IMO, i bearly started on AS at 180lbs natty pounds, see u gotta have a strong foundation first of all, or u might collapse, cuz i agree that 150lbs its way way too small to start on AS, shit when I was at 150lbs i wouldn even bother to learn about AS, I put all my mind into correct form,training hardcore,and specially the hard diet a bodybuilder has to follow, just ask ur self when u do end up doing AS if u already master ur diet and training,cuz u gonna flip out when them drugs start kicking in and ur small frame wont be ready for it!!!