Permanent Side Effects of Propecia – Real or Not?



Hi Dr. Mohebi,

Trust you are well.

It was a pleasure meeting you in Los Angeles back in June. I had a few concerns about taking Finasteride and wanted to have your opinion before taking the medication.

I read few articles that side effects of finasteride include impotence, abnormal ejaculation, decreased ejaculatory volume, abnormal sexual function, gynecomastia, erectile dysfunction, ejaculation disorder and testicular pain of which I experienced some of them when using the medication back in 2010. It was also stated that patients have reported persisting erectile dysfunction despite discontinuing the drug. I do feel this is also the case for me at times. Do I need to consult with a Urologists?  Would taking 1/4 of the pill every other day have any impact on slowing down/ prevent the hair loss and at the same time not damage sperm quality?

I am still looking at a few dates to come back and get my hair transplant as I don’t want to depend on medications for long. I am aiming for either this Nov. or April at the latest.




The initial double blind study of Propecia (finasteride) did not reveal any evidence of permanent side effects from it.  This research was done on over 1000 patients and around the same number of people who were enrolled in placebo arm of the study. In fact it showed that the adverse effects of Propecia in people who initially experienced sexual side effects and decided to continue the medication improved over one year from the time they started experiencing the side effects.

There have been recent reports from smaller studies that focus on possible long term or permanent side effects of Propecia, The reported side effects included erectile dysfunction, lack of sex drive or even mood changes.  After reviewing the cited articles and their methodology, I was not convinced that the data was collected and documented properly.  The International Society of Hair Restoration Surgery (ISHRS) also assembled a group of hair restoration doctors to evaluate the validity of some of these reports regarding the side effects of Propecia.  The group’s evaluation did not support the claims of the new reports on irreversible side effects of Propecia.

It should be noted that, Merk & Co. Inc, pharmaceuticals now include an insert in Propecia packaging. This insert discusses the possibility of long term side effects. We also review this with our patients.   My thought is that a more significant study on a large group of people who took finasteride for a long period of time is needed to confirm the new claims.

If you have any sexual side effects such as changes in sex desire, erection or sperm count, you need to be evaluated by your primary doctor or a urologist instead of assuming that it is only a side effect of finasteride.