What it is
The simplest amino acid, available as an oral powder or tablet supplement.
How it works
Acts as an inhibitory neurotransmitter via glycine receptors in the spinal cord and brainstem and as a co-agonist at NMDA receptors. Also serves as a substrate for collagen and glutathione synthesis.
Where it's used
Used as a dietary supplement marketed for sleep quality and as a component of collagen synthesis.
FDA-approved use
Regulated as a dietary supplement; recognized as GRAS for food use.
Tracking it
Glycine is oral, which makes consistency the whole game — a simple daily check-off with a reminder beats memory every time. with a half-life of about 1 hours, a dose log also lets a tracker model the relative amount still in your system between doses.
Source
Public reference
Not medical advice. This page is an educational summary compiled from public
sources for people who log what they take. It is not a recommendation to use
Glycine, a dosing guide, or a substitute for a clinician.
How we source →
Last reviewed 2026-06-11