AHP Vitals L arginine +citrulline 4000 mg AHP Vitals L arginine +citrulline 4000 mg is a precursor to nitric oxide. It increases nitric oxide levels, supports enhanced blood flow to your muscles for a more intense, powerful workout, and recovery. AHP Vitals L arginine +citrulline 4000 mg helps the body to retain the nitrogen that is essential to enhance protein synthesis and muscle growth. The supplement is vegetarian and is free of corn, sugar, shellfish, peanuts, binders, coatings, colorings, artificial sweeteners, peanuts, tree nuts, shellfish, and preservatives. Benefits Support blood flow and heart health. Non-gmo and gluten free. Promotes pump and vascularity. Increases enduarance. free of all top 8 allergens.