What Percent of Your Propecia Patients Find Lumps in their Chests?

Dear Dr Rassman, thanks again for the great blog and thoughtful responses.

Afraid I have yet another propecia related inquiry! I noticed in a recent post you informed another reader that there have been cases of your patients on propecia developing lumps in the breast region and that your are now working with another Dr to treat this side effect.

While I’m aware these are not necessarily related to their propecia course I was wondering if you could give an approximate indication of what percent of your patients have suffered this side effect?

Many many thanks again

I believe what you are referring to is gynecomastia (enlargement of breast tissue). They are not necessarily “lumps”. I believe the reported incidence is about 1 in 300 to 1 in 700 or so. In my clinical practice I think the incidence is lower.