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Head-to-head evidence comparison — which supplement is right for you?
Melatonin wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
3 of 3 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
19 of 24 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (2)
Outcomes where both GABA and Melatonin have evidence — compare verdict strength side-by-side.
250-750mg
30-60 minutes before desired effect, Before bed for sleep, Before stressful events for anxiety
Capsules or powder
0.5-1mg
30-60 minutes before bed
Immediate-release tablet or sublingual
30-60 minutes
30-60 minutes
30-60 minutes
Same night
1-3 days
Next morning
First week
Herbal Remedies and Their Possible Effect on the GABAergic System and Sleep
Nutrients (2021) · Systematic review
Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that plays a major role in controlling different vigilance states.
Effect of Probiotics on the Symptomatology of Autism Spectrum Disorder and/or Attention Deficit/Hyperactivity Disorder in Children and Adolescents: Pilot Study
Research on child and adolescent psychopathology (2025) · Rct · n=80
A better comfort score (quality of life) was shown in children with ASD (probiotic: p = 0.010, Cohen's d = 0.722; placebo: p = 0.099, Cohen's d = 0.456).
GABA Supplementation, Increased Heart-Rate Variability, Emotional Response, Sleep Efficiency and Reduced Depression in Sedentary Overweight Women Undergoing Physical Exercise: Placebo-Controlled, Randomized Clinical Trial
Journal of dietary supplements (2024) · Rct · n=90
Moreover, an improved emotional response was observed, characterized by diminished negative affect.
Melatonin in cancer treatment
The Cochrane database of systematic reviews (2025) · Meta analysis · n=126
We downgraded the certainty of the evidence because of high risk of bias, small sample size, the width of the 95% confidence interval, and indirectness due to inadequate reporting of cancer type.
Comparative Efficacy, Tolerability, and Acceptability of Donanemab, Lecanemab, Aducanumab, Melatonin, and Aerobic Exercise for a Short Time on Cognitive Function in Mild Cognitive Impairment and Mild Alzheimer's Disease: A Systematic Review and Network Meta-Analysis
Journal of Alzheimer's disease : JAD (2024) · Meta analysis · n=4599
Melatonin may be a better potential disease-modifying treatment for cognitive decline in mild AD and MCI.
Melatonin for sleep disorders in people with autism: Systematic review and meta-analysis
Progress in neuro-psychopharmacology & biological psychiatry (2023) · Meta analysis · n=595
According to the global analysis, the wake after sleep onset and night awakening parameters were not statistically significant.
Limited direct GABA supplementation studies. Most evidence comes from GABA receptor agonist research showing somnolence as primary effect (RR 4.56). Effectiveness estimates are conservative given sparse direct supplementation data and questionable oral bioavailability of GABA across blood-brain barrier.
Based on meta-analyses showing 7-12 minute reduction in sleep onset. Higher doses showed diminishing returns and increased morning grogginess. Sublingual forms may be more effective at lower doses.
AI-estimated from published studies. Interpret as directional guidance.
Melatonin has a higher evidence score (8.5/10 vs 4/10) and wins in 2 of 3 categories.
For fix sleep schedule / jet lag, Melatonin has a higher relevance score (98 vs 60).
No known interactions between GABA and Melatonin have been documented in our database. However, always consult a healthcare provider before combining supplements.