Introduction: In addition to exercise and diet, medications also have a special role in weight loss. The aim of this study is to evaluate the effects of Slim-quick herbal medicine and Fat Stop synthetic medicine, and compare these two with the serum levels of ghrelin and neuropeptide Y hormones as well as the body weight changes in adult female rats. Methods: In this experimental study, 32 adult female Wistar rats were divided into 4 groups of 8, including control group - slim-quick 200 mg/kg, Fat stop 200 mg/kg, and simultaneous recipient group - slim-quick 200 mg/kg, Fat stop 200 mg/kg. Slim-Quick and Fat-Stops were fed to animals by gavage. In the 29th day after the start of the experiment and weighing of the animals, blood sampling was performed from the heart and the serum concentration of the ghrelin neuropeptide Y was measured. The results were analyzed by ANOVA and Duncan tests at a significant level of p≤0.05. Results: the decrease in serum levels of ghrelin and neuropeptide Y and weight loss was significantly higher in the simultaneous recipients of Slim-Quick and Fat-Stop than the separate recipients of the two medicines. Conclusion: Simultaneous application of Slim-Quick and Fat-stop reduces the body weight by decreasing the serum levels of orexigenic ghrelin hormone and Y neuropeptide.