Clascoterone (Breezula)
Clascoterone is a topical androgen-receptor antagonist. It is FDA-approved as Winlevi (1% cream) for acne and is in late-stage trials as Breezula for androgenetic alopecia. It locally blocks DHT at the follicle and sebaceous gland while being rapidly metabolised to spare systemic androgen signalling.
01 Overview
Clascoterone is the first topical anti-androgen approved for acne in both sexes, a notable milestone because prior AR blockers (spironolactone, cyproterone) act systemically. Its scalp formulation, Breezula, has shown hair-count improvement in mid-stage alopecia trials.
Because it is hydrolysed to the inactive cortexolone after acting locally, systemic androgen blockade is minimal, giving it a cleaner endocrine profile than oral anti-androgens.
02 Mechanism
Competes with DHT for the androgen receptor in sebocytes and hair follicles, reducing sebum production and androgen-driven miniaturisation. Rapidly metabolised to cortexolone, limiting systemic AR antagonism.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Acne (approved) | 1 %/day | Transdermal | 1% cream applied twice daily (Winlevi) |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Reduced acne lesionsLowers inflammatory and non-inflammatory acne counts in approved use. | Significant vs vehicle | Clinical | |
| Increased scalp hair countImproved target-area hair count in androgenetic alopecia trials. | Modest in Phase 2 | Clinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Local skin reactionsErythema, scaling, dryness or itching at the site. | Mild | Common | Clinical | |
| HPA-axis suppression (high-dose)Transient, reversible cortisol suppression seen at large treated areas in trials. | Moderate | Uncommon | Clinical |