I thought testosterone is testosterone? Isnâ??t that what they say on the internet? If you hear it on a steroid forum, isnâ??t it true? Well, research dating as far back as 1954 says no. In fact, (primate) research as recent as this decade seems to say the same thing. Alright, I can hear the pubmed-scientists and keyboard-cowboys all over the internet shouting in protest right now. I know that primate studies arenâ??t perfect, but theyâ??re offering us a clue as to why we all gain more weight on the longer esters versus the shorter esters. And in this case, they offer us a perfect- even elegant â?? explanation.