Glycine

glycine

A simple amino acid studied for sleep quality and, with NAC, for aging biomarkers.

TipoSupplement / dietary

Il voto risponde a: What does the human evidence support for: Sleep, methylation & metabolic support?

Grado

Limitata

Il voto misura la qualità dell'evidenza, non è un consiglio ad assumere o acquistare.

Classe: Amino acid
Uso principale: Sleep, methylation & metabolic support
Forza evidenza: low
Ultima revisione: 2026-07-01

In sintesi

Cheap, safe, with a modest evidence base for sleep quality and a role in the experimental GlyNAC combination. As a stand-alone longevity molecule the human data are thin.

Cosa dice l'evidenza

Glycine is a non-essential amino acid with a few small trials suggesting improved subjective sleep quality and next-day alertness when taken before bed, plus a supporting role in the GlyNAC (glycine + N-acetylcysteine) work aimed at restoring glutathione and mitochondrial markers in older adults. On its own the longevity evidence is early and mechanistic rather than outcome-based. Grade C: safe and mildly useful for sleep, unproven as an aging intervention.

Studi chiave

[1]
Glycine before sleep and sleep quality · RCT
Small improvements in subjective sleep and next-day alertness.
Apri su PubMed ↗
[2]
GlyNAC (glycine + NAC) and aging markers in older adults · pilot trial
Improved glutathione and mitochondrial markers in small trials.
Apri su PubMed ↗
[3]
Glycine metabolism and physiology (review) · review
Background on its many metabolic roles.
Apri su PubMed ↗

Vedi tutti gli studi su PubMed ↗

Meccanismo

Acts as an inhibitory neurotransmitter and glutathione precursor, contributes to collagen and creatine synthesis, and may lower core body temperature to aid sleep onset.

Sicurezza

Very well tolerated as a dietary amino acid; high doses may cause mild GI upset. No significant safety concerns at studied intakes.

Contesto dosaggio

Sleep studies commonly use ~3 g before bed; GlyNAC protocols use higher, weight-based doses under study conditions. No validated longevity dose exists for glycine alone.

Esempi di applicazione

Taken ~3 g before bed for sleep quality.
Also the glycine half of the experimental GlyNAC combination.
Cheap and gentle, not a transformative aging intervention.

Nota dal campo

Glycine is the quiet ingredient behind the GlyNAC headlines. On its own it's a reasonable, cheap sleep aid — not the aging reversal the combination studies get spun into.

Molecole correlate

GlyNAC (glycine + NAC)C

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