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interventions / Melatonin / blood sugar

Does Melatonin help blood sugar? (Grade C evidence)

Explore current source-reported research for this exact question. These records are separate from the synthesis below; they do not update its grade or establish a recommendation.

Melatonin may modestly help blood sugar in specific populations (Grade C, low certainty), especially in adults. Dose range: varies across trials.

Exact question reviewed

Population
adults
Intervention
Melatonin · varies across trials
Comparator
not reported
Outcome
blood sugar
Time horizon
not reported

Bottom line. Melatonin may modestly help blood sugar in specific populations (Grade C, low certainty), especially in adults. Dose range: varies across trials. [1 SR/meta]

Direction
benefit
Magnitude
Meta-analysis of 12 RCTs: melatonin supplementation significantly reduced fasting glucose and improved insulin sensitivity (QUICKI index), but had no significant effect on insulin levels, HOMA-IR, or HbA1c. A partial biomarker signal on fasting glucose specifically, not comprehensive glycemic control.
Grade
C
Certainty
low
Clinical meaning
small but potentially useful
Who it applies to
adults
Dose / form studied
varies across trials
Safety
uncertain_with_ssri
The one limitation
Claim-specific limitation details are not available in this public record.

Reviewed not reported · Evidence last changed · Open evidence record (version 0)

⚠ Safety in context

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: varies across trials.

Evidence

StudyDesignRoleCite
The Effects of Melatonin Supplementation on Glycemic Control: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.peer-reviewedsupportsPMID:30396207

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_b10-mel-blood-sugar
Claim version
not reported
Governance
legacy, not verified
Clinician review
Not yet reviewed by a licensed clinician
Last evidence search
not reported
Last editorial review
not verified

Public receipt · Machine-readable claim · Methodology

Dose & form

Studied intake: varies across trials.

How it stacks up for blood sugar

Grade history

No grade changes yet. Initial grade assigned; re-reviewed on every 6 months (Grade C+). Methodology v1.

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

Frequently asked

How long does Melatonin take to work for blood sugar?

This record does not report a studied onset time for Melatonin and blood sugar. Do not assume a typical timeframe.

What dose was used in studies of Melatonin for blood sugar?

The recorded studied dose for Melatonin and blood sugar is varies across trials. This is a source detail, not a dose recommendation.

Does Melatonin work for blood sugar if I'm not deficient?

The recorded studied population is adults. This field alone does not show whether deficiency or baseline status changes the effect.

Melatonin or the next-best alternative for blood sugar?

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
Meta-analysis of 12 RCTs: melatonin supplementation significantly reduced fasting glucose and improved insulin sensitivity (QUICKI index), but had no significant effect on insulin levels, HOMA-IR, or HbA1c. A partial biomarker signal on fasting glucose specifically, not comprehensive glycemic control.
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 Melatonin help blood sugar? (Grade C). https://evidencebased.info/interventions/melatonin/blood-sugar. Updated 2026-07-16.
BibTeX
@misc{substrate_smelatoninbloodsugar,
  author = {Substrate editorial},
  title  = {Does Melatonin help blood sugar?},
  year   = {2026},
  url    = {https://evidencebased.info/interventions/melatonin/blood-sugar},
  note   = {Grade C, evidencebased.info}
}

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Current source-reported research

Membership uses admitted intervention and measured-outcome associations for this exact question. Different populations, preparations, comparators and timepoints remain separate. No pooling or update to the synthesis is asserted.