Tribulus terrestris, a flowering plant native to warm and tropical regions, is known by other names including puncture vine, yellow vine, and goat head among others. The extract is found in many common dietary supplement products with claims of increasing testosterone levels and thereby helping to build muscle and improve sexual performance. Though there is little evidence regarding the effectiveness of this extract, it is still widely used by many athletes.
Increase Muscle Mass
According to a study published in “The Journal of Strength and Conditioning Research,” elite male rugby players who supplemented with 450 mg/d of tribulus terrestris extract for five weeks did not experience large gains in strength or muscle mass. In addition, the testosterone levels as measured by urinary excretion of the test subjects did not differ significantly from placebo users.
Increase Testoserone Levels
Another of the putative effects of supplementation with tribulus terrestris exract is that it is claimed to boost testosterone levels. Tribulus terrestris extract contains steroid saponins which were thought to mediate this effect. From a study published in “The Journal of Ethnopharmacology,” young males who consumed 20 or 10 milligrams of extract per kilogram of body weight for four weeks did not increase their androgen levels relative to placebo users.