Alfalfa extract is an herbal supplement that is derived from the leaves, sprouts, and seeds of the alfalfa plant (Medicago sativa). It has been used for various purposes, such as treating kidney conditions, bladder and prostate problems, high cholesterol, asthma, arthritis, upset stomach, and bleeding disorders. Alfalfa extract contains vitamins A, C, E, and K4; and minerals calcium, potassium, phosphorus, and iron.