GABA (Gamma-Aminobutyric Acid)

Last reviewed: 4/3/2026

Absorption

✦Take on an empty stomach 30-60 minutes before bedtime for sleep support. Peak blood levels occur approximately 30 minutes after oral administration. Avoid combining with sedative medications or alcohol.

Daily Dose

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Common dose: 100-200 mg/day

RDA: No established RDA

Upper limit: No established upper limit; up to 300 mg/day used in studies

Best form: Biosynthetic GABA (PharmaGABA) or fermented GABA

Timing: 30-60 minutes before bedtime

A 2020 systematic review concluded evidence for stress benefits is limited and for sleep is very limited.

Effects

Food Sources

Fermented foods (kimchi, tempeh)Varies widely
Tomatoes~62 mg per 100g
Green tea~0.2-0.5 mg per cup