Food additives are used in practically all sorts of food preparation and processing to improve the quality of the food that we eat. MSG, or glutamic acid sodium salt, is one of the most abundant naturally occurring non-essential amino acids. Glutamic acid is a key component of several proteins, including fish, meat, milk, and many vegetables, and it is essential for human metabolism. The purpose of this study was to look into the effect of mono sodium glutamate on thyroid weight and hormone (T3,T4 , TSH ) as well as liver weight and enzymes such as GOT,GPT, total bilirubin, and ALP in male rats.