L-citrulline powder

L-citrulline is a non-protein amino acid involved in arginine synthesis. Nitric oxide and L-citrulline are synthesized from the amino acid L-arginine and through the action of an enzyme (nitric oxide synthase). Nitric oxide is an intermediary molecule in vasodilation and regulates different functions in skeletal muscle, such as glucose intake, blood flow and contractile function¹.

L-citrulline is a powerful precursor of L-arginine, and L-citrulline supplementation has been reported to be more efficient in increasing arginine levels in the body than supplementation with L-arginine itself^{1, 2}, due to is greater bioavailability³. One study comparing the effects of supplementation with L-citrulline and arginine on the biomarkers of nitric oxide, physical performance and oxygen consumption (VO₂), concluded that in the short-term, supplementation with L-citrulline improved blood pressure, oxygen consumption and physical performance, compared with arginine supplementation⁴.

Various studies have shown that continued L-citrulline supplementation increases the synthesis of nitric oxide, reduces blood pressure and may increase peripheral blood flow. This has been linked to an improvement in skeletal muscle oxygenation and performance during resistance exercise⁵.

Finally, citrulline may also help avoid exercise-induced central fatigue in combination with BCAA and arginine⁶. It has been found that both L-citrulline and L-arginine may reduce the accumulation of ammonia (which is linked to physical exercise and can induce central fatigue) by increasing the synthesis of urea and nitric oxide³.

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