The use of oral minoxidil as a treatment for androgenetic alopecia (AGA) is limited mainly because of the side effects of severe and uncontrolled hypertension reported at standard doses of 10–40 mg.

The aim of this open-label, prospective, single-arm study was to evaluate the effectiveness and the safety of oral minoxidil at the low dose of 5 mg once daily in men with AGA types III vertex to V.

Oral minoxidil significantly increased hair growth, with a mean change in total hair counts + 19.23% from baseline at week 24; global photographic assessment revealed 100% improvement (increase > + 1 score), with 43% of patients showing excellent improvement.

Our results show that low-dose oral minoxidil can be considered a safe treatment for male AGA in healthy subjects, with only minor side effects of hypertrichosis (93%) and pedal edema (10%). There was no significant change in blood pressure (BP) and pulse rate (PR) at 24 weeks after treatment, with mean systolic BP decreasing by − 3.8 mmHg, mean diastolic BP decreasing by − 1.1 mmHg, and PR increasing by + 0.6/min.