Back in December 2025, Cosmo Pharmaceuticals dropped some news that caught a lot of people’s attention. They announced results from two Phase 3 trials of clascoterone 5% topical solution for male pattern baldness (androgenetic alopecia).
The numbers sounded huge—up to 539% relative improvement in hair count compared to placebo. For a condition that hasn’t seen a genuinely new mechanism since finasteride came out in the late 90s, that’s a pretty big deal.
But what do those numbers actually mean in real life? Is clascoterone actually going to change how people treat hair loss, or is it just another option to add to the list? Let’s walk through what the data really shows.
Most people who’ve looked into hair loss treatments have heard the usual explanations. Finasteride and dutasteride block an enzyme called 5-alpha reductase, which lowers DHT levels throughout your body. Minoxidil does something to blood flow around follicles, though honestly nobody’s completely sure how it works.
Clascoterone is different. It’s a topical androgen receptor inhibitor. That means it stops DHT from binding to receptors right there in your scalp, where the problem starts, without getting absorbed into your bloodstream in significant amounts.
A 2019 study in the Journal of Drugs in Dermatology tested this in the lab. They found that clascoterone blocked androgen receptor activity about as well as finasteride did in a cell-based test. And here’s the clever part: the drug is designed as a “soft drug.”
It works strongly where you put it—on your scalp—but once it gets into your bloodstream, it breaks down quickly into a much less active form. So the idea is local effect, minimal body-wide exposure.
Cosmo ran two studies called SCALP-1 and SCALP-2. Together they enrolled 1,465 men across the US and Europe. That makes it the largest Phase 3 program ever done for a topical hair loss treatment. The main thing they measured was change in target-area hair count (TAHC)—basically, how many hairs grew back in a specific small area of the scalp.
Here’s the topline data:
Study | Relative Improvement vs. Placebo | Absolute Numbers |
SCALP-1 | 539% (5.39x) | Not publicly released yet |
SCALP-2 | 168% (1.68x) | Not publicly released yet |
Both studies hit statistical significance. The big difference between the two studies? Cosmo’s CEO explained it this way: if two groups get a similar absolute increase in hair count but start from different baselines, the group with the lower baseline shows a much bigger relative percentage. So the drug seems to have worked consistently—the starting hair counts were just different between the two trial populations.
They also looked at patient-reported outcomes across both studies, and those were statistically significant too, matching what the hair count numbers showed.
This is actually what makes clascoterone interesting. Topical anti-androgens have failed before because they got absorbed into the bloodstream and caused the same side effects as the oral pills.
In the SCALP trials, side effects were about the same as placebo. No serious adverse events were reported. Some people had mild itching or skin irritation—similar to what you’d get with topical minoxidil. But here’s an important caveat: there’s no long-term safety data yet. Cosmo hasn’t completed the 12-month follow-up. They’ve said they won’t seek approval until they have that data, which should be ready in spring 2026.
Dr. Maria Hordinsky, a dermatology professor at the University of Minnesota who was involved in the trials, put it this way: for years, patients have had to choose between options that either don’t work very well or have side effects from systemic hormone exposure. Clascoterone, she said, could change that by giving real regrowth with almost no systemic exposure.
Treatment | How It Works | How You Take It | Main Downside |
Minoxidil (topical) | Improves blood flow? Lengthens growth phase? (not fully understood) | Topical | Works for some people, not others; initial shedding |
Finasteride (oral) | Blocks type II 5-alpha reductase | Oral pill | Sexual side effects in about 3-5% of men |
Dutasteride (oral) | Blocks both type I and II 5-alpha reductase | Oral pill | More potent, similar side effect profile |
Clascoteron (not yet approved) | Blocks androgen receptors locally | Topical | Not approved; absolute hair count numbers not yet public |
Nobody has run a head-to-head trial directly comparing clascoterone to finasteride or minoxidil. So we don’t actually know which one works better.
The absolute hair counts. That 539% number sounds amazing, but without knowing the actual number of hairs gained, it’s hard to say what it means for someone standing in front of a mirror. A small absolute gain can look like a huge percentage if you start from a very low baseline.
How it works in women. The Phase 3 trials only included men. For women with female pattern hair loss, we don’t really have good data yet.
Long-term safety. The 12-month follow-up isn’t finished. Cosmo is targeting spring 2026 to complete that and then file for approval in the US and Europe.
When it might actually be available. Best case? Not before 2027. Probably later.
Realistically, clascoterone probably won’t replace finasteride or minoxidil for people with advanced hair loss. But it could be useful in a few situations:
One analysis I read put it well: clascoterone isn’t a miracle cure by itself. It’s more of a supportive option that might work well as part of a combination approach.
At Tianming Pharmaceutical, we manufacture clascoterone API (CAS 19608-29-8) for R&D use. It’s a steroid-based molecule, and making it at high purity requires careful control of stereochemistry and impurities.
Our product is intended for preclinical and clinical development programs. As clascoterone moves closer to potential approval for hair loss, having a reliable, quality-controlled supply of the API is going to matter more.
Is clascoterone FDA-approved for hair loss yet?
No. The 1% cream (Winlevi) is approved for acne. The 5% topical solution for hair loss is still investigational.
Does it regrow hair or just stop further loss?
Based on the Phase 3 data, it seems to do both. Hair count went up compared to placebo, so it’s not just preventing loss—it’s actually regrowing hair.
Can women use it?
The Phase 3 trials only studied men. We don’t have good data for women yet.
What are the side effects?
Mostly mild skin stuff—itching, redness, dryness. No systemic hormonal side effects were reported in the topline data.
How does it compare to finasteride?
Nobody’s run a head-to-head trial. Lab studies suggest similar androgen-blocking activity, but clinical comparison isn’t available.
At Tianming Pharmaceutical, we supply high-purity clascoterone API (CAS 19608-29-8) for pharmaceutical development. Our product is manufactured under strict quality controls. For technical specifications or to request a sample, contact our team. sunqian0123@gmail.com
Clascoterone for hair loss: Phase 3 trials show significant regrowth with minimal systemic absorption. How it works, side effects, and comparison to finasteride.
Does GLP-1 cause hair loss? Yes, studies on 1.1M+ patients show an association—driven by rapid weight loss, not direct drug toxicity. Telogen effluvium is temporary. New oral drug Foundayo (orforglipron) included.
Comparing orforglipron vs tirzepatide: tirzepatide shows greater weight loss (-20.9% vs -12.4%), but orforglipron offers oral dosing, easier manufacturing, and potential for better long-term adherence.
Leading provider of high-quality APIs and intermediates. Contact us for innovative solutions and expert support.