Labelled analogue of L-Vailne. L-Valine is an essential amino acid and one of 20 proteinogenic amino acids. L-Valine cannot be manufactured by the body and must be acquired through diet or supplementation. L-valine is found in grains, dairy products, mushrooms, meats, peanuts and soy proteins. L-Valine has been used in studies to attenuate arrhythmias and induce hypotensive effects.