about slowing loss than regrowing hair. Like most hair loss treatments, consistency over the long term is what users say matters.

Clear conclusion

Clascoterone is an investigational topical treatment for androgenetic alopecia with completed phase III trials in men and sponsor-reported results in women; it is not approved for hair loss and is not available as a licensed hair-loss medicine. In the trials, application was twice daily, and improvements in hair density were reported over 6 to 12 months rather than sooner. The evidence is specific to hormonally driven, non-scarring hair loss.

Regulatory review of the phase III data is what will settle which patients benefit, at what concentration, and how clascoterone fits alongside existing therapies like minoxidil.

Talk to a doctor or dermatologist before starting, stopping or combining any hair-loss treatment, and get the cause of your hair loss diagnosed first. Because clascoterone is not licensed for the scalp, anything sold for that purpose today is either the acne cream used off-label or an unregulated compounded preparation, neither of which has been assessed for hair loss — that is a conversation to have with a prescriber rather than a decision to make alone.

References

Cassiopea SpA. (2019, April 16). Cassiopea Announces Very Positive Phase II Twelve Months Results for Breezula® (Clascoterone) in Treating Androgenetic Alopecia [Company press release]. Phase II dose-ranging trial in 404 men in Germany; results announced by the sponsor and not peer-reviewed.

Clinical trial registration (NCT05910450). A Study to Evaluate the Efficacy and Safety of Clascoterone Solution in Treatment of Male Pattern Hair Loss. Phase 3, 703 men, completed. https://clinicaltrials.gov/study/NCT05910450

Clinical trial registration (NCT05914805). A Study to Evaluate the Efficacy and Safety of Clascoterone Solution in Treatment of Male Pattern Hair Loss (SCALP2). Phase 3, 762 men, completed. https://clinicaltrials.gov/study/NCT05914805

Koralewicz, M. M., & Szatkowska, O. A. (2024). Topical solutions for androgenetic alopecia: evaluating efficacy and safety. Forum Dermatologicum, 10(3), 71–78. https://journals.viamedica.pl/forum_dermatologicum/article/view/101208

Cosmo Pharmaceuticals. (15 April 2026). Phase III 12-month data for clascoterone 5% topical solution (company press release). https://www.cosmohealthconfidence.com/news/98958067-clascoterone-12-month-safety-results-ende

U.S. Food and Drug Administration. (22 April 2025). FDA alerts health care providers, compounders and consumers of potential risks associated with compounded topical finasteride products. https://www.fda.gov/drugs/human-drug-compounding/fda-alerts-health-care-providers-compounders-and-consumers-potential-risks-associated-compounded

Medicines and Healthcare products Regulatory Agency. (11 May 2026). Finasteride and dutasteride – updated safety warnings for psychiatric side effects and sexual dysfunction. Drug Safety Update. https://www.gov.uk/drug-safety-update/finasteride-and-dutasteride-updated-safety-warnings-for-psychiatric-side-effects-and-sexual-dysfunction

Tressless Community. Clascoterone study going on right now. https://reddit.com/r/tressless/comments/1cd9cxc/clascoterone_study_going_on_right_now/

Tressless Community. The ultimate regimen for density and thickness. https://reddit.com/r/tressless/comments/1fxk7up/the_ultimate_regimen_for_density_and_thick_ess/