MSG sensitivity is a set of symptoms that may occur in some people after they consume monosodium glutamate (MSG). The syndrome was first described in 1968 as a triad of symptoms: “numbness at the back of the neck radiating to both arms and the back, general weakness and palpitations.”¹

MSG is used worldwide as a flavor enhancer. Although many restaurants now avoid the use of MSG, many still use significant amounts. The average person living in an industrialized country consumes about 0.3 to 1.0 gram of MSG per day. MSG is classified by the US Food and Drug Administration as “generally recognized as safe.” Indeed, many researchers have questioned the very existence of a true MSG-sensitivity reaction. Most clinical trials, including some double-blind trials, have failed to find any symptoms arising from consumption of MSG, even large amounts, when taken with food.^{2, 3, 4, 5, 6} However, clinical trials have found that MSG taken without food may cause symptoms, though rarely the classic “triad” described above.^{7, 8, 9} A large trial and a review of studies on MSG both suggested that large amounts of MSG given without food may elicit more symptoms than a placebo in people who believe they react adversely to MSG. However, persistent and serious effects from MSG consumption have not been consistently demonstrated.^{10, 11, 12}

People sensitive to MSG may also react to aspartame (NutraSweet).¹³