Glossary · 8 min read
What is clascoterone?
A first-in-class topical androgen receptor inhibitor. Same active family as the acne cream Winlevi, different strength and vehicle for hair.
Names and chemistry
Clascoterone is the international nonproprietary name. Researchers also call it CB-03-01 or cortexolone 17α-propionate. It is a steroidal antiandrogen designed to compete with dihydrotestosterone (DHT) at the androgen receptor in skin.
Cassiopea developed it. Cosmo Pharmaceuticals now owns the programme. The US FDA approved the 1% cream for acne in 2020 and classed it as a first-in-class topical androgen receptor inhibitor. The EU authorised Winlevi for acne in 2025.
Two products, two jobs
| Winlevi | Breezula (investigational) | |
|---|---|---|
| Strength | 1% cream | 5% topical solution |
| Indication studied | Acne vulgaris | Male androgenetic alopecia |
| Status Aug 2026 | Approved US / EU / others | Phase 3 complete; NDA planned 2027 |
| Typical use in trials | Face, twice daily | Scalp, twice daily |
People collapse the two names because the active is the same. The hair-loss dose in Phase 3 is five times the acne cream, in a solution built to spread on scalp rather than facial skin.
Why hair clinics care
Male pattern hair loss is driven largely by DHT shrinking follicles over years. Finasteride and dutasteride cut DHT production throughout the body. That works for many men and is the current standard — and it is also why sexual and mood side-effect conversations dominate forums.
Clascoterone tries a different route: sit on the receptor in the follicle so DHT cannot land, without needing to change circulating hormone levels. Phase 3 topline data reported vehicle-like systemic safety and no meaningful hormone-related adverse events. That is the entire commercial thesis.
Can you buy pharmaceutical clascoterone for hair?
Not as an approved hair-loss drug. Options people discuss:
- Winlevi 1% cream off-label — a clinician can prescribe it; evidence for hair at 1% is anecdotal. See our Winlevi page.
- Compounded lotions — available in some jurisdictions from compounding pharmacies. Quality, concentration, and legality vary. This is not the Cosmo product.
- Online “clascoterone 5% serums” — treat these as cosmetics unless a pharmacy label and a prescription say otherwise.
If your goal is hair you can defend with evidence this year, start with the stack on what to do now.