High intake of monosodium glutamate (MSG) –containing foods was reported as a major health problem in Egypt. Thus, dietary interventions aim to prevent the deleterious effects of this additive were badly needed. This study was carried out to investigate the effect of concurrent consumption of MSG and Spirulina (S. platensis) on body weight as well as hepato-renal functions and histopathology in female rats. Twenty adult female albino rats were divided into four equal groups, including the control group, while groups 2 to 4 were administered 6 mg MSG/kg body weight daily, and kept untreated (group 2), or concurrently fed pelleted balanced diet supplemented with 0.5 and 1 % of Spirulina powder for 6 weeks (groups 3 and 4, respectively). At the end, body weight gain, feed intake and feed efficiency ratio were calculated. Liver and kidney functions were determined in sera, while oxidative stress markers were determined in liver and kidney tissue homogenates. Moreover, specimens from liver and kidney of sacrificed rats were histopathologically examined. On the other hand, phenolic profile of Spirulina powder was identified and quantified by HPLC. Findings indicated that MSG consumption resulted in overweight, liver and kidney dysfunction along with oxidative stress, which was further confirmed by histological staining. Due to the high content of phenolic compounds rather than other antioxidant agents, Spirulina powder exerted anti-obesity properties and alleviated the toxic hepato-renal effects caused by MSG consumption. So, dietary supplementation of MSG –containing food products with Spirulina powder is recommended to prevent its accompanied health abnormalities.