Synopsis

Source of validity: Scientific
Rating (out of 5): 3

L-citrulline is used as an athletic and exercise aid primarily due to its role as a precursor to L-arginine, which in turn is a substrate for nitric oxide (NO) synthesis. Nitric oxide is a vasodilator, meaning it helps relax blood vessels, potentially improving blood flow, oxygen, and nutrient delivery to muscles during exercise. Several peer-reviewed studies suggest that L-citrulline supplementation can increase plasma arginine levels more effectively than arginine supplementation itself, due to better absorption and metabolism. Research indicates that doses of 6–8 grams of L-citrulline or its malate salt (citrulline malate) taken before exercise may reduce perceived exertion, decrease muscle soreness, and improve high-intensity exercise performance, particularly in activities involving repeated bouts (e.g., weightlifting, cycling sprints).

However, while some studies have found statistically significant improvements in exercise performance and recovery, others have shown minimal or no effect, especially for endurance exercise. The variability may relate to differences in dosing, participant fitness, and exercise protocols. Overall, moderate evidence supports L-citrulline’s use as an exercise aid, particularly for enhancing anaerobic performance and reducing fatigue, but more large-scale, long-term studies are needed to establish optimal dosing and clarify its benefits across different types of exercise.

More about L-citrulline
More about Athletic and Exercise Aids

Other ingredients used for Athletic and Exercise Aids

Other health conditions supported by L-citrulline

Products containing L-citrulline

Douglas Laboratories Cysto Renew ®
Pure Encapsulations Nitric Oxide Support
Pure Encapsulations Nitric Oxide Ultra
Designs For Health NOx Synergy™