Hair loss treatments have been stuck in the same place for decades. Minoxidil was approved in 1988. Finasteride came in 1997. Since then, nothing fundamentally new has reached the market for androgenetic alopecia (male pattern baldness). Your options have been the same for nearly 30 years: stimulate growth with minoxidil, block DHT with oral finasteride or dutasteride, or pursue hair transplants.

That changed on December 3, 2025, when Cosmo Pharmaceuticals announced breakthrough results from two massive Phase 3 trials testing clascoterone 5% topical solution. The SCALP trials represent the largest clinical program ever conducted for a topical hair loss treatment, enrolling 1,465 men across the United States and Europe. The results showed something the hair loss world has been waiting for: a topical treatment that blocks DHT locally at the hair follicle without systemic hormone suppression.

One trial showed a 539% relative improvement in hair count compared to placebo. The other showed 168% improvement. Both hit statistical significance. The safety profile looked similar to placebo, with no signal of systemic hormonal side effects reported in the topline data. If these results hold up through regulatory review and FDA approval (potentially in 2026 at the earliest), clascoterone could represent the first truly new mechanism approved for pattern hair loss in over three decades.

This article breaks down what the SCALP trials actually showed, what those percentage improvements really mean, how this compares to finasteride and minoxidil, who might benefit most, and what happens next as the medication moves toward potential regulatory approval.

Understanding DHT and Why Blocking It Matters

Androgenetic alopecia affects roughly 50% of men by age 50 and significant numbers of women, though with different patterns. The process is driven by dihydrotestosterone (DHT), an androgen hormone derived from testosterone through an enzyme called 5-alpha reductase.

In genetically susceptible hair follicles, DHT binds to androgen receptors and triggers progressive miniaturization. Over time, affected follicles produce thinner, shorter, lighter hairs until they eventually stop producing visible hair. The follicles shrink, the growth phase shortens, and the hair becomes fine and barely visible.

This process is progressive and ongoing. Hair loss treatments need to be continuous because you are managing an active process, not fixing a problem that stays fixed once solved. The miniaturization resumes when treatment stops.

The most effective treatments either reduce DHT production systemically (finasteride, dutasteride taken orally) or block DHT from binding to follicle receptors. Until now, blocking androgen receptors required oral medications with systemic effects throughout your body. Clascoterone represents the first topical option that blocks these receptors locally at the scalp.

What Is Clascoterone and How Does It Work?

Clascoterone is a topical antiandrogen that blocks androgen receptors directly where you apply it. Unlike oral DHT blockers that reduce DHT throughout your entire body, clascoterone binds to androgen receptors in hair follicles and prevents DHT from attaching and triggering miniaturization.

The medication is applied topically to the scalp where it gets absorbed locally. It has very low systemic absorption based on previous pharmacokinetic studies, meaning minimal amounts enter your bloodstream to affect androgen receptors elsewhere in your body. This local action is the key advantage. By blocking DHT effects specifically in the scalp while leaving systemic hormone levels largely unchanged, it aims to achieve hair regrowth without the potential sexual or hormonal side effects associated with oral DHT blockers.

Clascoterone was initially developed and FDA-approved as Winlevi 1% cream for treating acne in 2020. The same mechanism that makes it work for acne (blocking androgen receptors in sebaceous glands) made it a candidate for hair loss. However, the hair loss formulation uses a higher concentration (5% solution versus 1% cream for acne) and different vehicle designed for scalp application.

The formulation tested in the SCALP trials is a 5% topical solution applied twice daily to affected areas of the scalp. Like all hair loss treatments, it needs continuous use to maintain benefits. Stopping allows DHT to resume its effects on follicles.

It is crucial to understand that clascoterone for hair loss is not yet FDA approved. The SCALP trial topline results were announced December 3, 2025. Cosmo Pharmaceuticals plans to submit for FDA and European regulatory approval after completing 12-month safety follow-up data in spring 2026. If approved, the medication could potentially become available in late 2026 or 2027, though regulatory timelines are inherently unpredictable. The medication is investigational at this point, not commercially available for hair loss treatment.

The SCALP Trials: What Was Actually Tested

The SCALP program consisted of two identically designed Phase 3 trials: SCALP-1 (NCT05910450) and SCALP-2 (NCT05914805). Understanding the trial design helps interpret what the results actually mean.

