Minoxidil (Rogaine). Over-the-counter minoxidil comes in liquid, foam, and shampoo forms. To be most effective, apply the product to the skin of the scalp once a day for women and twice a day for men. Many people prefer the mousse that is applied when the hair is wet.
Minoxidil products promote hair growth or decrease the rate of hair loss in many people, or both. At least six months of treatment are needed to prevent further hair loss and to regrow hair. It may take a few more months to determine if the treatment is effective for you. If it's helping, you'll need to keep using the drug indefinitely to maintain the benefits.
Possible side effects include scalp irritation and unwanted hair growth on the surrounding skin of the face and hands.