Monosodium glutamate (MSG) is a salt form of an amino acid that is used in food preservation and flavoring. It has been noted that MSG can trigger headaches in susceptible people. It is frequently added to oriental foods as flavoring and is found in many processed meats and canned goods. Reactions can occur as early as 30 minutes after ingesting MSG, which is rapidly absorbed in the stomach. Chinese food often contains MSG and the orginal description of the condition was called "Chinese Restaurant Syndrome".
MSG reaction can cause other symptoms such as perspiration and tightness and pressure over the face and chest. Research has suggested that the effects of MSG may be minimized or avoided by countering these effects by consuming at least one cup of a complex carbohydrate, such as rice or pasta, as part of the meal.
In most instances, monosodium glutamate (MSG) will be included on food packaging or can labels.