Can You Take Caffeine and L-Arginine Together?

Dose or timing may matter

The short answer

Caffeine raises blood pressure through sympathetic activation while L-Arginine lowers it via nitric oxide-mediated vasodilation. Concurrent use may result in opposing cardiovascular effects.

How to arrange timing

Research suggests separating intake by 2-3 hours for optimal benefit from each supplement.

Reference

Reference noted for this combination: Bode-Böger SM et al. L-arginine-induced vasodilation in healthy humans. Biochem Biophys Res Commun. 1998;244(1):234-238

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.