Never heard of 1mg m1t pills. I have seen a lot of 10mg. pills. But as for your question, 18 is way to young to use any steroids. Many problems can occure; permenently stunted height, prmanantly messed up endocrine system, to name a few. M1t is a potentially dangerous drug for anyone to take regardless of age. If he took 11 10 mg. pills he will be hearing from his liver shortly. Tell him to do some research before he starts taking dangerous drugs at 18.