Both were randomized, double-blind, vehicle-controlled studies, the gold standard for clinical research. A total of 1,465 men were enrolled across 50 sites in the United States, Germany, and Poland. This makes it the largest Phase 3 program ever conducted for any topical hair loss treatment. Participants were adult men (age 18 and older) with male pattern hair loss. The trials randomly assigned men to receive either clascoterone 5% solution or placebo (vehicle solution without active drug) applied twice daily to the scalp for 6 months.

The co-primary endpoints were change in Target-Area Hair Count (TAHC) within specific scalp regions measured using specialized photography and computer-assisted counting, and patient-reported outcomes (PROs) assessing perceived improvement in hair growth and satisfaction. After the initial 6-month double-blind phase, both trials included a planned 6-month single-blind extension to gather longer-term safety and durability data, which is still ongoing.

The design allows for objective measurement of hair regrowth while also capturing whether patients actually perceived and felt satisfied with the changes. Both objective measurement and subjective patient experience matter for a treatment addressing something as personal and psychologically impactful as hair loss.

SCALP Trial Results

The results announced December 3, 2025 are topline results, meaning the key headline findings without full detailed data publication. The complete dataset will be published in peer-reviewed journals later, but the topline results provide important information.

Based on topline data only: Both trials met their primary endpoint with statistical significance. SCALP-1 showed a 168% (1.68-fold) relative improvement in Target-Area Hair Count compared to placebo. SCALP-2 showed a 539% (5.39-fold) relative improvement compared to placebo. The pooled analysis across both trials showed approximately 252% relative improvement versus placebo.

You might be wondering how one trial shows 539% improvement while the other shows 168% if the drug works the same way. The difference comes down to baseline hair counts, not drug performance. When participants start with lower baseline hair counts, even the same absolute increase in hair number translates to a larger percentage improvement. If one group gains 15 hairs from a baseline of 10 hairs, that is a 150% improvement. If another group gains 15 hairs from a baseline of 30 hairs, that is a 50% improvement. Same absolute gain, different relative percentages.

Cosmo Pharmaceuticals CEO Giovanni Di Napoli clarified that the difference between trials is "entirely by baseline hair counts, not by a difference in drug performance." The absolute hair count gains appear to have been similar across both trials, but the relative percentages differed due to different starting points.

These relative improvement numbers sound dramatic (539% improvement sounds huge), but it is important to understand what they actually represent. A 539% improvement means the clascoterone group gained 5.39 times more hair than the placebo group in the target area. This is meaningful and statistically significant, but it does not mean participants grew 5 times more total hair on their heads or went from bald to fully covered. The actual absolute hair count numbers have not been published yet in the topline results.

The patient-reported outcomes supported the objective findings. One trial reached statistical significance on its PRO endpoint while the other showed a positive trend. The combined analysis across both trials was statistically significant, indicating that patients both experienced and perceived meaningful improvement in their hair growth.

Safety Profile: What Side Effects Occurred?

The safety data from the SCALP trials is as important as the efficacy data, particularly given that a major advantage of topical versus oral DHT blockade is supposed to be fewer systemic side effects.

Based on topline data only: Treatment-emergent adverse events (TEAEs) were similar between the clascoterone and placebo groups. In the clascoterone groups, 5.1% of participants experienced TEAEs. In the placebo groups, 6.1% experienced TEAEs. This essentially identical rate suggests the medication is well-tolerated with a safety profile comparable to vehicle alone.

Most reported side effects were mild to moderate in severity and were not related to the study drug according to the topline announcement. The types of side effects reported were similar between clascoterone and placebo, further supporting that the medication itself is not causing significant adverse effects beyond what occurs with the vehicle solution.

According to the topline announcement, no signal of systemic hormonal side effects has been reported so far, though detailed hormone measurement data from the Phase 3 hair loss program have not yet been published. Previous studies of clascoterone in other formulations showed minimal systemic absorption and no significant effects on circulating hormones, which supports the mechanism of local action at the scalp rather than systemic hormone suppression.

