Epristeride
Epristeride is a selective, non-competitive (uncompetitive) type II 5-alpha-reductase inhibitor used mainly in parts of Asia for benign prostatic hyperplasia. Unlike finasteride it inhibits the enzyme by a different mechanism, and it has been explored for androgenetic alopecia.
01 Overview
Epristeride reduces DHT production by binding the enzyme-NADP complex, an uncompetitive mechanism distinct from finasteride's. It is marketed in China and some Asian markets for BPH and has limited study in hair loss.
Human data outside BPH is sparse, so its role in alopecia is not well established despite a plausible mechanism and generally mild side-effect profile.
02 Mechanism
Uncompetitively inhibits type II 5-alpha-reductase by binding the enzyme-NADP+ complex, lowering conversion of testosterone to DHT without competing at the substrate site.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| BPH | 10–20 mg/day | Oral | 5-10 mg twice daily in BPH use |
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Reduced DHT / prostate volumeLowers serum DHT and improves BPH symptoms. | Moderate | Clinical | |
| Possible hair-loss benefitPlausible for androgenetic alopecia but with little direct human evidence. | Unclear | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Sexual dysfunctionReduced libido or erectile difficulty, generally milder than finasteride reports. | Mild | Uncommon | Clinical | |
| Fetal risk on exposureAs a 5ARI, potential to affect male fetal development if a pregnant woman is exposed. | Severe | Rare | Clinical |