Topical Minoxidil Therapy for Hereditary Male Pattern Alopecia

A study conducted over 32 months with 777 male patients investigated the effects of 2.8% topical minoxidil on hereditary male pattern alopecia. Of the 133 patients followed for six months or more, 45% experienced new hair growth, ranging from vellus to terminal hair. Longer treatment durations and type I or II alopecia were associated with better outcomes. Patients' subjective evaluations of hair growth were more positive than objective assessments. No serious systemic side effects were reported, though one case of allergic contact dermatitis occurred. The exact mechanism of hair growth was unclear but might have involved vasodilation or direct cell stimulation.