start taking supplements? Im 14.5 years old, i am turning 15 in about 19 days and was thinking of joining a gym. Im 6ft tall and weigh around 180 pounds. Ive heard rumors that you stop growning when you lift at a early age, is that true ? because ive known some people who been working out since they were 12 and they are fine till now. So when should i start going to the gym? and when should i take protein powder and other supplements ?