This supplement uses the above-ground stems and leaves of Tribulus terrestris. Makers often standardize the extract to steroidal saponins to keep each batch consistent. Most human studies are small or show mixed results for physical performance and vitality.
Athletes sometimes take it to recover faster from workouts and feel stronger. Solid clinical trials, however, do not clearly show gains in muscle strength, endurance, or meaningful hormone shifts.
Watch for interactions with diabetes and blood pressure drugs. The plant can influence blood sugar and blood pressure in ways that are not fully mapped. Skip it during pregnancy and breastfeeding. Stop taking it at least two weeks before any planned surgery.