Tribulus terrestris is an herb that has been part of traditional medicine in India and China for centuries, but it got worldwide recognition during the 1990s when Eastern European Olympic athletes revealed they were taking tribulus to boost their performance.
Efforts to improve sports performance is a relatively new use for this herb, which traditionally has been taken for erectile dysfunction, infertility, and low sex drive. Studies conducted in Bulgaria and Russia suggest that tribulus can raise testosterone levels (by increasing luteinizing hormone), DHEA, and estrogen. Some of the active components in tribulus are called steroidal saponins (i.e., furostanol and spirostanol glycosides), which are found mainly in the leaves. Recently, scientists have discovered five additional furostanol saponins in the herb’s fruit and announced that they have antitumor properties, but the research is very preliminary. (Wang 2009)
In erectile dysfunction, preliminary studies in animals show that tribulus increased sexual behavior and pressure within the penis, changes that were attributed to a rise in testosterone. (Gautherman 2003) In a more recent study, however, men who took tribulus supplements daily for four weeks did not experience any change in their testosterone, androstenedione, or luteinizing hormone levels compared with men who did not take tribulus. (Naychev 2005)
To test claims by tribulus supplement makers that use of the herb significantly increases strength and muscle mass in 5 to 28 days, a study was conducted by Southern Cross University in Australia. (Rogerson 2007) The participants were elite rugby players, who took either placebo or tribulus once a day for five weeks. At the end of the study, tribulus use did not produce the large gains in strength or lean muscle mass that is advertised by supplement makers.
Despite the lack of scientific evidence, some men continue to take tribulus terrestris. The remedy should be taken with the advice of a knowledgeable healthcare provider. Tribulus terrestris has been known to cause an increase in breast size (gynaecomastia), although this is rare. Men who have hormone-dependent conditions are advised not to use tribulus terrestris.
Gauathaman K et al. Sexual effects of puncturevine (Tribulus terrestris) extract (protodioscin): an evaluation using a rat model. J Altern Compl Med 2003; 9(2): 237-65
Neychev VK, Mitev VI. The aphrodisiac herb Tribulus terrestris does not influence the androgen production in young men. J Ethnopharmacol 2005; 101(1-3): 319-23
Rogerson S et al. 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
Want J et al. Five furostanol saponins from fruits of Tribulus terrestris and their cytotoxic activities. Nat Prod Res 2009; 23(15): 1436-44.