Topical spironolactone is not FDA approved for androgenetic alopecia and has not had much study. Any use of topical spironolactone is off label and should be prescribed only in conjunction with a physician. Is it effective? Well, few such studies have been done but there may be some minor benefit. A 1997 study studied 60 women using 1 % topical spironolactone. A minor degree of benefit was seen. There is little doubt that topical spironolactone gets absorbed somewhat into the blood - so if one is going to use it you'll need to know everything about if from A to Z. Side effects from topical spironolactone are potentially similar to oral spirinolactone pills (albeit at a lower incidence). Men should not use spironolactone due to gynecomastia. Women should be aware of breast tenderness, mood changes, electrolyte imbalance, fatigue, dizziness, swelling, Women of child bearing age should speak to their physician about pregnancy concerns. One must never get pregnant while using spironolactone or the developing fetus could be seriously harmed. Spironolactone is a great drug when prescribed to the appropriate patient. But it needs to be respected. Topical antiandrogens do get absorbed into the blood stream. It would be unwise to think otherwise. REFERENCE Dill-Muller D, Zaun H. Topical treatment of androgenetic alopecia with spironolactone. J Eur Acad Dermatol Venereol. 1997 Sep;9(Suppl 1):31.