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Amino acid derivative

GABA

GABA (gamma-aminobutyric acid) is an amino acid the body makes from glutamate. It is the main inhibitory, or calming, messenger in the brain.

Also listed as Gamma-Aminobutyric Acid

SleepStress & MoodCognition

What it is studied for

The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.

Sleep OnsetSleepSmallBNo linked study
AnxietyStress & MoodSmallCNo linked study
Sleep qualitySleepSmallCNo linked study
StressStress & MoodSmallCNo linked study
Mood SupportStress & MoodSmallCNo linked study
Chronic StressStress & MoodSmallCNo linked study
All 8 rated effectsGrouped by health goal, with the publications behind each rating

Brain GABA and oral GABA

GABA is an inhibitory neurotransmitter, a chemical messenger that reduces nerve-cell activity. Whether oral GABA reaches the brain in meaningful amounts remains uncertain; its established role in the nervous system does not by itself prove that a supplement improves sleep. 1

Why people take it

Stress & Mood23.5%
Cognition18.6%
Sleep18.1%
Essential Health14.6%
Energy8.2%
Fitness4.5%

SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.

Questions people ask

Is 300 mg a recommended sleep dose?

It was the dose in one short trial, not an established recommendation for insomnia treatment. 2

Can GABA interact with blood-pressure medicine?

An additive blood-pressure-lowering effect is a concern raised by the safety review, rather than a proven interaction in a dedicated trial. 3

Is long-term use known to be harmless?

No. The 2025 diabetes trial recorded liver-enzyme elevations during six months of treatment. 4

Sources

Further reading

Illustration for GABA.GuideGABA for better sleepGABA as a sleep supplement: what studies show, why the blood-brain barrier matters and which uncertainties remain.Read the article Illustration for GABA.GuideGABA breakdown in the gut: what a microbiome test showsA GABA breakdown test estimates the metabolic potential of gut microbes. What it captures, how to interpret the result and where its limits lie.Read the article Illustration for GABA.GuideMicrobial GABA capacity and the gut-brain connectionMicrobiome tests can capture the potential to build and break down GABA. What these functional clues say about the gut-brain connection, and what remains open.Read the article