DL-Methionine methylsulfonium (DL-MMSC), a racemic mixture, is used to study its mechanism of protection against gastric ulceration. DL-MMSC may also be used as a methionine analogue. S-Methionine methylsulfonium (SMMS) chloride is a derivative of methionine metabolism in some plants. SMMS has potent therapeutic effects on gastrointestinal ulceration potentially via its ability to promote dermal fibroblast migration and growth.