I am quite a beginner, I first worked out without taking any supplements. For about 6 months I take a whey protein shake after training, and whenever I feel my muscles the days after training.
I read in a book about genes a sentence that many guys on high school take steroids after training to get faster results. But it has a side effect that your testosteron level becomes very low or so. Is taking protein shakes bad for your body in any way???