Evidence overview
Glycine
Glycine is the simplest amino acid and a multi-role compound studied as a sleep aid, schizophrenia adjunct therapy (via NMDA receptor modulation), surgical recovery and wound healing support, and connective tissue cofactor. The research base is moderate in size and spans an unusually wide range of mechanisms, which makes individual outcome research less unified than for many supplements.
Most studied for
Coverage pending
PubMed coverage
Coverage pending
Safety profile
In your full report
Mechanism class
Simplest amino acid; serves multiple distinct physiological roles - inhibitory neurotransmitter in the spinal...
Study coverage
Study coverage by goal
PubMed counts for Glycine grouped by the goal each study targets.
Evidence overview is temporarily unavailable for Glycine.
Evidence
What the evidence covers
The terrain of the published literature, not its conclusions.
Glycine is the simplest amino acid and is studied across an unusually wide range of indications because it serves multiple distinct physiological roles: inhibitory neurotransmitter in the spinal cord and brainstem, co-agonist at brain NMDA glutamate receptors, building block for collagen and creatine, and a one-carbon-metabolism donor. The supplement literature covers sleep quality, schizophrenia treatment (as an NMDA receptor modulator), surgical recovery and wound healing, glucose tolerance and insulin sensitivity, and skin and connective tissue applications. The supplement is sold as the bare amino acid or in combination products targeting specific use cases.
The outcome dimensions covered most heavily are sleep quality (particularly subjective sleep onset and morning alertness, studied at doses around 3 grams before bedtime), schizophrenia and psychotic symptoms as an adjunct to antipsychotics (where glycine is part of the broader NMDA-receptor-modulator literature), surgical recovery and post-operative metabolism, insulin sensitivity and glucose tolerance, and oxidative stress markers. Smaller research streams cover skin and joint health (where glycine is a major structural component of collagen) and ischemic injury models in preclinical research.
Demographically, the schizophrenia literature concentrates on adults on stable antipsychotic regimens; the sleep literature is mostly in healthy adults with self-reported sleep difficulties; the surgical-recovery literature is in adults undergoing planned procedures. The unusually broad mechanism set makes glycine difficult to characterize as a single-purpose supplement, which is one of the field's recurring methodological challenges - the same dose may produce changes across multiple systems that are studied separately and rarely measured together.
Safety
Safety summary
Common adverse events, drug interactions, and special populations.
Glycine is generally well-tolerated at supplemental doses. The most-common adverse effects at higher doses (above ~10 g/day) are mild gastrointestinal discomfort, nausea, and stomach upset. No tolerable upper limit has been established. Drug interactions are limited; a specific interaction has been reported with clozapine (an antipsychotic) where glycine may reduce its efficacy in some clinical reports, and theoretical interactions exist with other NMDA-active medications. Glycine has been used safely at very high pharmacological doses (15-60 g/day) in some psychiatric trials, but those are clinical research contexts rather than consumer supplementation. People on clozapine specifically should not supplement without medical supervision.
This summary is informational and not medical advice. Consult a clinician before starting or changing any supplement, especially if you take prescription medications.
Foundations
Foundation of the evidence base
A few studies the field anchors on. Not the full picture, just the starting points.
Recent supplement-level systematic review covering glycine across multiple physiological systems in human adults - the closest the field has to a unifying reference document for glycine, whose multi-role mechanism makes single-purpose framing difficult.
View on PubMedMeta-analysis of NMDA receptor modulator augmentation in schizophrenia, of which glycine is a principal compound. Establishes the field's pooled-evidence reference for glycine's most-cited clinical use; the scope also includes related modulators (D-serine, sarcosine), which is the trade-off accepted for the breadth of the synthesis.
View on PubMed
Limitations
What this page doesn't answer
Where the public summary stops and the personalized report begins.
This page summarizes the glycine literature at a general level. It does not address which use case is most relevant for your goal (sleep, mood, recovery, skin/joint), what dose is appropriate (typical sleep research uses ~3 g while schizophrenia research uses much higher doses), how glycine interacts with your specific medications (especially clozapine), or whether your dietary protein intake already provides adequate glycine for collagen-related uses. The multi-mechanism nature of glycine means goal selection matters more than for many supplements, which is exactly the kind of question the personalized report can address.
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