This safety profile would represent a key distinction from oral finasteride, which can cause sexual side effects (decreased libido, erectile dysfunction) in roughly 2 to 5% of users based on clinical trial data. The SCALP topline data did not indicate increased sexual adverse events in the clascoterone group compared to placebo, though full safety data publication will provide more detailed information.

The topline safety data extends to 6 months. The ongoing 12-month safety extension will provide longer-term data, which is important for a medication intended for chronic use. Cosmo plans to complete this safety follow-up in spring 2026 before regulatory submissions.

What We Don't Know Yet: Limitations of Topline Results

While the SCALP trial results are encouraging, it is important to understand the limitations of topline announcements before full data publication.

We do not yet have detailed breakdowns of response by baseline severity of hair loss, age groups, specific scalp regions treated, or other subgroup analyses. We do not know the absolute hair count numbers, only the relative improvement percentages compared to placebo. Full statistical analyses, detailed safety breakdowns, comprehensive hormone data, and complete results will come when the data is published in peer-reviewed journals, likely in 2026.

The trials only included men, so data for women with pattern hair loss from this specific program remains limited. Some earlier smaller studies suggested clascoterone might work in women, but robust Phase 3 data in female populations does not yet exist from the SCALP trials.

The efficacy follow-up period is currently 6 months with ongoing extension to 12 months for safety. Longer-term data beyond one year does not exist yet. For a treatment intended for years or decades of use, understanding very long-term safety and sustained efficacy matters.

We do not know pricing, insurance coverage, or practical access details since the medication is not yet commercially available for hair loss. We do not know how clascoterone performs in combination with other treatments like finasteride or minoxidil, though the complementary mechanisms suggest potential benefits from combinations.

These limitations do not invalidate the positive results, but they mean our understanding of clascoterone for hair loss will continue evolving as more data becomes available through publication and post-approval real-world use if the medication receives regulatory clearance.

How This Might Compare to Established Treatments

Understanding how clascoterone might stack up against finasteride and minoxidil helps contextualize what these results could mean for future treatment options, though direct comparisons are limited by different trial designs and endpoints.

Finasteride has decades of data showing it increases hair count significantly in men with pattern hair loss. Studies consistently show that finasteride 1 mg daily produces meaningful hair regrowth sustained over years of use. The medication reduces scalp and serum DHT by approximately 70%, addressing the hormonal driver of miniaturization systemically.

The efficacy comparison between clascoterone and finasteride is challenging because the SCALP trials reported relative improvements (fold-changes versus placebo) rather than the same absolute measurements used in finasteride trials, and direct head-to-head trials do not exist. What we can say is that both medications work through DHT-related mechanisms but via different routes (topical receptor blockade versus systemic DHT reduction).

If approved, the advantage of clascoterone over finasteride would likely lie primarily in the safety profile. The SCALP topline data showed adverse event rates matching placebo with no reported signal of systemic hormonal effects. For men concerned about potential sexual side effects of oral finasteride, a topical option with local action could offer appeal even if efficacy proves different once we have full comparative data.

Minoxidil works through a completely different mechanism than either finasteride or clascoterone. It stimulates hair follicles through vasodilation and other effects not related to hormones. This makes minoxidil complementary to DHT-blocking approaches. Many dermatologists recommend minoxidil as a foundation with either oral or topical DHT blockade added depending on patient preference.

The mechanistic differences suggest that combining clascoterone (if approved) with minoxidil might offer benefits beyond either alone. Clascoterone would prevent hormonal miniaturization while minoxidil actively stimulates growth. While specific combination trial data does not exist, the rationale supports potentially using both simultaneously.

Current Status and What Comes Next

Clascoterone 5% solution for hair loss is investigational and not approved or commercially available. Here is what needs to happen before it could reach patients.

Cosmo Pharmaceuticals is completing 12-month safety and durability follow-up for both SCALP trials, expected to finish in spring 2026. After this data is collected, the company plans parallel regulatory submissions to the FDA in the United States and the European Medicines Agency in Europe.

The regulatory review process typically takes 6 to 12 months or longer depending on the agency's questions and the completeness of submitted data. If approved, commercial launch would follow regulatory clearance. Realistically, clascoterone for hair loss is unlikely to be available to patients before late 2026 at the earliest, and could potentially extend into 2027 or beyond depending on how regulatory reviews proceed.

