Evidence-based treatments for female pattern hair loss: a summary of a Cochrane systematic review

Female pattern hair loss (FPHL) or androgenic alopecia is the most common type of hair loss affecting women with reduced hair density and can have a serious psychological impact. It is characterized by progressive replacement of slow cycling terminal hair follicles by miniaturized, rapidly cycling vellus hair follicles. The frontal hair line may or may not be preserved. The aim of this review was to assess the evidence for the effectiveness and safety of the treatments available for FPHL. Searches included: Cochrane Skin Group Specialised Register, Cochrane Central Register of Controlled Clinical Trials in The Cochrane Library, MEDLINE, EMBASE, AMED, PsycINFO, LILACS and several ongoing trials registries (October 2011). Randomized controlled trials in women with FPHL were identified. Twenty-two trials, comprising 2349 participants, were included. A range of interventions was evaluated, with 10 studies examining varying concentrations of minoxidil. Pooled data from four studies indicated that a greater proportion of participants treated with minoxidil reported a moderate increase in their hair regrowth compared with placebo (relative risk 1·86, 95% confidence interval 1·42-2·43). There was no difference between the number of adverse events experienced in the twice daily minoxidil and the placebo intervention groups, except for a reported increase with minoxidil 5% twice daily. Single studies accounted for most of the other comparisons, which were assessed as either having high risk of bias and/or they did not address the prespecified outcomes for this review and provided limited evidence of either the effectiveness or safety of these interventions. Further well-designed, adequately powered randomized controlled trials investigating other treatment options are still required.