1) Expecting it to be an effective aromatase inhibitor in man when taken orally -- it isn't,2) Mistake in the research being done in mistaking 6-OXO or more likely its metabolite 6-oxotestosterone as being testosterone, thus yielding wrong marketing claims that it increases testosterone, and3) The completely "off" theory that it really does decrease estrogen despite test results showing no change.What 6-OXO is, is a poor prohormone.