I am 22 and my hair is already thinning. will propecia (finasteride) work?

Probably: Propecia (finasteride) is one of two drugs that are approved by the fda for hair loss. It doesn't seem to work on women but most men see an improvement if they take it for at least 6 months. However, about 1/3 of people don't see much improvement. It also works in people who have thinning hair, not those who have lost their hair for years.