Does tribulus terrestris extract work?
Though tribulus terrestris has long been a constituent in tonics in Indian ayurveda practice, it is now a popular herbal nutritional supplement that is marketed as an ingredient to produce large gains in strength and lean muscle mass in people who engage in resistance training or weight lifting.
Commonly sold in dietary supplements as tribulus terrestris extract, many people ask themselves whether or not tribulus terrestris actually work to help athletes to promote gains in strength or lean muscle mass?
A recent study, published in the Journal of Strength and Conditioning Research, studied the effects of Tribulus terrestris extract on muscular strength, body composition, and urinary T/E (testosterone/epitestosterone) ratio in elite Australian male rugby players.
Dosage of tribulus terrestris used in study:
Tribulus terrestris extract – 450 mg/d or placebo capsules were consumed once daily for 5 weeks.
Note: All subjects performed structured heavy resistance training as part of the club’s preseason preparations.
Is Tribulus Terrestris a waste of money?
“It was concluded that T. terrestris did not produce the large gains in strength or lean muscle mass that many manufacturers claim can be experienced within 5-28 days. Furthermore, T. terrestris did not alter the urinary T/E (testosterone/epitestosterone) ratio and would not place an athlete at risk of testing positive based on the World Anti-Doping Agency’s urinary T/E ratio limit of 4:1.”
From the previously cited study, the authors basically concluded that supplementation with tribulus terestris extract had no effects on testosterone levels, increasing strength, or improving lean muscle mass.
Tribulus Terrestris Side Effects:
Though most sources suggest that side effects from tribulus terrestris supplementation are mild and include possible upset stomach along with gynecomastia, there have been serious reports in the literature of nephrotoxicity or kidney toxicity in males using the supplement 
Bottom line about tribulus:
The results of this study are consistent with the results of a previous study which was published in the International Journal of Sports Nutrition and Exercise Metabolism (Antonio et al, 2001), which concluded, “supplementation with tribulus does not enhance body composition or exercise performance in resistance-trained males.”
On that note, much like ZMA, tribulus terrestris appears to be another sports supplement that’s basically a waste or money for those who’re looking for performance benefits.
- Rogerson S, Riches CJ, Jennings C, Weatherby RP, Meir RA, Marshall-Gradisnik SM. The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players. J Strength Cond Res. 2007 May;21(2):348-53.
- Antonio J, Uelmen J, Rodriguez R, Earnest C. The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males. Int J Sport Nutr Exerc Metab. 2000 Jun;10(2):208-15.
- alasaz AH, Abbasi MR, Abkhiz S, Dashti-Khavidaki S. Nephrol Dial Transplant. 2010 Nov;25(11):3792-3. Epub 2010 Jul 28.