The mechanism by which Tribulus terrestris improves erectile function may involve an enhancement in the relaxation of penile smooth muscle tissue, increased intracavernous pressure, and elevated penile blood flow. These effects seem to be dependent on a greater release of nitric oxide (NO) from the endothelium of blood vessels.[1][2][3]
Tribulus terrestris and its extracts may also have antioxidant and anti-inflammatory properties in vitro. Tribulus terrestris scavenges hydrogen peroxide and superoxide free radicals[4] and increases the activity of the antioxidant enzyme superoxide dismutase.[5] Furthermore, Tribulus terrestris might inhibit the production of inflammatory cytokines, including TNF-𝛼, interleukin 6, and interleukin 10.[6]