Some have compared the tonic properties of Tribulus terrestris to the effects of ginseng, but these occur due to entirely different mechanisms. It is also claimed that Tribulus terrestris increases testosterone by increasing gonadotropin-releasing hormone with gonadotropic adaptogen compound contained in Tribulus terrestris (GnRH) which in turn stimulates the production of LH and follicle-stimulating hormone (FSH). Testosterone, besides its role in muscle-building and raising fertility and libido, is known to have a positive effect on bone marrow activity (for red blood cell production) and the immune system.[citation needed]
Animal studies in rats, rabbits and primates have demonstrated that administration of Tribulus terrestris extract can produce statistically significant increases in levels of testosterone, dihydrotestosterone and dehydroepiandrosterone,[7] and produces effects suggestive of aphrodisiac activity.[8] On the other hand, one recent study found that T. terrestris caused no increase in testosterone or LH in young men,[9] and another found that a commercial supplement containing androstenedione and herbal extracts, including T. terrestris, was no more effective at raising testosterone levels than androstenedione alone.[10]
The active chemical in T. terrestris is likely to be protodioscin (PTN),[11] a cousin to DHEA. In a study with mice, Tribulus was shown to enhance mounting activity and erection better than testosterone cypionate.[citation needed] This however, is not as convincing as one might think. Although an OTC supplement outpacing a pharmaceutical is big news, testosterone cypionate is a synthetic ester of testosterone engineered for its longer activity. To be effective, its level must build up in the system of the animal using it. This process usually takes 2???3 weeks.National Institutes of Health,
DailyMed: About DailyMed, retrieved on 2007-11-15 The proerectile aphrodisiac properties were concluded to likely be due to the release of nitric oxide from the nerve endings innervating the corpus cavernosum penis.
Tribulus terrestris - Wikipedia, the free encyclopedia
