Tribulus Terrestris extract is a herbal supplement that is claimed by supplement companies to boost testosterone, therefore helping to build muscle. It was first used as a chinese medicine for premature ejaculation.

Unfortunately, over the years multiple studies have debunked the idea of testosterone increases from Tribulus Terrestris supplementation. Bodybuilders that have taken it, usually report no boost in muscle building. Over the years, companies have tried to claim that there tribulus terrestris was superior or that it contained the right form of it in the right amounts.

I think one reason why their is a strong belief that Tribulus Terrestris increases testosterone, is because most notice an increase in libido and erections with Tribulus. Most had previously thought this was probably due to an increase in LH stimulating testosterone production, but a study showed the real cause. A rabbit study published in Ann Acad Med Singapore. 2000 Jan;29(1):22-6 showed that tribulus causes a release of nitric oxide in the body. Viagra works on nitrix oxide too. Nitrix oxide causes improved blood flow to the penis and the rest of the body by vasodilation. A study done on rats Life Sci. 2002 Aug 9;71(12):1385-96 showed increased mounting activity from it’s use.

It appears that Tribulus Terrestris may be a good sexual health drug, but for building muscle it is unlikely to help.