extract (Adiantum capillus-veneris) in a testosterone-induced alopecia albino mouse model demonstrates higher follicular density and anagen:telogen ratios in groups treated with topical FNS.9 In humans, topical FNS application for the treatment of AGA was first conducted twenty years ago by Mazarella et al in an attempt to analyze its efficacy and safety.10 In the past five years, emerging evidence suggests that topical FNS may be a promising treatment with a less severe side effect profile compared to systemic therapy. This review will provide a summary of past and current clinical studies investigating topical FNS therapy for AGA.
METHODS
A primary literature search was conducted using PubMed/MEDLINE, Embase, PsycINFO, TRIP Cochrane Library, and Cochrane Skin databases with search terms“[topical finasteride], [finasteride solution], [finasteride liquid], [finasteride foam], and [finasteride cream]”. Given the focus of this article is the clinical application of topical FNS in humans, only studies regarding human in vivo topical FNS treatment efficacy were reviewed for inclusion; clinically relevant systematic reviews, randomized controlled trials, and open studies were considered. Inclusion criteria were studies involving at least one treatment group with topical FNS, inclusion of results regarding efficacy of topical FNS, and the use of in vivo treatment only. Excluded studies included those that were not written in English, involved treatment with oral FNS only, and those that addressed only the mechanism or pharmacodynamics of the topical FNS. Included studies were graded using the Oxford Center for Evidence-Based Medicine 2011 Levels of Evidence.
RESULTS
119 articles were found using the methodology outlined above. Of these, 67 records were identified by title, and further narrowed to seven records after inclusion criteria were applied and duplicates were removed. Of the reviewed articles, six were published in the last eight years, while one was published 20 years ago, and include five RCTs and two prospective studies. Three studies compare topical to oral FNS, two compare topical MNX to a topical combination of MNX and FNS, one compares combination topical treatments containing FNS, and one compares varying doses and frequencies of topical FNS application. A total of 256 (24 female, 232 male) human subjects were studied (Figure 1, Table 1).
