Safety of low‐dose oral minoxidil treatment for hair loss. A systematic review and pooled‐analysis of individual patient data

BACKGROUND low dose oral minoxidil (OM) is an increasingly used treatment for androgenetic alopecia and other types of hair loss. OBJECTIVES to analyze available data of patients treated with OM, focusing on safety and adverse effects. METHODS a search in PubMed and EMBASE was performed for studies reporting the treatment of alopecia with OM. Individual patient data available for pooled-analysis were sex, dose of OM, presence of hypertrichosis and lower limb edema. RESULTS 14 studies including 442 patients were analyzed. OM was used at doses between 0.25 and 5 mg, for 8 different types of alopecia. Hypertrichosis was observed in 24% of patients. All doses had an increased odds ratio of hypertrichosis, compared to 0.25-0.5mg (p<0.001). Pedal edema was observed in 2% and was also associated with higher doses of OM (p=0.009). Postural hypotension and heart rate alterations occurred only in 1.1% and 1.3% of the patients, respectively. Efficacy of OM could not be analyzed due to heterogeneous studies. However, 4 studies using OM for androgenetic alopecia reported a clinical response in 70 - 100% of the patients. CONCLUSIONS low dose OM is a safe and well-tolerated treatment for hair loss, presenting a lower adverse effect rate than standard doses. This article is protected by copyright. All rights reserved.