L-threonine (threonine) is an essential amino acid (which can't be produced in the body) that helps to maintain the proper protein balance in the body. It is important for the formation of collagen, elastin, and tooth enamel and enhances the immune system by aiding in the production of antibodies.
L-threonine supplements are available in capsules and as bulk powder.
L- threonine is a precursor of the amino acids glycine and serine, which have effects on the central nervous system. Glycine acts as a neurotransmitter in the central nervous system (CNS). Glycine and gamma-aminobutyric acid (GABA) are the major inhibitory neurotransmitters in the CNS. Glycine also appears to enhance the activity of the N-methyl D-aspartate (NMDA) receptor complex in the brain, which is involved in memory and learning. Dysfunctions of NMDA receptors seem to play a crucial role in the neurobiology of disorders such as Parkinson's disease, Alzheimer's disease, epilepsy and ischemic stroke.