The safety and toxicity of the flavor enhancer monosodium glutamate (MSG) remains unclear given conflicting scientific toxicological reports. MSG has been associated with causing nausea and headaches in humans and producing deleterious effects on laboratory animals. The aims of this study were to evaluate the negative effects of MSG and investigate the beneficial, protective effects of the dietary supplement spirulina (spirulina platensis) on biochemical parameters of blood. Specifically, this investigation considers the damage sustained by organs of Swiss mice after supplementation of MSG daily over the course of four weeks. During the experiment, the control group (I) received only animal feed and drinking water; group MSG-1 (II) received 1 ml of MSG; group MSG-0.5 (III) was treated with 0.5 ml of MSG; and group MSG-S (IV) was treated with 1 ml of MSG and 1 ml of spirulina (aiming to combat the MSG toxicity). The results of this study showed that MSG generated histopathological changes in the subjects’ kidneys and caused significant (negative) changes for all studied biochemical parameters of the blood serum (ALT, AST, GLU, CRE, COL, TG), observed in both the MSG-0.5 and MSG-1 groups. The MSG-S group, animals treated with MSG in combination with spirulina, demonstrated the beneficial effects of spirulina, mitigating the observed effects of MSG toxicity. In this group, mice did not show histopathological changes of the organs and the biochemical parameters presented average values similar to the control group. Seeking to explain how the spirulina protected against the MSG, IR spectroscopy was used to investigate the molecular interactions. It was observed that the introduction had a notable effect on IR spectrum, suggesting a possible mechanism for the observed beneficial effects of spirulina.