Can You Take GABA and Suntheanine (L-Theanine) Together?

Use extra care with this pair

The short answer

Suntheanine (L-Theanine) increases GABA levels in the brain. Combining with supplemental GABA may cause additive inhibitory neurotransmission, leading to excessive sedation and drowsiness.

How to arrange timing

Use lower doses of each when combining Suntheanine and GABA. Monitor for excessive drowsiness.

Reference

Reference noted for this combination: Kimura K, et al. L-Theanine reduces psychological and physiological stress responses. Biol Psychol. 2007;74(1):39-45.

Important context

Whether supplements suit you together also depends on dose, product formulation, health conditions, and medication use. Ask a doctor or pharmacist first if you take medication, are pregnant or breastfeeding, or have a chronic condition.