GABA (Gamma-Aminobutyric Acid)
Also known as: gamma-aminobutyric acid, PharmaGABA, γ-aminobutyric acid
The brain's main inhibitory neurotransmitter, sold as a supplement for relaxation and sleep. Whether oral GABA crosses the blood-brain barrier is debated; the effects reported in small trials at around 100–300 mg may act through the enteric nervous system or vagal signaling. A systematic review judged the evidence for stress reduction limited but promising, and weaker for sleep. It is popular in calming gummies and drinks.
Research summary
Activates GABA-A and GABA-B receptors; oral doses may act peripherally via the gut-brain axis rather than by direct central uptake.
Dosage
Daily amounts, of compound.
| Lowest studied | Typical range | Highest studied | Upper limit |
|---|---|---|---|
| 100 mg | 100–500 mg | — | — |
Stress studies typically used 100 mg as a single dose and sleep studies around 300 mg before bed; products range from 100–750 mg. Effects in the trials appeared within about an hour. Fermentation-derived (natural) GABA is often specified over synthetic for marketing reasons, with no established efficacy difference.
Source material: fermentation-derived (Lactobacillus hilgardii) or synthetic
Format suitability
- Capsule
- Powder
- Tablet
- Softgel
- Gummy
- Liquid
Highly soluble with a neutral taste; suits gummies and beverages.
Formulation notes
Paired with theanine, magnesium, and glycine in calming formulas. Additive sedation with alcohol or sedative drugs is a label consideration.
Sources
Related ingredients
Ashwagandha Root Extract (KSM-66)
BotanicalA branded, root-only ashwagandha extract standardized to at least 5% withanolides.
Typical: 300–600 mg
Ashwagandha Root Extract (≥5% Withanolides)
BotanicalA generic, non-branded ashwagandha root extract standardized to at least 5% withanolides.
Typical: 300–600 mg
L-Theanine
Amino acidAn amino acid found naturally in green tea that promotes a calm, focused state without sedation.
Typical: 100–200 mg
5-HTP (5-Hydroxytryptophan)
Amino acidThe immediate precursor to serotonin, extracted commercially from Griffonia simplicifolia seeds.
Typical: 50–300 mg
Chamomile Flower Extract
BotanicalAn extract of German chamomile flowers standardized to apigenin, the flavone behind much of its calming reputation.
Typical: 220–1,100 mg