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 10mg of extract per kilogram of body weight for four weeks did not increase their androgen levels relative to placebo users.
Enhance exerise performance
From a clinical trial published in the “International Journal of Sports Nutrition and Exercise Metabolism,” supplementation with 3.21mg of tribulus terrestris extract per kilogram of body weight for eight weeks did not enhance body composition or exercise performance in resistance-trained males. Overall, tribulus terrestris has not been studied extensively for enhancing athletic performance.
Side effects
There are few reported side effects of tribulus terrestris supplementation in the literature. Some users of this extract report minor side effects including stomach upset which may be relieved by taking it with food. Gynecomastia or breast enlargement occurs in males when they develop abnormally large mammary glands. Changes in the levels of androgens and estrogens or how your body responds to these hormones can result in gynecomastia. According to a case report in the journal “Breast,” a young weight trainer developed gynecomastia after oral consumption of tribulus terrestris. Though this is a rare side effect, it is important to be aware of before you consider supplementation with tribulus terrestris extract.
About this Author
Dr. Jarret Morrow received his Doctor of Medicine and Bachelor of Science with specialization in pharmacology with distinction from the University of Alberta. Dr. Morrow has been writing for the past 10 years with publications primarily involving medical journals and clinical skills textbooks.
