Glycine
Amino Acid
Also known as: Gly
B
Grade B💊 3-5 g before bed for sleep; up to 10-15g for other uses🎯 4 primary uses🔗 3 synergies⚠️ Review warnings
Levels upFitness+50 pts
Overview
Simplest amino acid with diverse roles in collagen synthesis, sleep quality, neurotransmission, and detoxification.
Primary Uses
Sleep qualityCollagen synthesisDetoxificationNeuroprotection
Frequently Asked About Glycine
How much Glycine should I take?
The typical effective range is 3-5 g before bed. Individual needs vary based on age, body weight, diet, and goals — start at the lower end and adjust based on response. Always consult a healthcare provider before starting a new supplement.
When is the best time to take Glycine?
Before bed for sleep. Consistency matters more than perfect timing — pick a daily anchor (e.g. with breakfast or before bed) and stick with it.
Should I take Glycine with food?
Optional.
Does Glycine interact with medications?
Yes — known interactions include Clozapine interaction theoretically. If you take any prescription medication, talk to your doctor or pharmacist before starting Glycine.
What does Glycine pair well with?
Glycine stacks well with Magnesium, NAC, and Vitamin C — these combinations either improve absorption or work synergistically toward common goals.
Who should not take Glycine?
Glycine should be avoided or used with caution by people with None. Pregnant or breastfeeding women should consult a healthcare provider before use.
What are the side effects of Glycine?
Most people tolerate Glycine well. The most commonly reported side effects are Mild sedation and GI upset at high doses. Side effects are usually dose-dependent — lowering the dose often resolves them.
Dosage
Typical range
3-5 g before bed for sleep; up to 10-15g for other uses
Timing
Before bed for sleep
With food
Optional
Dose Tiers
Moderate
3 g before bed
Optimal
3-5 g before bed
Therapeutic
10-30 g/day in divided doses
Upper Limit
No established UL
Duration
Safe long-term
Special Populations
Poor sleepers, detox support
Research & Studies
Landmark clinical studies on Glycine. Each title links to a plain-English breakdown — what the study shows, what its limitations are, and how to read around them.
- The sleep-promoting and hypothermic effects of glycine are mediated by NMDA receptors in the suprachiasmatic nucleus
Mechanistic study identifying how glycine at bedtime lowers core body temperature via NMDA receptor activation in the SCN — the proposed mechanism for its observed sleep-onset latency benefits.
- Glycine ingestion improves subjective sleep quality in human volunteersYamadera W, Inagawa K, Chiba S, et al. · 2007 · Sleep and Biological RhythmsRCT
Crossover RCT showed 3g glycine 30–60 minutes before bed improved subjective sleep quality, sleep-onset latency, and next-day fatigue vs placebo in self-reported mild insomnia subjects.
Browse all curated studies →
Mechanism of Action
- • Inhibitory neurotransmitter
- • Precursor to glutathione
- • 1/3 of collagen amino acids
- • Lowers core body temperature
Evidence Quality
Evidence Grade B
Growing evidence for sleep and health
Safety & Contraindications
Serious Warnings
- • None
Contraindications
- • None
Common Side Effects
- • Mild sedation
- • GI upset at high doses
Pregnancy & Breastfeeding
Consult healthcare provider
Liver & Kidney Notes
May support liver
Interactions
💊 Medications
- • Clozapine interaction theoretically
🧪 Supplements
- • Works with magnesium for sleep
🍽️ Food & Alcohol
- • No interactions
Stacking & Synergies
Pairs Well With
Avoid Combining With
None
Best Goal Synergies
SleepCollagenDetox
Buying Guide
What to Look For
- • Pure glycine
Standardization Markers
Purity
Adulteration risk
Low
Practical Notes
- • 3g before bed improves sleep quality
- • Sweet taste - can add to drinks
Tags
amino acidsleepcollagendetox
Top Products with Glycine
Highest-scored catalog products containing Glycine, ranked by our scoring engine.
Browse all Glycine products →
Related Guides
In-depth guides covering Glycine — protocols, comparisons, and use cases.
More in Amino Acid
Other ingredients in the Amino Acid category.
5-HTP
Direct serotonin precursor, one step closer than tryptophan. More potent for mood and appetite but requires more caution.
Glycine (for Relaxation)
Simplest amino acid with profound calming and sleep effects. Lowers body temperature.
Glycine (Longevity Dose)
Simplest amino acid with emerging longevity benefits at higher doses. Supports glutathione, collagen, sleep, and may mimic methionine restriction.
Hydrolyzed Whey Protein
Pre-digested whey protein with faster absorption than isolate or concentrate, ideal for post-workout recovery and those with digestive sensitivities.
L Carnitine
L-carnitine is a naturally occurring compound synthesized from amino acids that plays a crucial role in transporting long-chain fatty acids into mitochondria for energy production. Evidence supports modest benefits for exercise performance and recovery in carnitine-deficient individuals, though benefits in healthy populations are limited.
L-Arginine
A conditionally essential amino acid that serves as a precursor to nitric oxide, supporting vasodilation and blood flow. Most evidence supports benefits for endothelial function and exercise performance, though clinical results are mixed.
Last reviewed: September 2026 by the Formulate Research Team. Sources cited above; methodology and scoring criteria published here.
Cite this page
Formulate Research Team. (2026, September). Glycine — Evidence-Based Supplement Guide. Formulate Supplement Encyclopedia. https://app.formulate-health.app/learning/supplements/glycine
Educational content based on published research and our scoring methodology. Not medical advice — consult a qualified healthcare provider before starting, stopping, or changing supplements, especially if you take medications, are pregnant, or have a medical condition.