How strong is the evidence for GABA?

The overall grade on file is C (limited). 2 claimed benefits are graded separately in the table above. The entry cites 1 study.

What dose of GABA has been studied?

The range on file is 100-750 mg (1-2 doses). It describes doses used in research, not a recommendation.

What are the side effects of GABA?

Recorded side effects: Tingling / paresthesia (common), Headache (uncommon). Safety score 4/5.

GABA

GABA (gamma-aminobutyric acid) is the main inhibitory neurotransmitter of the brain. Oral GABA has limited evidence for subjective relaxation, and whether it reaches the brain is debated.

Evidence: CLimited evidence
Studied dose: 100-750mg
Safety score
Verified references: 1 study

How entries are graded Report an error in this entry Corrections policy

How it is thought to work

GABA acts at GABA-A and GABA-B receptors. Oral GABA is thought to cross the blood-brain barrier poorly; any calming effect may be mediated by enteric receptors and vagal signaling, with limited supporting evidence.

Where to buy GABA

Affiliate links

Ad Affiliate links, we may earn a commission at no extra cost to you. As an Amazon Associate we earn from qualifying purchases.

Vendor	Product	Size	Price	Per unit	Buy
Amazon	NOW Supplements, GABA 750mg, Cognitive Support*, 100 Veg...	-	On Amazon	-	Check price on Amazon Ad
iHerb	NOW Foods, GABA , 100 Veg Capsules	-	about $9.17 at iHerb (as of 24 September 2026)	-	Shop Ad
iHerb	Nature's Way, GABA, 250 mg, 60 Vegan Capsules	-	about $12.56 at iHerb (as of 24 September 2026)	-	Shop Ad
iHerb	Nutricost, GABA, 750 mg, 240 Capsules	-	about $19.95 at iHerb (as of 24 September 2026)	-	Shop Ad

What the studies found

2 benefits are graded: 2 limited (C).

Claimed benefit	Grade	Basis
Subjective relaxation / stress reduction	C	Abdou 2006.[1]
Gut-brain calming via vagal afferents	C	BBB penetration is poor; the calming effect appears mediated by enteric receptor binding and vagal signaling.

Each benefit is graded on its own; a substance can have strong evidence for one effect and little for another. What the grades mean.

Dose and timing

Studied dose range

Doses used in the research on file, taken as 1-2 doses. Not a recommendation.

GABA dosage record in full

Safety and interactions

Recorded side effect	How often	Severity
Tingling / paresthesia	common	mild
Headache	uncommon	mild

Side effects in detail Interaction checker

History

GABA was identified in plants in 1883, and Eugene Roberts recognised it as a brain neurotransmitter in 1950. Abdou 2006[1] reported subjective relaxation and increased EEG alpha waves at 100 mg.

References

Relaxation and immunity enhancement effects of GABA administration (Abdou). 2006. PubMed 16971751

Reader reviews

0 published

No reader reviews have been published for this substance yet.

Share your experience

Reviews require disclosed dose, duration, and conflict of interest. Posted after editorial review.

GABA: quick answers

How strong is the evidence for GABA?: The overall grade on file is C (limited). 2 claimed benefits are graded separately in the table above. The entry cites 1 study.
What dose of GABA has been studied?: The range on file is 100-750 mg (1-2 doses). It describes doses used in research, not a recommendation.
What are the side effects of GABA?: Recorded side effects: Tingling / paresthesia (common), Headache (uncommon). Safety score 4/5.

Compared with other substances

Show 2

Comparison	Grade	Class
GABA vs Creatine	A	Amino acid
GABA vs L-Theanine	A	Amino acid

Our annual report

The State of Nootropics 2026

Nootropics.com's own editorial reference, published as a 358-page paperback and as PDF and Kindle editions. The full edition is paid, and we earn from sales. An eight-chapter edition is free by email. Like this page, it is a research summary, not medical advice.

About the report and its editions