Interaction checker

Can you take Theanine with Caffeine?

L-Theanine + Caffeine

Camfield et al. (2014, Nutr Rev meta-analysis) and Kahathuduwa et al. (2025) show small-to-moderate effects on attention switching and alertness within 1–2 hours of co-administration. Theanine modulates caffeine's jittery edge while preserving focus benefits — effect is largely caffeine-driven; theanine adds smoothness. Typical pairing: 100 mg L-theanine + 50–100 mg caffeine.

Supplement-to-supplement only. For interactions with prescription medications, talk to your doctor or pharmacist.

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L-Theanine + Caffeine

Camfield et al. (2014, Nutr Rev meta-analysis) and Kahathuduwa et al. (2025) show small-to-moderate effects on attention switching and alertness within 1–2 hours of co-administration. Theanine modulates caffeine's jittery edge while preserving focus benefits — effect is largely caffeine-driven; theanine adds smoothness. Typical pairing: 100 mg L-theanine + 50–100 mg caffeine.

Do Theanine and Caffeine actually work at your doses?

BioStacks scores supplements on clinical efficacy — real doses vs. the research. Scan a bottle and see.