Chinese restaurant syndrome is a collection of symptoms that some people experience after eating Chinese food. A food additive called monosodium glutamate (MSG) has been implicated, but it has not been proved to be the substance that causes this condition.

In 1968, reports of a series of reactions to Chinese food were first described. MSG was reported to cause these symptoms, but subsequent research produced conflicting data. Many studies were performed, but a majority failed to show a connection between MSG and the symptoms that some people describe after eating Chinese food. For this reason, MSG continues to be used in some meals. However, it is possible that some people are particularly sensitive to food additives, and MSG is chemically similar to one of the brain's most important neurotransmitters, glutamate.