Can Propecia cause shedding after 6 months? Or is it just a sign that it is not working as well as I once thought? My hair density seemed to get better but after the 6 month mark I have noticed a big step backwards. Thanks guys for the great info.

If shedding were to occur, it generally begins upon starting Propecia and ends within a few months. If you see accelerated loss 6 months after starting the treatment, that is uncommon and might not be shedding from the medication. As for what it is, I couldn’t say with any certainty — but that is why talking to the doctor that prescribed Propecia to you is important.
If there were miniaturization studies with mapping of the scalp done prior to starting the Propecia, then this question could be answered a little better, as a new mapping would show changes since the original mapping. Baseline studies will tell you if this is an acceleration of your balding process.


There are two HairDX tests — one which shows if you carry the genes for balding, and one which suggests how sensitive you are to finasteride. The statistics on both of these are not 100%, but HairDX doesn’t provide an actual accuracy percentage that I could find. I don’t have enough experience with HairDX to know how accurate they are first hand, but I would expect they’d be as accurate as possible. There are multiple reasons why accuracy could be skewed, including data collection errors, software errors, and disease.