dane is right gear is all a maturity thing.the people who use should be well informed about the compounds, what they do, dosages, administration, etc.but more imortantly they should have an extensive grasp on thier own body.at 17 they have no clue no matter how much experience they think they have.look at how many people are on this board are askign questions about their diet and all the little stuff.they are all well over 17 and they are still in pursuit of learning their bodies.training is a stimulus and response game.you have to have put your body through constant "trials" for yrs to know how your body reacts to certain stimuli.hell, 40 is too young if you are not adequately informed.there is no right age, but before reaching full maturation and experimenting is definately the wrong age.