What is Tribulus Terrestris and does it work?

Tribulus Terrestris has been used for lots of different things over the years.  In Ancient Greece and India it was used for rejuvenation. In Eastern Europe its has been used for increased muscle strength and libido. But the real question is does it really work?

The limited number of studies looking ONLY at tribulus terrestris alone (most products on the market are NOT just tribulus) show that it is NOT effective for getting more muscles or improving exercise performance. Antonio et al. did a randomized control trial using 15 athletes performing resistance training. The dose used was 3.21mg/kg of body weight versus placebo. The trial lasted eight weeks and at the end they found NO changes in body weight, percent fat, total body water or mood states that were statistically significant between the tribulus group and the placebo group.

HOWEVER, there is some MINIMAL evidennce that Tribulus may have some benefit in patients with coronary heart disease (greater chest pain free intervals), and some MODERATE evidence of its benefits in male infertility (Tribulus increases sperm count and libido as demonstrated in a study by Prtoich et al.)

As always here are the references so you can evaluate the studies for yourself.

1. Wang, B., Ma, L., and Liu, T. [406 cases of angina pectoris in coronary heart disease treated with saponin of Tribulus terrestris]. Zhong Xi Yi Jie He Za Zhi or (Chung Hsi I Chieh Ho Tsa Chih) or (Chinese Journal of Modern Developments in Traditional Medicine) 1990;10(2):68, 85-87
2. Antonio, J., Uelmen, J., Rodriguez, R., and Earnest, C. The effects of Tribulus terrestris on body composition and exercise performance in resistance-trained males. Int J Sport Nutr Exerc.Metab 2000;10(2):208-215.
3. Protich, M., Tsvetkov, D., Nalbanski, B., Stanislavov, R., and Katsarova, M. [Clinical trial of a tribestan preparation in infertile men]. Akush.Ginekol.(Sofiia) 1983;22(4):326-329