People in the fast-food era rely on pre-packaged foods and engage in limited physical activity, which leads to a shift in eating patterns. Monosodium glutamate (MSG), a dietary ingredient used in this sort of cuisine, has been found to be hazardous to both experimental animals and humans. The objective of this study was to explore at the unnecessary changes caused by consuming MSG in secret and exceeding the recommended dosage. Hence, we decided to evaluate the impact of MSG by using three different doses (200, 400, and 600 mg/kg body weight orally) for 28 days in rats. We uncovered that all three MSG dosages result in a rise in body weight, dyslipidemia, inflammatory response, and hepato-cardiac marker enzymes, all of which imply hepatic and cardiac toxicity. Furthermore, changes in redox status suggest oxidative stress, which was higher in all three MSG dosages although not as much as in the MSG-600 group when compared to control. Such effects eventually manifested themselves in tissue architecture of the liver and heart, resulting in severe hepato-cardiac derangement, but the degree of tissue damage was greater in the MSG-600 group. As a result, it is possible that MSG has a negative influence on the liver and heart. However, the MSG-600 group showed a substantial effect, indicating that MSG should not be used in food preparation. Therefore, the findings of the study may aid in the formulation of health-care strategies and serve as a warning to the general public regarding the use of MSG in daily diet.