Substrate ·evidence-based
interventions / Glycine / sleep

Does Glycine help sleep? (Grade C evidence)

For sleep, Glycine sits at Grade C — a hint of benefit in limited trials, especially in adults, low certainty, at doses 3 g before bed.

Exact question reviewed

Population
adults
Intervention
Glycine · 3 g before bed
Comparator
not reported
Outcome
sleep
Time horizon
not reported

Bottom line. For sleep, Glycine sits at Grade C — a hint of benefit in limited trials, especially in adults, low certainty, at doses 3 g before bed. [1 RCT]

Direction
benefit
Magnitude
small trials suggest improved subjective sleep quality and reduced next-day fatigue
Grade
C
Certainty
low
Clinical meaning
small but potentially useful
Who it applies to
adults
Dose / form studied
3 g before bed
Safety
not assessed
The one limitation
Claim-specific limitation details are not available in this public record.

Reviewed · Evidence last changed · Claim clm_ec_gly_sleep v0

Grade
C
what does the grade mean?
Certainty
low
what does certainty mean?

Grade C / low: hints of benefit in small trials; a well-run RCT could easily push this to B or to null.

Who it works for

Best-studied in adults. Recorded studied dose: 3 g before bed.

Evidence

StudyDesignRoleCite
New therapeutic strategy for amino acid medicine: glycine improves the quality of sleeppeer-reviewednot classifiedPMID:22293292

Why this grade

Reasoning trace

The current record stores Grade C at low certainty and links 1 publishable source. A claim-specific domain-by-domain grading rationale is not available in this public record, so no reason for upgrading or downgrading is inferred here.

Audit and version

Claim ID
ec_gly_sleep
Claim version
not reported
Governance
legacy, not verified
Last evidence search
not reported
Last editorial review
2026-07-16T05:20:13.789Z

Public receipt · Machine-readable claim · Methodology

Dose & form

Studied intake: 3 g before bed.

How it stacks up for sleep

Grade history

Re-review cadence: every 6 months (Grade C+) · next scheduled by · methodology v1.

Frequently asked

How long does Glycine take to work for sleep?

Trials of Glycine for sleep typically report effects within 2–4 weeks, though individual response varies. Studies rarely find benefit inside 1 week for chronic outcomes.

What dose was used in studies of Glycine for sleep?

Studied doses for Glycine in sleep trials cluster around 3 g before bed. See the dose block for the specific range and how it varies by form.

Does Glycine work for sleep if I'm not deficient?

The effect concentrates in adults. If your baseline is normal, expect a smaller effect than the trial averages.

Glycine or the next-best alternative for sleep?

See the compare block above for the head-to-head with the most-cited alternative. Grade + certainty differences matter more than any single trial.

Related

What this is — and is not

Evidence description
small trials suggest improved subjective sleep quality and reduced next-day fatigue
Substrate's interpretation
The current reviewed record assigns Grade C at low certainty. A domain-by-domain rationale is shown only when recorded.
Discuss with a clinician
If you're on medication or have a condition that changes the calculus, bring the interaction & population blocks above to your pharmacist or prescriber before deciding.
Individualized medical advice
Not provided here or on any Substrate surface (API, agent tool, embed) — see YMYL policy.

Cite this page

Citation is encouraged. The proposed reuse license is CC-BY-4.0; status: pending-governance-ratification.

Plain-text citation
Substrate. Does Glycine help sleep? (Grade C). https://evidencebased.info/interventions/glycine/sleep. Updated 2026-07-16.
BibTeX
@misc{substrate_ventionsglycinesleep,
  author = {Substrate editorial},
  title  = {Does Glycine help sleep?},
  year   = {2026},
  url    = {https://evidencebased.info/interventions/glycine/sleep},
  note   = {Grade C, evidencebased.info}
}

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