Does Caffeine Affect L-Theanine?

May affect absorption or how you feel

The short answer

L-theanine modulates caffeine's stimulatory effects, promoting calm focus. Co-administration is generally synergistic but high caffeine may overpower theanine's calming effect.

How to arrange timing

Generally safe together. Reduce caffeine if experiencing jitteriness despite theanine.

Reference

Reference noted for this food and supplement combination: Examine.com 2024; Giesbrecht et al. 2010

Important context

The effect can also change with food amount, supplement 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.