Patient Handout – Finasteride (Propecia)

Finasteride is a pill that decreases the production of one of the hormones associated with androgenetic alopecia, resulting in an increased amount of hair covering more of the scalp.


Men can take finasteride by mouth at a dose of 1 milligram (mg) per day. It is used to help hair growth in male pattern baldness. It may take 3 months to see the full effect. Please note that the drug is also used to treat the signs of an enlarged prostate.

Side effects

All drugs may cause side effects. However, many people have no side effects or only have minor side effects. Call us or get medical help if any of these side effects or any other side effects bother you or do not go away:

Side effects may include weakness and dizziness. Higher doses of finasteride (such as those used to treat some prostate conditions) can cause side effects including erectile dysfunction and decreased sex drive. However, such side effects are rarely seen with the 1 mg dose used to treat hair loss.

Other sider effects can include: lump in the breast, breast pain or soreness, or nipple discharge, enlarged breasts, dizziness or passing out, low mood (depression), testicular pain.

Finasteride is not safe for use in women who could become pregnant because of concerns regarding the development of abnormal genitalia in the male fetus; these women should not even touch finasteride pills.