Gelatin contains a small amount (about 10%) of glutamate, which could trigger reactions in those sensitive to glutamate or MSG consumption. Glutamate which when consumed in high doses, can act as an excitotoxin or neurotransmitter known to kill brain cells. Certain people claim to experience headaches when consuming glutamates, as well as other averse symptoms like muscle tightness, numbness, tingling, weakness and flushing. Studies have not been able to consistently reproduce these effects in a controlled setting.