I was taking minocycline 200mg/day as well as an antidepressant. I developed some pain under my left breast/nipple so stopped the antidepressant. I then still had the pain 1.5 weeks later so switched minocycline to doxycycline 200mg.day for acne. It is 2 weeks since the pain started and I am just taking doxycycline 200mg/day and the pain is still there.

Can tetracyclines such as doxycycline cause gynecomastia?

thanks.

pain is not a diagnosis of gynecomastia..and no, none of those drugs has the ability to cause gynecomastia, however, they all have an impact on other things like cardiac function.
Get back on your antidepressant, and call your doctor about pain under your left breast.