Monosodium glutamate is one food enhancer which enhance flavor, originally used for meat and savory dishes, however these days it’s used in a wide array of foods or ‘food like’ products. Its toxic effects have been shown in numerous animal studies, however in most of them, the method of administration and the doses were not similar to human MSG intake, in this paper the review is highly focused on the side effects of MSG which affect CNS, causes abnormalities in liver, gastric problem, obesity, increased ROS in cell and effects on reproductive organs were discussed.