Methionine is a sulphur-containing amino acid, and together with cysteine they are the main source of sulphur in our diet. The body uses amino acids to build proteins, or building proteins. Methionine is an indispensable amino acid that the body is unable to produce itself, so we should get it from the food we eat. Methionine is converted in the body into cysteine, carnitine, glutathione, taurine and nucleic acids. The role of methionine is thought to be important in tissue growth and regeneration, and especially in trauma and injury. It has also found use in detoxification, as methionine can help neutralise chemicals and toxins. In such cases, supplementation with B vitamins is recommended.