Finasteride is a popular medication commonly known by the trade names Proscar and Propeica that is defined as a 5alpha-reductase (5-AR) inhibitor. By its nature, Finasteride combats symptoms brought on by the type 2 5-AR enzyme which by its nature is responsible for the conversion of Testosterone into Dihydrotestosterone (DHT). Make no mistake, this is a medication that while often viewed as quite simplistic should not be taken without caution. At any rate, Finasteride can protect and combat common DHT related issues that may occur, such as Hair-Loss, Prostate Enlargement and Prostate Cancer.
Of course, as you're a human being you naturally produce testosterone, and as such there will be a conversion into DHT. The rate of conversion will vary tremendously from man to man, but it will occur nonetheless. Then we have anabolic steroid users, and a large portion of the anabolic steroids we have at our disposal are of a DHT nature, and for the steroid user, this is where Finasteride can prove to be very useful. Even so, it must be stated the vast majority will not need Finasteride or any such protection. Those who are not predisposed to male-pattern baldness will not have hair issues to begin with, and those who have a healthy prostate, do not abuse steroids or cause any other related stress to the prostate will in most cases never need the first batch of Finasteride.
The reasons any one would take Finasteride are pretty obvious as there's really only two; to combat hair-loss and prostate issues. Hair-loss is the most common reason anyone uses Finasteride, and this includes steroid users and non-users. Through use, the individual can prevent further hair-loss and in about half the cases spur new growth through steady medication. Then there's the issue of an enlarged prostate, and with 6 months of therapy, (sometimes more) the enlargement can be reversed, and all will be as it once was.
Finasteride is not a bed of roses, and as a potent androgen suppressor, (DHT is an androgen) it can lead to many unwanted problems. If you use Finasteride, you will severely diminish muscle hypertrophy, and this is an issue that is often left ignored; after all, so many are so concerned with hair. Such an effect can have a negative impact on our physical well-being as well as our sexual function. Make no mistake, we're not saying these side-effects are assured, they are simply possible, but the adverse Finasteride side-effects carry a greater probability than most of those related to anabolic androgenic steroids.