Dr. Feller,
Your position is cautious but legitimate and defensable. However there is another side to the issue. We tamper with the hormonal equilibrium to a much larger degree when dht blockers are used to treat benign prostatic hypertrophy. Perhaps in this case the benefits outweigh the risks, whereas the benefits of incremental hair growth does not outweigh the risk. This is a judgement call for sure. I am not aware of any current evidence of risk beyond the adverse effects mentioned in the drug insert (significant as they are). The FDA has looked at the evidence and finds the drug safe and effective for its intended use. Of course, new evidence could surface over the years and that opinion could change. Also, in contrast, the hormonal manipulation that women endure for birth control, menstrual pain, fertility, menopause, etc. is on a totally different scale than dht blocking- synthetic hormone analogs, horse estrogen, etc. The calculus is different because it is used for vastly different reasons, but we do have a decades long medical legacy of hormonal manipulation- for better or worse.
Tom Spruill, M.D.