OH-flutamide is the active metabolite of flutamide which is perhaps the most popular oral anti-androgen with the shortest half-life. Orally flutamide can be taken up to 750mg per day and it can be moderately liver toxic at such high dosages. OH-flutamide, however, is much less liver toxic and has great potential for hairloss. It has the shortest half-life of all FDA approved drugs. Its half-life is around 5-6 hours but due to its weaker binding affinity than testosterone, it causes almost no effects unless present in much higher concentrations than testosterone. For this reason, it can be used in the scalp to produce a local effect but cause minimal systemic side effects. Typically scalp absorption peaks at around 16 (depending on the study and vehicle) hours providing for relatively sustained release of the drug applied Not many people studied into flutamide enough to know that OH-flut is actually the active component of the drug and can only be converted by the liver. Flutamide in its base form is almost inactive compared to OH-flutamide HOWEVER a few studies for hairloss actually compared flutamide in its base from topically with finasteride. This study actually showed that flutamide in its base form topically was slightly more effective than finasteride when used topically which begs the question, just how effective would OH-flut have been... Additionally, studies have shown that it's able to decrease prostate weight by more than finasteride which means it was able to reduce androgenic gene expression to a greater extent. Thus we can conclude that it will be more effective than finasteride for hair loss. Unlike RU58841 OH-flutamide is actually the active metabolite of an FDA approved drug and its risks and side effects are very extensively researched. There is no worry of cardiotoxicity or potentially being carcinogenic with OH-flut as is often a cause for concern with RU58841 Anecdotally speaking, I have suggested topical bicalutamide to a few people and 3/4 of them reported great success up to 12 weeks whereas they were not fully responding to finasteride. They since have not logged back into these forums so I haven't been able to follow up with them, but I'm going to assume they're doing great and living their lives. Bicalutamide, however, has a ~6 day half life making topical treatment very difficult due to the systemic build up. OH-flut is essentially the shorter twin to bicalutamide as it has a half-life of around 6 hours making topical use much more realistic. From this we can theorize that OH-flut topically possibly can be an effective and potentially better treatment than finasteride for hairloss and it may even be helpfull for those who are unfortunate enough to not fully respond to finasteride. As far as dosage, it would most probably require at most 100-150 mg per day for full scalp coverage.