Glycine
About
About Glycine
Glycine is the simplest amino acid and a conditional essential nutrient, highly depleted in modern diets. It is required for glutathione synthesis, collagen production, and one-carbon metabolism. Combined with N-acetylcysteine (GlyNAC), it has demonstrated dramatic reversal of multiple hallmarks of aging in older adults including oxidative stress, mitochondrial dysfunction, insulin resistance, and sarcopenia in clinical trials.
Science
Mechanism of Action
Rate-limiting precursor for glutathione synthesis (with cysteine); substrate for collagen biosynthesis; inhibitory neurotransmitter at glycine receptors; epigenetic regulator through one-carbon metabolism and methyl group donation; mTORC1 inhibitor at high concentrations.
Dosing
Typical Protocol
1.33 mg/kg body weight daily as part of GlyNAC protocol (approximately 9–12 g for average adult); 3–5 g before bed for sleep and GH support.
⚠ Protocol information is for educational purposes only. Dosing must be determined by a licensed physician based on individual health status and goals.
Regulatory
Legal Status in 2026
This compound has completed clinical trials and received formal FDA approval for one or more indications. It can be legally prescribed by licensed physicians, filled at any licensed pharmacy, and may be covered by insurance. Off-label use by physicians is also legal. This is the highest level of regulatory clearance available in the US.
Evidence
Evidence Tier
Evidence from randomized controlled trials (RCTs) or large observational studies in humans. This is the gold standard — effects have been measured in controlled conditions and results are peer-reviewed and reproducible.
Find a Verified Provider
See which Vial-verified providers offer Glycine — with trust scores, legal credentials, and pricing transparency.