A drug already sold as an acne cream has now been tested for a full year as a scalp solution for male pattern baldness. In a September video presentation published by Dermatology Times, dermatologist Joshua Zeichner described 12-month results from late-stage trials of clascoterone 5% solution. Side effects were similar to those of a dummy solution, and men who kept using it had a small rise in hair density from where they started1. The full data have not been published in a peer-reviewed journal.
What happened
Clascoterone is designed to block a hormone called dihydrotestosterone, or DHT, from attaching to its receptors inside hair follicles1. DHT signaling plays a central role in the gradual shrinking of follicles seen in pattern baldness, so blocking it at the scalp may interfere with that process1.
Zeichner, an associate professor of dermatology at Mount Sinai Hospital in New York City, said the 12-month data provide encouraging evidence on the treatment’s long-term safety, tolerability and effect1. Over the year, men using the solution had a safety and tolerability profile similar to men using the vehicle, the inactive base solution without the drug1. No significant hormone-related side effects were seen during the study1.
On hair growth, men who used clascoterone continuously showed a 2.39% increase in target-area hair density at 12 months compared with their starting point1. Zeichner presented this as a sign of continued improvement with ongoing use1.
The trials behind the numbers
The one-year figures build on earlier results. In January 2026, Cosmo Pharmaceuticals reported first results from two large late-stage trials, called SCALP 1 and SCALP 2, which together enrolled 1,465 men2. Those trials measured hair counts in a target area of the scalp and asked men how they rated their own hair. Both showed statistically significant improvements compared with the dummy solution, and the hair counts lined up with how the men saw their own results2. Side effects were similar to the dummy solution2.
The public trial registry gives details of SCALP 2. It enrolled 762 men and is listed as completed3. It began in August 2023, and the main data collection finished in July 20253. Its main goals were the change in hair count and the men’s own rating of their hair coverage, both at 6 months3.
The study ran in two parts. In the first, men were assigned by chance, two to one, to clascoterone or a dummy solution, applied twice a day for up to 6 months. Neither the men nor the study doctors knew who got which3. Men judged to have responded at 6 months were then assigned again, two to one, to the drug or the dummy for another 6 months. In that second part only the study doctor knew which treatment each man received3.
The men were 18 or older with mild to moderate hair loss on the crown and temples, rated III vertex to V on the Norwood-Hamilton scale, a standard chart of male balding stages4. Safety checks included heart tracings (electrocardiograms), blood and urine tests, and scalp checks for irritation4.
What it does not show yet
The 12-month findings have so far been described in a video interview, not in a paper with full methods and tables. The registry record says results have not yet been posted there3. The figures available leave several questions open.
- Who is in the one-year group. Only men who responded in the first 6 months moved on to the second part3. The year-long numbers therefore describe men who were already doing well, not every man who started.
- The comparison. The 2.39% figure is a change from each man’s own starting point1. The available sources do not give the matching figure for responders who were switched to the dummy solution, so the size of the difference between groups at one year cannot be judged from them.
- What 2.39% means in the mirror. Hair density in a small measured patch is a lab-style measure. How it translates into visible change for an individual man is not described in the sources.
- Longer use. Results stop at 12 months of treatment.
Other figures circulate online. A UK hair-transplant clinic’s blog says one study of more than 700 men showed a 539% increase in hair count compared with placebo, and another a 168% improvement5. Those are relative comparisons with the dummy group, not changes from each man’s starting point, so they cannot be set directly against the 2.39% figure.
Who is behind it
The trials were run by the drug’s developer. The registry lists Cassiopea SpA as the sponsor of SCALP 23, and Cosmo Pharmaceuticals announced the trial results2. The clinic blog notes that most major studies of clascoterone for hair loss have been funded by the manufacturer, and that independent research is needed to confirm the findings5. The Dermatology Times article does not state whether Zeichner has financial ties to the company1.
Money is also riding on the field. In September, MedWatch reported that investors had sent shares of Cosmo, Veradermics and Absci higher on hopes for more effective treatments for pattern hair loss6. Veradermics’ stock had risen about 500% since its February stock market debut, and Absci’s had more than doubled this year, the outlet said6.
How it fits the field
Clascoterone is already sold as a 1% cream for acne. There it blocks hormone signals in the skin’s oil glands, which reduces oil production and inflammation1. The clinic blog says it has been approved for acne in the US, Canada, France, Australia and, in 2025, the UK5. For hair loss, the version being tested is a stronger 5% solution made for the scalp1.
Dermatology Times reported in January that, if approved, it could be the first new way of treating male pattern baldness in more than 30 years2. Zeichner’s argument is that putting a hormone blocker directly on the scalp could act on the follicle while keeping the amount of drug that reaches the rest of the body low1. He said the one-year safety findings fit earlier studies showing little of the drug is absorbed into the body1. The clinic blog draws the contrast with finasteride, a pill that lowers DHT levels across the whole body, while clascoterone acts locally5.
Zeichner went further in his conclusion:
“A drug like clascoterone 5% solution that blocks that interaction through a topical application in an effective way and a safe way without potential systemic hormone side effects means that this drug can be a foundational treatment for all patients with male pattern hair loss.”
That is his view. The same article notes that further evaluation and regulatory review are still needed1. Pattern baldness is a different condition from the autoimmune hair loss covered in Biohack’s recent story on a daily pill approved for teens with alopecia areata.
What to watch next
In January, Dermatology Times reported that the company planned to apply to regulators once the 12-month safety follow-up was finished, which it expected in spring 20262. As of the clinic blog’s May 2026 update, clascoterone was licensed only for acne5. The next steps to watch are a formal regulatory filing for hair loss, full results posted to the trial registry3, a peer-reviewed paper with the complete one-year comparison against the dummy solution, and any independent studies.
