A relatively small component of protein (& protein sources) apart from Collagen, where L-Glycine makes up about 35%. Surprisingly though, L-Glycine's not an added component in any of the anti-wrinkle formulae around, like L-Proline tends to be, or supplements for connective tissue repair.

Instead, L-Glycine's commonly associated for treatment of hyperactivity and as a preventative measure against depression and epileptic seizures. The reason, L-Glycine's an inhibitory neurotransmitter and therefore has a calming effect on the brain and the central nervous system (CNS), which is the complete opposite of L-Tyrosine. L-Tyrosine acting as an excitatory neurotransmitter stimulant on the CNS and subsequently why it's included in "mental buzz" supplements.

Contraindications: Urinary Stones, Depletes Vitamin C.

Food Sources: Meat, Fish, Dairy, Beans.