Reports of more severe reactions to Chinese food first appeared in 1968. At that time, MSG was thought to be the cause of these symptoms. There have been many studies since then that have failed to show a linkage between MSG and the symptoms some people describe.

The typical form of MSG syndrome is not a true allergic reaction, though true allergies to MSG have also been reported.

For this reason, MSG continues to be used in some meals. However, it is possible that some people are very sensitive to food additives. MSG is chemically similar to one of the brain's most important chemicals, glutamate.