This herbal supplement has been used for years to help increase sexual desire and even fertility in men. It helps to improve stamina for better sexual performance. Solaray's Tribulus Extract 450 mg can be taken daily to make sure you're ready when the moment happens. It's produced from the fruit of the tribulus terrestris vine, with a guaranteed potency of 180 mg or 40 percent saponins, the active compound in the fruit.