Epimedium warms the kidneys, tonifies yang, stimulates the pituitary gland and thus the gonads and increases sperm production and motility. It also dilates capillaries and larger blood vessels, strengthens bones, improves metabolism, and exhibits a mild androgenic effect.
Tribulus has a long history of use in ancient Greece and India as a physical rejuvenation tonic. In China, it is used as a component of therapy for conditions affecting the liver, kidney, cardiovascular system, and immune system. It has also been used in Eastern European folk medicine for increased muscle strength and sexual potency.