How to get rid of man boobs?

Hey, I'm a 16 year old guy and I have man boobs. I've been working out for the past six months mostly doing cardio stuff like running, but it hasn't really helped with the man boobs problem that much. I've tried upper body excercises too but again not much change. My health teacher said that it could be because i have a higher level of estrogen than most other guys. Another factor that led her to say that is that I don't have as much facial hair as the other guys in my class. I was wondering if there was any way that I could control that. Any vitamins that could help me reduce the estrogen levels? Any other excercises i could do that would help more. If you're an expert and wouldn't mind helping me out and would like to leave your email address that would be awesome or just an answer here would be good too. Thanks