Citrulline supplementation increases the body’s arginine levels. Because arginine is the main substrate for the synthesis of nitric oxide, citrulline ingestion can indirectly increase nitric oxide production. In turn, given the role of nitric oxide in vasodilation, mitochondrial respiration, calcium handling, and glucose uptake, greater amounts of nitric oxide can theoretically improve circulatory health and muscle function and reduce fatigue.
How does citrulline work?
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•Last Updated: May 16, 2025
Supplementation with citrulline boosts arginine levels, which enhances nitric oxide production. This increase in nitric oxide can improve circulatory health and muscle function and reduce fatigue due to its role in vasodilation and other physiological processes.