Denosyl, a nutritional supplement, is the pure and stabilized salt of S-Adenosylmethionine for veterinary use only. Denosyl has been shown to increase hepatic glutathione levels in cats and dogs. Glutathione is a potent antioxidant that protects hepatic cells from toxins and death. A study found that low liver glutathione concentrations are common in dogs and cats with decreased hepatobiliary function. Denosyl is recommended to improve hepatic glutathione levels in patients to help maintain and protect liver function. Denosyl may also be used in other areas of tissue oxidant injury and RBC fragility caused by certain toxins or drugs which are related to reduced glutathione concentrations.