Finasteride is a type II 5 α reductase inhibitor. It was originally used to treat prostate diseases. It is well absorbed in the intestine. Through liver metabolism, the half-life of drug serum is 5-6 hours.
It has a more than 95% retention rate. 75% – 87% of the people have increased the number of hair in different degrees, the diameter of hair has increased, and visible appearance improvement has been achieved. Only a few people have slight side effects, about 0.7% – 1.8% of them have side effects of hypolibido, erectile dysfunction and decreased ejaculation, but 0.4% – 1.3% of the placebo group also have these side effects. The side effects decreased to less than 0.3% with the prolongation of 5 years.