Pricing has not been announced. The medication would require a prescription if approved. Insurance coverage for hair loss treatments varies widely, with many plans considering them cosmetic and excluding coverage. How insurers might approach clascoterone remains unknown until and unless it reaches the market.

Full publication of the SCALP trial results in peer-reviewed medical journals will provide the detailed data that topline announcements do not include. This will allow independent experts to fully evaluate the methodology, results, and clinical significance of the findings beyond the company's press release.

What This Means for People With Hair Loss Right Now

The SCALP results are exciting and represent genuine progress in hair loss treatment options. However, the medication is not available yet, so immediate treatment decisions must be based on currently approved and accessible options.

For men currently using finasteride or minoxidil with good results, there is no reason to stop based on these announcements. Switching to an investigational treatment not yet available would mean giving up effective therapy for an uncertain future option.

For men who have avoided finasteride due to side effect concerns or who have not achieved desired results with minoxidil alone, clascoterone represents a potential future option worth monitoring. If the medication receives approval, it could offer a middle ground between topical minoxidil (which does not address DHT) and oral finasteride (which has systemic effects some men want to avoid).

For men not currently treating their hair loss, starting established treatments now rather than waiting for clascoterone makes sense if hair loss is progressing. Every month of untreated miniaturization represents follicles becoming harder to recover. Finasteride and minoxidil are available, effective, and well-studied options you can start now.

At Mochi Health, we offer evidence-based hair loss treatments including finasteride and minoxidil. Our providers can help you develop a personalized approach based on your pattern of hair loss, goals, concerns about side effects, and individual circumstances. While clascoterone is not yet available, we stay informed about emerging treatments and will incorporate new options as they become approved and accessible. You can explore our current hair loss treatment options at https://joinmochi.com/medications#skin-hair.

Check Your Eligibility

If you want to learn about current hair loss treatment options and receive personalized guidance from providers who stay informed about emerging treatments like clascoterone, you can start by completing Mochi's eligibility questionnaire. It takes just a few minutes and helps our clinical team understand your goals and health needs. Check your eligibility here: https://app.joinmochi.com/eligibility.

References

Cosmo Pharmaceuticals. (2025, December 3). Cosmo announces breakthrough Phase III topline results from SCALP 1 and SCALP 2 for clascoterone 5% solution in male hair loss [Press release]. https://www.cosmopharma.com/news/cosmo-announces-breakthrough-phase-iii-topline-results-from-scalp-1-and-scalp-2-for-clascoterone-5-solution-in-male-hair-loss-showing-up-to-539-relative-improvement-in-target-area-hair-count-vs-place 

Kaufman, K. D., Olsen, E. A., Whiting, D., Savin, R., DeVillez, R., Bergfeld, W., Price, V. H., Van Neste, D., Roberts, J. L., Hordinsky, M., Shapiro, J., Binkowitz, B., & Gormley, G. J. (1998). Finasteride in the treatment of men with androgenetic alopecia. Journal of the American Academy of Dermatology, 39(4), 578-589. https://doi.org/10.1016/s0190-9622(98)70007-6

Olsen, E. A., Dunlap, F. E., Funicella, T., Koperski, J. A., Swinehart, J. M., Tschen, E. H., & Trancik, R. J. (2002). A randomized clinical trial of 5% topical minoxidil versus 2% topical minoxidil and placebo in the treatment of androgenetic alopecia in men. Journal of the American Academy of Dermatology, 47(3), 377-385. https://doi.org/10.1067/mjd.2002.124088

Suchonwanit, P., Thammarucha, S., & Leerunyakul, K. (2019). Minoxidil and its use in hair disorders: A review. Drug Design, Development and Therapy, 13, 2777-2786. https://doi.org/10.2147/DDDT.S214907

Varothai, S., & Bergfeld, W. F. (2014). Androgenetic alopecia: An evidence-based treatment update. American Journal of Clinical Dermatology, 15(3), 217-230. https://doi.org/10.1007/s40257-014-0077-5

This article is for educational purposes only and should not be considered medical advice. Consult with healthcare providers about whether current hair loss treatments are appropriate for your individual needs and circumstances.