General Dosage
3-5 g daily; 3 g before bed for sleep
Maximum dose: 10 g/day has been used safely; glycine has a very high safety margin
Glycine Dosage Guide
Evidence:Moderate
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Dosage Recommendations
General recommendation: 3-5 g daily; 3 g before bed for sleep
Timing: Before bed for sleep; any time for collagen/glutathione support
Dosage by Condition
Sleep improvement
3 g 30-60 min before bedModerate
Collagen support
5-10 g dailyEmerging
Glutathione support (with NAC)
3-5 g daily with NAC 600 mgModerate
| Condition | Recommended Dose | Evidence |
|---|---|---|
| Sleep improvement | 3 g 30-60 min before bed | Moderate |
| Collagen support | 5-10 g daily | Emerging |
| Glutathione support (with NAC) | 3-5 g daily with NAC 600 mg | Moderate |
Upper limit: 10 g/day has been used safely; glycine has a very high safety margin
Timing & Absorption
Before bed for sleep; any time for collagen/glutathione support
Can be taken with or without food.
References
- RCTYamadera W, Inagawa K, Chiba S, et al. (2007). Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms. DOI
- RCTSekhar RV, Patel SG, Guthikonda AP, et al. (2011). Deficient synthesis of glutathione underlies oxidative stress in aging and can be corrected by dietary cysteine and glycine supplementation. American Journal of Clinical Nutrition. DOI PubMed
- Błaszczuk A, Barańska A, Kanadys W, Malm M, et al. (2022). Role of Phytoestrogen-Rich Bioactive Substances (Linum usitatissimum L., Glycine max L., Trifolium pratense L.) in Cardiovascular Disease Prevention in Postmenopausal Women: A Systematic Review and Meta-Analysis.. Nutrients. DOI PubMed
- Meta-analysisWittemans LBL, Lotta LA, Oliver-Williams C, Stewart ID, et al. (2019). Assessing the causal association of glycine with risk of cardio-metabolic diseases.. Nature communications. DOI PubMed
- Jia Q, Han Y, Huang P, Woodward NC, et al. (2019). Genetic Determinants of Circulating Glycine Levels and Risk of Coronary Artery Disease.. Journal of the American Heart Association. DOI PubMed
- Van K, McHale LK (2017). Meta-Analyses of QTLs Associated with Protein and Oil Contents and Compositions in Soybean [Glycine max (L.) Merr.] Seed.. International journal of molecular sciences. DOI PubMed
- Siegert W, Ahmadi H, Rodehutscord M (2015). Meta-analysis of the influence of dietary glycine and serine, with consideration of methionine and cysteine, on growth and feed conversion of broilers.. Poultry science. DOI PubMed
Show 4 more references
- Dorne JL, Walton K, Renwick AG (2004). Human variability for metabolic pathways with limited data (CYP2A6, CYP2C9, CYP2E1, ADH, esterases, glycine and sulphate conjugation).. Food and chemical toxicology : an international journal published for the British Industrial Biological Research Association. DOI PubMed
- (1991). Impact of glycine-containing ORS solutions on stool output and duration of diarrhoea: a meta-analysis of seven clinical trials. The International Study Group on Improved ORS.. Bulletin of the World Health Organization. PubMed
- Guasp M, Saiz A, Ruiz-Vives M, Almendrote M, et al. (2025). Progressive Encephalomyelitis With Rigidity and Myoclonus With Glycine Receptor Antibodies: Clinical Features and Outcomes.. Neurology(R) neuroimmunology & neuroinflammation. DOI PubMed
- ReviewSoh J, Raventhiran S, Lee JH, Lim ZX, et al. (2024). The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review.. GeroScience. DOI PubMed