Glycine

About Glycine

Glycine is the simplest amino acid, with a single hydrogen atom as its side chain, and the only common amino acid that is not chiral. It was first isolated in 1820 by Henri Braconnot from gelatin, and its name comes from the Greek glykys, meaning sweet, after its taste. The body makes glycine mainly from serine, but it is considered conditionally essential because synthesis may not always meet demand. Glycine makes up about one third of the residues in collagen, occupying every third position of the triple helix, and it is a building block for glutathione, creatine, heme, and purines. It is an inhibitory neurotransmitter in the spinal cord and brainstem and a required co agonist at NMDA receptors. Small studies have examined glycine for sleep quality and metabolic health, and a modest lifespan extension was reported in mice in the Interventions Testing Program of the National Institute on Aging. Glycine combined with N acetylcysteine, known as GlyNAC, has been studied in older adults. Gelatin, bone broth, meat, and fish are rich sources.