I think when someone starts making their own $ and isn’t asking mommy and daddy, they can start using NATURAL test boosters. For me, that would have been about 13 but I didn’t start using supplements (creatine) until I was 15.
Since it is a natural herbal supplement, it wont hurt you to take it as a young adult but you wont see a lot of benefit. Your test levels will be peaking until your early or mid 20's so you really don't need a boost.