Meta Information
ID:glycine
Name:
Schema Version:2.4_uniform_evidence_2026_06_18
Created
2026-05-21T22:30:00Z
Model
phase-a-upgrade-claude-sonnet-4.6
Interactions
Target id:
/intervention/clozapine
Target name:
Clozapine
Severity:
major
Interaction type:
diminishing
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Glycine may interfere with the mechanism of action of clozapine, an atypical antipsychotic, potentially reducing its therapeutic effectiveness in treating schizophrenia.
Actionable advice:
Glycine should not be taken during clozapine therapy, unless specifically approved by a psychiatrist.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
However, these agents exert little effect alone and may interfere with therapeutic actions of the atypical antipsychotic, clozapine.
Label source:
PubMed: N-methyl-D-aspartate receptor-coupled glycineB receptors in the pathogenesis and treatment of schizophrenia: a critical review. (PMID 12769627)
Action type:
avoid
Target id:
/circadian/sleep
Target name:
Going to Sleep
Severity:
moderate
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
1
Hours after target:
null
Description:
Glycine acts as an inhibitory neurotransmitter in the brain and helps lower core body temperature, both of which facilitate sleep onset and can improve sleep quality.
Actionable advice:
A glycine dose is best taken approximately 30-60 minutes before the intended bedtime for optimal sleep benefits.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
The decline in the core body temperature might be a mechanism underlying glycine's effect on sleep, as the onset of sleep is known to involve a decrease in the core body temperature.
Label source:
PubMed: New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. (PMID 22293292)
Action type:
separate
Target id:
/intervention/nac
Target name:
N-Acetylcysteine (NAC)
Severity:
moderate
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Glycine and cysteine (from NAC) are the two primary rate-limiting amino acids for the synthesis of glutathione, the body's master antioxidant. Co-supplementation (as GlyNAC) effectively restores glutathione levels.
Actionable advice:
Glycine and NAC are best taken at the same time to maximize support for glutathione production.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
In prior studies, we identified that deficiency of the intracellular antioxidant glutathione (GSH) could play a role and reported that supplementing GlyNAC (combination of glycine and N-acetylcysteine [NAC]) in aged mice improved GSH deficiency, OxS, mitochondrial fatty-acid oxidation (MFO), and insulin resistance (IR).
Label source:
PubMed: Supplementing Glycine and N-Acetylcysteine (GlyNAC) in Older Adults Improves Glutathione Deficiency, Oxidative Stress, Mitochondrial Dysfunction, Inflammation, Physical Function, and Aging Hallmarks: A Randomized Clinical Trial. (PMID 35975308)
Action type:
informational_none
Target id:
/class/benzodiazepines
Target name:
Benzodiazepines and other Sedatives
Severity:
moderate
Interaction type:
adverse
Nature:
absolute
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Glycine has a calming, inhibitory effect on the central nervous system, which can be additive with the effects of sedative medications, potentially causing excessive drowsiness or dizziness.
Actionable advice:
This is best used with caution when taking sedative medications, and driving or operating heavy machinery is best avoided until the effect of the combination is known.
Validation status:
validated_via_expert_review
Evidence tier:
tier_c
Evidence basis:
expert_review_verbatim
Evidence anchors:
Exact phrase from label:
Glycine is the main neurotransmitter that mediates the inhibitory actions of spinal cord interneurons.
Label source:
Expert review: Glycine is a major inhibitory neurotransmitter in the spinal cord and brainstem acting on strychnine-sensitive glycine receptors (GlyRs), producing chloride ion influx and neuronal hyperpolarization. Exogenous glycine supplementation adds to CNS inhibitory tone, which is mechanistically additive with GABA-A-potentiating benzodiazepines.
Action type:
informational_none
Target id:
/dietary/meal
Target name:
Any Caloric Meal
Severity:
minor
Interaction type:
diminishing
Nature:
temporal
Temporal spacing:
Hours before target:
null
Hours after target:
2
Description:
When taken with food, particularly protein, glycine must compete with other amino acids for absorption, which can slow its uptake and blunt the acute peak needed for sleep-promoting effects.
Actionable advice:
For best sleep-related results, glycine is best taken on an empty stomach, at least 2 hours after the last meal.
Validation status:
validated_via_pubmed
Evidence tier:
tier_b
Evidence basis:
pubmed_abstract_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
High-protein meals or oral phenylalanine, leucine, or isoleucine (100 mg per kilogram of body weight) reversed the therapeutic effect of infused levodopa without reducing plasma levodopa concentrations. Glycine and lysine at identical doses had no effect.
Label source:
PubMed: The New England journal of medicine (1984)
Source url:
Exact phrase from label:
the uptake of most AAs, except glycine and lysine, was inhibited by L-Met (p < 0.001).
Label source:
PubMed: Nutrients (2024)
Source url:
Exact phrase from label:
A cross-inhibition study of the uptake of these amino acids in the brush border of guinea-pig intestine revealed the presence of at least three Na+-dependent and three Na+-independent carrier-mediated systems. One Na+-dependent system interacted mainly with imino acid. Another Na+-dependent system interacted with neutral amino acids, while a third system was selective for glycine.
Label source:
PubMed: Biochimica et biophysica acta (1989)
Action type:
separate
Target id:
/intervention/collagen-peptides
Target name:
Collagen Peptides
Severity:
minor
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Collagen is naturally rich in glycine. Supplementing with additional glycine alongside collagen provides an abundance of the key building blocks required for the body's synthesis of new collagen.
Actionable advice:
Taking glycine and collagen together is safe and may provide enhanced support for skin, joint, and connective tissue health.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Source url:
Exact phrase from label:
This review highlights matrikines originating from the lung, particularly the collagen-derived tripeptide Pro-Gly-Pro (PGP) and the elastin-derived hexapeptide Val-Gly-Val-Ala-Pro-Gly (VGVAPG), as potential mediators linking pulmonary pathology with neurological outcomes.
Label source:
PubMed: Extracellular Matrix-Derived Matrikines: Circulating Peptides as Candidate Mediators of Lung-to-Brain Signaling. (PMID 41977513)
Action type:
informational_none
Target id:
/dietary/high-carbohydrate-meal
Target name:
High-Carbohydrate Meal
Severity:
minor
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Glycine may improve glucose disposal and insulin sensitivity, potentially helping to moderate the rise in blood sugar after a carbohydrate-containing meal.
Actionable advice:
Consider taking glycine with or just before a meal high in carbohydrates to potentially blunt the post-meal glucose spike.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Exact phrase from label:
glycine supplementation reversed obesity-associated glycine deficiency and enhanced the glycine conjugation detoxification reaction, 1-carbon cycle flux
Label source:
Primary literature: https://pmc.ncbi.nlm.nih.gov/articles/PMC11275102/
Action type:
informational_none
Target id:
/dietary/high-methionine-meal
Target name:
High-Methionine Meal (e.g., Red Meat)
Severity:
minor
Interaction type:
synergistic
Nature:
temporal
Temporal spacing:
Hours before target:
0
Hours after target:
0
Description:
Glycine supplementation can help balance the high methionine intake common in diets rich in muscle meats, which is theorized to support longevity by managing homocysteine pathways.
Actionable advice:
Taking glycine with a high-protein meal, such as red meat, may help balance the overall amino acid profile.
Validation status:
validated_via_primary_literature
Evidence tier:
tier_b
Evidence basis:
primary_literature_verbatim
Evidence anchors:
Exact phrase from label:
Glycine may reduce homocysteine levels following high-protein meals
Label source:
Primary literature: https://www.healthline.com/nutrition/methionine-vs-glycine
Action type:
informational_none