Small stress and sleep studies used 100–300 mg/day for 1–8 weeks in adults
Reviewed · Published
GABA
An inhibitory neurotransmitter, though brain entry and clinical effects of oral GABA are uncertain.
Established functions
- An inhibitory neurotransmitter, though brain entry and clinical effects of oral GABA are uncertain.
Dietary sources
- germinated brown rice
- tomatoes
- fermented foods
Claims and evidence
Claims that GABA alone prevents or treats disease, or invariably improves health without deficiency, are unsupported.
Japanese reference amounts
- Japanese adults (age and sex as specified): No Japanese DRI established
Amounts studied
- Small stress and sleep studies used 100–300 mg/day for 1–8 weeks in adults
Tolerable upper limits
- No UL; long-term safety is unknown
Forms and bioavailability
Supplement forms: fermented GABA, synthetic GABA
- The GABA molecule is the same from fermentation, but accompanying compounds differ.
Safety and interactions
Adverse effects
- drowsiness
- abdominal discomfort
- transient breathing sensations
Medicine and nutrient interactions
- antihypertensives, sedatives
Contraindications and cautions
- Avoid or consult during pregnancy, lactation, hypotension, or sedative use.
Practical selection
- Compare GABA amount per serving, form, allergens, and batch testing; prefer a single-ingredient product suited to the intended use.
Sources and review
- NCCIH Herbs at a Glance and supplement safety resourcesNational Center for Complementary and Integrative Health
Daiki Minaki (editorial and evidence review) ·
Frequently asked questions
How is GABA different from its broader supplement category?
An inhibitory neurotransmitter, though brain entry and clinical effects of oral GABA are uncertain. Compare its named form and amount rather than assuming every category product supplies it.
View detailsWhat safety detail matters specifically for GABA?
antihypertensives, sedatives Avoid or consult during pregnancy, lactation, hypotension, or sedative use.
View details