Clascoterone (Breezula) — Topical AR Antagonist — Supplements
First-in-class topical androgen receptor antagonist for AGA; Phase 3 SCALP trials completed Dec 2025 with significant TAHC improvement vs vehicle; FDA/EMA filing expected mid-2026.
Overview
Clascoterone (Breezula, developed by Cosmo Pharmaceuticals/Cassiopea) is a first-in-class topical androgen receptor (AR) antagonist currently in late-stage development for androgenetic alopecia (AGA). Unlike all existing AGA pharmacotherapies, which either act systemically (finasteride, dutasteride, spironolactone) or work through non-androgen pathways (minoxidil), clascoterone blocks DHT directly at the androgen receptor in the hair follicle without measurable systemic absorption — addressing the root cause of AGA at the follicle level without hormonal side effects. A lower-dose formulation (clascoterone 1%, Winlevi) received FDA approval in 2020 for acne, establishing the compound's safety profile. The Phase 3 SCALP program (SCALP 1: NCT05910450; SCALP 2: NCT05914805) enrolled 1,465 men with mild-to-moderate AGA across 51 sites in the US and Europe. Topline results released December 2025 confirmed statistically significant improvement in Target Area Hair Count (TAHC) vs vehicle in both trials (SCALP 1: 5.39-fold improvement vs vehicle, p<0.05; SCALP 2: 1.68-fold improvement vs vehicle, p<0.05). The 12-month safety extension completed spring 2026; FDA/EMA submissions are expected mid-2026 with potential approval ~2027. Clascoterone will likely be the first topical androgen receptor antagonist approved for hair loss, filling a critical unmet need for patients who cannot tolerate systemic anti-androgens (particularly pre-menopausal women and men concerned about sexual side effects).
Indications
- Androgenetic alopecia (AGA) — male pattern hair loss (primary indication)
- Female pattern hair loss (FPHL) — no dedicated Phase 3 data yet but mechanism highly relevant
- AGA in patients unable to tolerate systemic finasteride/dutasteride/spironolactone side effects
- Adjunctive use with minoxidil for combined mechanism coverage (DHT blockade + anagen prolongation)
Mechanism of Action
Clascoterone is a steroidal androgen receptor antagonist that competes with DHT for binding at the androgen receptor in hair follicle dermal papilla cells. By occupying the androgen receptor without activating it, clascoterone prevents DHT-mediated transcriptional programs that drive follicle miniaturization, perifollicular inflammation, and shortening of the anagen phase
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Clascoterone 5% topical solution (Breezula — investigational) | 1 mL (containing 50 mg clascoterone) | Twice daily (BID) to affected scalp | Dose used in Phase 3 SCALP trials; not yet commercially available; compounded versions available through some pharmacies |
| Clascoterone 1% cream (Winlevi — FDA-approved for acne) | Thin layer | Twice daily to affected scalp | Off-label use; lower concentration than Phase 3 AGA trials; limited AGA-specific evidence at this concentration |
Evidence Grade
GRADE C
Safety & Contraindications
- Minimal systemic absorption — serum clascoterone levels near or below detection limits after topical application, unlike spironolactone which is substantially absorbed
- No meaningful systemic androgen suppression — does not significantly alter serum testosterone, DHT, or LH levels (key advantage over finasteride/dutasteride)
- Most common AEs in Phase 3: local skin reactions (erythema, dryness, scaling) at application site — generally mild and manageable
- No systemic anti-androgenic effects (gynecomastia, sexual dysfunction) expected based on safety extension data
- No PSA suppression — does not confound prostate cancer screening
- Not yet FDA-approved for hair loss as of February 2026 — currently available only through compounding pharmacies or international suppliers as off-label prescribing
- FDA-approved clascoterone 1% (Winlevi, for acne) can be used off-label but the 5% concentration for AGA is not yet available commercially