Ten men with male pattern baldness who had been treated with 2% or 3% minoxidil for at least 4 months were evaluated for any changes in scalp hair growth on and off drug. Objective assessments by hair counts showed a mean doubling of nonvellus target scalp hairs on topical minoxidil and loss of most of these recruited hairs when the drug was discontinued. Four of ten men had nonvellus hair counts off topical minoxidil that fell below baseline levels. Thus, hair growth on topical minoxidil is not sustained when the drug is discontinued.