well its not a steroid, and its not a supplement. basically its a research chemical that specifically affects androgen receptors, unlike steroids which mess with all of you hormones. sarms aka Selective Androgen Receptor Modulators. not messing with hormone levels also means they are almost side effect free. although gene transcription is a lil scary but never heard of anyone getting it. no a teenager does not and should not do sarms. at your age you have all the increased hormone levels you need. people take steroids in an attempt to get test levels back to where they were when they were teenagers. alot of young kids abuse this shit without any knowledge and get gyno, dick stops working, hairloss, and usually lose all their gains because they were doing something wrong before the steroids that prevented them from gettin the results they desired. being a teenager and having your natural body hormone levels would be like me being on steroids. lol all u need is a good routine and good diet