Finasteride and androgenic alopecia; from therapeutic options to medical implications

Androgenic alopecia (AGA) is an esthetic condition with varying psycho-social implications, easily accepted by some patients and tolerated only with difficulty by others. Modern therapeutic options such as 5α-reductase inhibitors have significant outcomes, but also exert significant side effects in a subset of patients. The literature describes three distinct situations regarding finasteride administration, a compound largely used for AGA. Some studies show finasteride to be very safe with minimal or no side effects. Other studies take a more cautious approach, recognizing such side effects but, at the same time, considering the putative relationship between finasteride and adverse effects to be disputable, given that placebo administration in AGA is associated with relatively similar or even more severe side effects. Finally, some authors/studies are concerned that, when compared to placebo, finasteride administration may result in side effects with greater frequency and severity, and sometimes that persist even after treatment cessation in the form of post-finasteride syndrome. Several factors presented in this paper appear to explain finasteride inconsistency regarding its therapeutic and side effects. Such factors should be further investigated and used to categorize subjects into distinct subgroups, either predisposed to adverse reactions or more tolerant of the finasteride administration.