From the Manufacturer's Label:
L-Citrulline is a natural amino acid that supports sports performance and good health, while at the same time helping the liver detoxify. L-Citrulline helps the body rid itself of ammonia, a by-product of intense exercise. This clearing enables the body to recover after a workout, and it frees ATP energy for enhanced uses such as respiration and signal transduction.**
Contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.