Evidence Level
The research on tribulus terrestris reveals a clear disconnect between marketing claims and clinical evidence regarding testosterone. Qureshi et al. (2014) published a systematic review in the Journal of Dietary Supplements analyzing available RCTs and concluded that tribulus terrestris does not meaningfully increase testosterone levels in healthy males, despite significant improvements in sexual function parameters. Rogerson et al. (2007) conducted a 5-week RCT in elite rugby players and found no effect on testosterone, DHT, or androgen ratios. In contrast, Kamenov et al. (2017) published a well-designed 12-week RCT in Maturitas showing significant improvements in sexual desire and satisfaction in both men and women at 750mg daily, independent of hormonal changes. This suggests the sexual health benefits operate through non-androgenic pathways, possibly involving nitric oxide, dopamine, or other neurotransmitter systems. Tribulus is safe and may genuinely help with libido, but it should not be purchased as a "testosterone booster."