L-Citrulline + L-Arginine

Two amino acids that feed the same nitric oxide synthesis pathway from different angles — L-citrulline is converted to L-arginine in the kidneys, and L-arginine is the direct substrate for endothelial nitric oxide synthase (eNOS).

Stacking them helps maintain elevated plasma arginine for a longer window than either alone — L-citrulline absorbs slowly and steadily, while L-arginine spikes faster. The combination supports vasodilation, nutrient delivery to working muscle, and the muscle pump that strength athletes train for.