Pyrilutamide (KX-826)
Pyrilutamide (KX-826) is a topical non-steroidal androgen-receptor antagonist in clinical development (Kintor Pharmaceutical) for androgenetic alopecia and acne. Despite ongoing trials, it is already widely sold on the grey market, where quality and effective dosing are unverified.
01 Overview
Pyrilutamide is designed as a topical-only AR blocker to reduce DHT-driven follicle miniaturisation without systemic anti-androgen effects. Phase 2 and Phase 3 trials in China and the US have produced mixed results, with some endpoints missed, so its clinical status remains unsettled.
Ahead of any approval, powder and pre-mixed solutions circulate through research-chemical channels. Human efficacy and safety data are still emerging, so it sits between preclinical promise and anecdotal use.
02 Mechanism
Competitively antagonises the androgen receptor in scalp follicles, blocking testosterone/DHT signalling that drives miniaturisation, with intended rapid local metabolism to spare systemic androgen action.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Trial/anecdotal | 0.5–1 %/day | Transdermal | Trial solutions ~0.5%; forum users often 1% once or twice daily |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Increased hair countSome Phase 2 data show hair-count improvement over placebo, though later trials missed key endpoints. | Modest in trials | Clinical | |
| Local androgen blockadeBlocks AR at the scalp without meaningfully lowering serum androgens in study designs. | Follicle-localised | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Application-site dermatitisErythema, itching, or dryness where applied. | Mild | Common | Clinical | |
| Uncertain systemic anti-androgen effectLong-term systemic absorption effects are not established in the general population. | Moderate | Unknown | Unconfirmed |