Can someone explain if Finasteride is not anti-androgen?

Antiandrogens are compounds that block or inhibit the ability of androgens to do their job in the body. Finasteride is most certainly an anti-androgen.  It lowers levels in the blood and scalp of an androgen known as dihydrotestosterone or DHT. There are many classes of anti-androgens- including androgen receptor blockers, androgen synthesis inhibitors and antigonadotropins.  finasteride is an androgen synthesisis inhibitor through its inhibition of 5 alpha reductase inhibition.

Finasteride is an inhibitor of DHT (Dihydrotestosterone) production. This hormone is produced by Testosterone. Finasteride inhibits 5-alpha-reductase which is responsible for converting Testosterone to DHT. DHT is responsible for Male pattern baldness. At a dose of 1 mg/day, Finasteride lowers serum and scalp DHT levels by more than 60 percent. It has no affinity for androgen receptor and does not interfere with testosterone action. Hence, it is not an anti-androgen.
Thanks.

Finasteride is a competitive inhibitor of an enzyme called type 2, 5-alpha-reductase.  5-alpha-reductase converts testosterone into dihydrotestosterone, (DHT), the androgen molecule that leads to hair miniaturization in genetically susceptible follicles.  By inhibiting the conversion of testosterone to DHT, finasteride is effective in stopping ongoing miniaturization in genetically susceptible follicles.  Therefore, finasteride is considered to be an anti-androgen because it leads to lower levels of DHT.  Finasteride is not a hormone or a steroid.  Hairfin is simply a trade name for generic finasteride.

Best Regards,
Robert Reese, DO, FISHRS
Past-President:  ABHRS

At the dose of 1mg, the impact of finasteride is not significant enough to interfere with testosterone's effect on the body only the hair follicle and sometimes other areas of the body when side effects appear. I have not seen a single patient who had true anti-androgen effects on testosterone