Taurine is an abundant amino acid in many animals, including humans. Relatively large amounts of taurine are found in leukocytes, heart, muscles, retinas, kidneys, bones, and liver. Taurine has antioxidant effects; it reacts with hydrogen peroxide to prevent oxidation of the cell membrane. Taurine enhances the effects of anticancer drugs, while also reducing side effects, and taurolidine, a taurine derivative, has been shown to exhibit anti-cancer effects without notable side effects in several types of cancer. Taurine aids in cholesterol metabolism by increasing the rate of synthesis of bile acids, and, thus, reduces triglyceride levels. In addition, taurine is involved in the growth and differentiation of nerve cells and is associated with some neurological disorders. Taurine aids in bone formation and prevents bone dissolution. Moreover, taurine prevents liver damage from a variety of drugs and, thus, protects the liver. Taurine is involved in the development and function of the retina and lens. It also has anti-atherosclerotic and anti-thrombotic effects that protect against cardiovascular disease. Taurine may have additional physiological functions, and warrants further investigation.