Taurine is a conditionally essential amino acid created from methionine and cysteine. It occurs in the body as a free amino acid or as a component of simple peptides – in platelets and bile, where together with the bile acid it forms taurocholic acids. This amino acid is not a building block of systemic proteins, but it is necessary in their transformation process. The human body produces small amounts of taurine, but they are not sufficient, especially for young and growing bodies, and the bodies of physically active people. Just like glutamine, taurine stores nitrogen in the body. During exercise, the body produces and releases excessive amounts of serotonin – a hormone that causes catabolic reactions in the muscles. Taurine limits the production of this hormone. A decreased amount of serotonin prevents weariness and allows a person to exercise much longer. During physical effort, taurine maintains a long-lasting high concentration of calcium ions in the nervous system and muscle cells.