I can find numerous scientific studies as well as bloodwork from users to show otherwise. If however, you argument is that they don't raise testosterone to a level capable of causing a physiological change, then you may indeed be correct. But that is for another thread...not to derail this one.
Even so, in situations where someone has low T, borderline low T, or in a PCT scenario, they are golden. I've personally had success running multiple natty test boosting cycles, though imo the length at which they need to be ran to see body comp chances is about 12 weeks.