I have gynecomastia and recently my hairline start to recede, can I take Propecia to help it?

Hello and thank you for your question about gynecomastia and Propecia. Propecia is known to raise estrogen levels in people who use it, although gynecomastia is not a known side effect of Propecia. Talk to your doctor about the cause of your gynecomastia before taking Propecia. If you cannot use Propecia, your board-certified facial plastic surgeon can recommend alternatives to address your male pattern baldness that do not involve drugs.  Hair transplantation or hair rejuvenation procedures using PRP (platelet rich plasma) which rely on your own blood to improve the appearance of your hair could be good alternative options. Good luck! 
- Jacqueline T. Cheng, MD

In my opinion, gynecomastia is a relatively rare side effect of finasteride. The original studies did not show this side effect  and only recently have a few cases been reported. However, the cause of your gynecomastia should be determined prior to starting finasteride. In addition, a hair loss expert would be able to tell you if you are a candidate for finasteride. Should you be a candidate and have idiopathic gynecomastia, then finasteride may  be a good choice.

There are many (largely anecdotal) reports of finasteride worsening pre-existing gynecomastia. Studies have looked at the risk of gynecomastia in men starting finasteride who don’t have gynecomastia to begin with. Most men with gynecomastia to begin with are excluded from these trials so we don’t have good data on how gynecomastia worsens in finasteride users. Finasteride raises estrogen levels and mechanistically and pathophysiologically it would make sense that that small increase in estrogen could trigger hyperplasia of breast tissue in susceptible men. I encourage all males with concerns about gynecomastia to discuss these issues with their physicians. Serial photography of breast tissue is essential although frequently not done.

If you presently have gynecomastia, taking finasteride will not raise your risk of making it worse, more than others your age without it.