L-Citrulline

L-citrulline is an intermediate in the urea cycle, with core functions including:

NO metabolism and vasodilation:

• By converting to L-arginine, the level of nitric oxide (NO) is increased, endothelial function is improved, and blood pressure is lowered (such as in adjuvant therapy for mild hypertension).
• Enhance exercise tolerance (reduce fatigue), used for exercise supplements (more easily absorbed than arginine).

Ammonia excretion and detoxification:

• Promote urea circulation and help clear blood ammonia (beneficial for cirrhosis or hyperammonemia).

Other potentials:

• May improve erectile dysfunction (ED) (better when combined with arginine).
• Antioxidant effect (by regulating the arginine/NO pathway).

Safety: High doses (>10 g/day) may cause gastrointestinal discomfort.