Women can use ketoconazole to treat hair loss, but its main purpose is to treat fungal infections. If you have a fungal infection of the skin or nails and nothing else works, doctors sometimes prescribe ketoconazole, according to the American Society of Health-System Pharmacists. Typically, people take ketoconazole as a tablet by mouth for fungal infections. If you use it to try to increase hair growth, you use it as a topical treatment.
Women who have thinning hair may have androgenic alopecia, which is due to male hormones, called androgens. Ketoconazole has anti-androgenic effects, according to the American Hair Loss Association. It also can reduce the production of testosterone by the adrenal gland, which is one of the ways in which ketoconazole works to treat hair loss.
Ketoconazole may also inhibit the production of dihydrotestosterone. DHT is the enemy of hair follicles and tries to kill them, explains the American Hair Loss Association. Testosterone converts to DHT, which shrink hair follicles, meaning the kiss of death for healthy hair.
Because ketoconazole is an anti-fungal drug, it may work on treating hair loss by clearing up a fungal infection on the scalp. Ketoconazole reduces inflammation, which could be the reason it works to treat hair loss.
Nizoral shampoo contains ketoconazole and comes in a 1 percent and a 2 percent version. You can buy a 1 percent version of the shampoo over-the-counter, but the 2 percent version is more effective, according to the American Hair Loss Association. You need a prescription to get Nizoral shampoo with 2 percent ketoconazole.
Using ketoconazole as a topical treatment in shampoo form produces no significant side effects, according to the American Hair Loss Association. Taken as an oral tablet, ketoconazole can cause liver damage, especially if you drink large amounts of alcohol, according to the American Society of Health-System Pharmacists.
The amount of ketoconazole you would need to take orally to increase hair growth is unsafe, according to the Androgenetic Alopecia website. It is unnecessary to take ketoconazole orally to treat hair loss because you only need to target the hair follicles. Therefore, a local application in the form of a shampoo is the best way to use ketoconazole for hair loss treatment.