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compare / Melatonin vs L-Theanine

Melatonin vs L-Theanine for sleep: which has better evidence?

Melatonin has the stronger evidence for sleep (Melatonin Grade B vs L-Theanine Grade C). For sleep, Melatonin has the stronger evidence grade.

Reviewed by Substrate editorial, Independent research collective ·

Platform evidence comparison

These existing platform assessments are separate from the source-reported findings below. They do not represent a direct trial comparing these treatments.

MelatoninL-Theanine
Gradegrade Bgrade C
Certaintymoderatelow
Effectreduces time to fall asleep; best for circadian timingmay improve subjective sleep quality via relaxation rather than sedation
Studied dose0.5–3 mg200 mg before bed
Population—adults
Safety1 modeled interaction(s)0 modeled interaction(s)
Grade
B
what does the grade mean?
Certainty
moderate
what does certainty mean?

Grade B / moderate: probably helps, and new studies are unlikely to reverse this — but could shrink the effect size.

Direct comparison evidence

There are no direct RCTs in our corpus comparing Melatonin and L-Theanine head-to-head for sleep. What we present above is an indirect comparison: each side's own trials, contrasted. This is standard practice for supplement comparisons — dose, population, and outcome-instrument differences between the two evidence bases add uncertainty on top of each side's own grade.

Can you take both?

No modeled interaction between Melatonin and L-Theanine in our corpus. Absence of a recorded interaction is not proof of additive benefit — combined-effect trials are usually absent for supplement pairs, so treat "stack" claims skeptically.

This filtered view rechecked source-context candidates for current publication and source integrity. Other papers were not evaluated; an empty result does not establish that research is absent. Browse the broader bounded research library.

Source-reported research findings

AI-extracted — pending human review. These findings retain the studied context and are not pooled treatment estimates.

Single study

PMID 38745424: PSQI

  • AI-extracted — pending human review
  • Extraction status: machine extracted. Source status is not human clinical review.
  • Publication status: published. Record review status: not reviewed.
  • Not poolable: one source-reported result, not a pooled treatment estimate.

Authors reported a direction only for sleep quality (PSQI): favours the studied intervention.

Reported p < 0.05.

  • Studied combination: 1.9 mg melatonin + 200 mg elemental magnesium.
  • Studied route/context: unclear.

otherwise healthy individuals with sleep disturbances; double-blinded, randomized, crossover trial. supplement condition versus placebo. sleep quality (PSQI) at 4 week intervention.

Related research with a different studied context; applicability to this question remains limited.

That’s the gist — a fine place to stop. This describes the studied groups, not personal suitability.

Read this finding in study context →Original source · Bring into My Profile

Decision guidance

sources: PMID:23691095 · PMID:15649737 · PMID:40056718

Grade history

No grade changes yet. Initial grade assigned; re-reviewed on every 12 months (Grade A/B) — next review by . Methodology v1.

Re-review cadence: every 12 months (Grade A/B) · next scheduled by · methodology v1.

Frequently asked

Which has stronger evidence: Melatonin or L-Theanine for sleep?

Melatonin carries Grade B at moderate certainty; L-Theanine carries Grade C at low. The stronger evidence points to Melatonin, subject to the caveat that direct head-to-head trials are usually absent for supplement pairings.

Can I take Melatonin and L-Theanine together?

No modeled interaction between Melatonin and L-Theanine; combining is not documented to be problematic, but combined-effect trials are also absent, so treat additive benefit claims skeptically.

Have Melatonin and L-Theanine been compared head-to-head?

Direct RCTs comparing the two for sleep are uncommon. This page contrasts each side's own trial evidence — that is an indirect comparison, which introduces confounds from population and dose differences. See the direct-comparison block above.

What decides between Melatonin and L-Theanine for me?

Read the decision guidance below — the split usually comes down to population fit, interaction risk with your other medications, and how much certainty you want behind the recommendation.

Related

Cite this page

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

Plain-text citation
Substrate. Melatonin vs L-Theanine for sleep. https://evidencebased.info/compare/melatonin-vs-theanine-for-sleep. Updated 2026-07-14.
BibTeX
@misc{substrate_invstheanineforsleep,
  author = {Substrate editorial},
  title  = {Melatonin vs L-Theanine for sleep},
  year   = {2026},
  url    = {https://evidencebased.info/compare/melatonin-vs-theanine-for-sleep},
  note   = {evidencebased.info}
}