What It Is
Minoxidil belongs to a class of medicines called vasodilators. It is best known as a solution or foam applied to the scalp, and it is also available as tablets.
What It's Used For
Topical minoxidil is generally used to treat pattern hair loss in men and women (androgenetic alopecia). It helps slow further hair loss and can stimulate regrowth in some people. Results usually take several months, and hair loss tends to return if treatment is stopped. Minoxidil tablets were originally developed for severe high blood pressure.
How It Works
Minoxidil widens blood vessels by opening potassium channels in smooth muscle. How it promotes hair growth is not fully understood, but it is thought to extend the growth phase of the hair cycle and enlarge shrunken hair follicles, possibly by improving blood supply to the follicle.
History and Regulatory Status
Minoxidil was developed in the 1970s as a blood pressure tablet, when doctors noticed that patients grew extra hair. It was approved as a topical hair-loss treatment in the late 1980s. Topical forms are sold over the counter in many countries, while tablets are prescription medicines. Low-dose tablets are now also used by some doctors for hair loss.