Betaine HCI is used to supplement hydrochloric acid to the stomach in cases of gastric acid insufficiency. Sufficient hydrochloric acid is essential for the function of pepsin, the major protein digesting enzyme of the stomach. Betaine itself is a methyl donor. Betaine can decrease blood homocysteine levels, enhance glutathione and active methionine (SAMe) levels, and aid the liver to detoxify alcohol and other poisons. It is a liptrope, because it can prevent the deposition of fat in the liver.