Glycine

Research records

Historical source snapshot. Not freshly verified, not a recommendation. Study findings, community accounts and app defaults are not interchangeable.

Publication suitability · 2026-10-15: Historical reference only; not a clinical verification. Clinical, regulatory, efficacy, safety and dose claims are not independently established by this review.

Glycine

Amino acid studied for sleep quality and as a glutathione precursor.

Evidence category: Clinical study. This describes the source category, not approval or certainty.

Regulatory statement in source: Not separately recorded; do not infer approval from the evidence category.

Glycine is an amino acid studied for sleep. Small human trials from one research group report better subjective sleep quality in people who sleep poorly, and less fatigue with better psychomotor vigilance after nights of restricted sleep. Rat experiments point to a fall in core body temperature through NMDA receptors in the suprachiasmatic nucleus as the mechanism. The human evidence is limited to a few small studies; nothing here covers athletic use.

Benefits reported in the imported source

• Small human trials report better subjective sleep quality in people who sleep poorly
• After restricted sleep, fatigue fell and psychomotor vigilance improved

Risks and limits

• The human evidence is a few small studies from one research group
• Melatonin and clock-gene expression were unchanged, and sleepiness only tended to fall
• The cooling mechanism comes from rat work; nothing here covers athletic use

Source bottom line: Glycine improved reported sleep and next-day alertness in a few small trials from one group.

Uncertainty: Reference information only. Not medical advice.

Study protocols — reports, not instructions

Community and practice descriptions

Accounts of a practice are not evidence of safety or effectiveness. Words such as “standard”, “safe” or “recommended” describe the source account, not verified consensus or this wiki’s advice. Commercial and self-published citations are retained for traceability, not vendor endorsement or independent clinical corroboration.

Pharmacokinetic context

No half-life recorded in this source snapshot. No value has been inferred.

Source references

• New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep (Bannai 2012)
• The sleep-promoting and hypothermic effects of glycine are mediated by NMDA receptors in the suprachiasmatic nucleus (Kawai et al. 2015)
• The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers (Bannai et al. 2012)
• PubMed: glycine sleep (availability check 2026-10-15: possible access barrier; not independently inspected; HTTP 200)