It's no news to you or anybody else that new supplements rear their sometimes-ugly heads every day. Only a few end up being effective or even mildly effective and some are even backed up by decent scientific studies. If you really look, and I mean really look, you could find a study that in some way could supply evidence for the efficacy of any supplement.
Trouble is, the interpretation of studies is rife with potential pitfalls.
In many cases, the alleged evidence isn't always relayed clearly from the researcher to the readers, or someone who has a vested interest in the product can misconstrue it. For instance, a classic involves giving some substance to 8 post-menopausal women. After a period of time, the women reported feeling better and their Testosterone levels increased slightly. Nothing else, such as diet, training, other supplements, etc., was taken into account. Along comes some schmoe from the supplement industry.