Finasteride is a popular anti-androgen medication manufactured by Merck most commonly known as either Proscar or Propecia. Based on the progesterone skeleton, Finasteride belongs to a class of medications known as 5alpha-reductase inhibitors and as such is used for the treatment revolving around type 2 5-AR based occurrences.
This is important for performance enhancers as DHT based anabolic steroids have specific side-effects that may occur that can largely be remedied with the use of a 5-AR inhibitor such as Finasteride. As a type 2 5-AR inhibitor Finasteride was designed for the purpose of treating hair-loss, prostate enlargement, as well as prostate cancer.
Finasteride is very common among those who supplement with anabolic steroids yet fear hair-loss but there are important things you need to understand before you consider Finasteride use. As an androgen suppressor Finasteride can seriously inhibit the gains made while on cycle, severely and on that basis it is not highly recommended for on-cycle hair preservation.