Measurable Success with Half Dose of Propecia?

Dr. Rassman,

I have read on your blog that .5 mg of propecia once daily is believed to be 80% as effective as the recommended dosage of 1 mg.

With that being said, in your clinical practice, are you aware of any patients showing clinical or measurable improvement when taking only a .5 mg dosage of propecia once a day? In other words, what are your experiences in practice with taking this minimal dosage due to side effects?

Most of my patients take the recommended 1mg of finasteride. There are a minority of patients who take 0.5mg of finasteride, because they’ve reported side effects or believe they just want to be on a maintenance regimen. While the 0.5mg dose is not an approved dose for hair loss, the reports show it is 70 to 80% as effective as the full 1mg dose. This is difficult to impossible for me to verify, though. To answer your question more specifically, I would need access to the studies done when the dose when optimized by Merck. I don’t have enough experience with the 1/2 dose to tell you more.