Tribulus

Tribulus/Drug Interactions:

  • Beta-blockersBeta-blockers: Tribulus may add to beta-blocker effects due to its negative chronotropic activity in cardiac muscle (15).
  • Calcium channel blockersCalcium channel blockers: Tribulus may add to calcium channel blocker effects due to its negative chronotropic activity in cardiac muscle (15).
  • DigoxinDigoxin: A water-soluble extract of tribulus was found to have a positive ionotropic activity, thus possibly exacerbating digoxin effects (15).
  • DiureticsDiuretics: Water extract of tribulus was found to exhibit diuretic effects (16). In dogs, ether extract of tribulus fruits produced diuresis and increased renal creatinine clearance, suggesting an increase in glomerular filtration rate (17).
  • Hypoglycemic drugsHypoglycemic drugs: Based on a mouse study, tribulus may lower blood glucose levels (7).
  • Hypotensive/hypertensive drugsHypotensive/hypertensive drugs: Tribulus has been found to have a hypotensive action, and may affect hypotension/hypertension drugs (18).
  • SteroidsSteroids: Based on preliminary study and studies of combination products containing tribulus, tribulus may increase levels of steroid hormones (11; 12; 13; 14; 18).

    • Tribulus/Herb/Supplement Interactions:

  • Cardiac glycoside herbsCardiac glycoside herbs: A water-soluble extract of tribulus was found to have a positive ionotropic activity, thus possibly exacerbating the effects of cardiac glycoside herbs (15).
  • DiureticsDiuretics: Water extract of tribulus was found to exhibit diuretic effects (16). In dogs, ether extract of tribulus fruits produced diuresis and increased renal creatinine clearance, suggesting an increase in glomerular filtration rate (17).
  • Hypoglycemic herbsHypoglycemic herbs: Based on a mouse study, tribulus may lower blood glucose levels (7).
  • Hypotensive/hypertensive herbsHypotensive/hypertensive herbs: Tribulus has been found to have a hypotensive action, and may affect hypotension/hypertension herbs (18).
  • SteroidsSteroids: Based on preliminary study and studies of combination products containing tribulus, tribulus may increase levels of steroid hormones (11; 12; 13; 14; 18).

    • Tribulus/Food Interactions:

  • Insufficient available evidence.

    • Tribulus/Lab Interactions:

  • Luteinizing hormoneLuteinizing hormone: Tribestan? may increase the levels of luteinizing hormone in males (19).
  • Serum glucose levelsSerum glucose levels: Based on a mouse study, tribulus may lower blood glucose levels (7).
  • Steroid hormonesSteroid hormones: In a clinical trial, a tribulus-containing supplement mixture resulted in significantly increased serum levels of androstenedione, free testosterone, estradiol, and DHT (14). In separate clinical studies, tribulus-containing supplement mixtures had no effect on serum testosterone, free testosterone, or PSA, although serum androstenedione, dihydrotestosterone, estrone, and estradiol were increased (11; 12; 13). .