Finasteride

hormone · endocrine · reproductive · integumentary · Oral

Finasteride, a hormone. 4-Azasteroid competitive inhibitor of 5α-reductase type II (dominant in prostate, seminal vesicles, scalp follicles).… Oral half-life 6 h.

4-Azasteroid competitive inhibitor of 5α-reductase type II (dominant in prostate, seminal vesicles, scalp follicles). Blocks conversion of testosterone → dihydrotestosterone (DHT). ~70% serum DHT suppression at 1 mg/d; higher suppression at 5 mg in prostatic tissue. Does not affect testosterone or estradiol levels. Does not cover type I isoform (sebum, liver) — dutasteride inhibits both.

Pharmacokinetics

• Oral — t½ 6 h · F 65% · ka 1.36 h⁻¹ · Vd 77 L

Related compounds

• Testosterone (TRT) — synergistic
• Dutasteride — warn

Sources: PMID:8846625, PMID:8562856, PMID:9605412, PMID:19922895, PMID:7679063