I’m concerned by something I’ve read at another site, which questions the effectiveness of Tribulus in raising Test levels at all. The comments I read were, "Tribulus products may elevate nitric oxide levels (similar to Viagra although using different agents). This leads to vasodilation of blood vessals in the penis and makes it easier to have an erection. Many guys thought this meant an increase in testosterone (T) was taking place. I have the info on [brand name omitted–but it wasn’t Tribex]; it is basically marketing material and not acceptable for publication. I also contacted the company about doing a study on their product and after lots of interest, communications suddenly broke down. The studies on Tribex 500 all indicate that it does not elevate T levels. It may prevent a decrease in T from chronic overtraining, but that is a big if. There are some studies that indicate it may cause an increase in LBM, but these studies have only appeared as absracts and were not well designed, so I would question their findings. the results may have been due simply to chance.
“Despite all the abstracts and at least one peer-reviewed publication showing that Tribulus does not increase LH or T, supplement companies still promote this as occurring. the number one selling Tribulus product is from Twinlab and I belive that best description I heard of it was “It is the equivalent of grass clippings.” Remember supplement companies in general market products that sell, not products that work.”
Any comments? Anyone have objective peer-reviewed studies which establish the potency of tribulus in increasing T or LH levels?