Abstract: Background and Objective: The evidence for safe consumption of chili pepper to gain health benefits is insufficient as high doses reported to cause gastric erosion. The objective of this study was to investigate the contribution of red chili pepper ethanol extract (RCEE) to weight loss in high fat dieted female albino Wistar rats while monitoring adverse effects of high dose consumption. Materials and Methods: Body weight gain, lipid profile, oxidative stress parameters, liver, kidney and thyroid biochemical functions were determined in addition to histopathological examination of liver and kidney to determine biological effects of 2 ingested concentrations of red chili pepper extract (5 and 10 mg). Results: Red chili pepper ethanol extract (RCEE) showed anti-obesity potentials and hypolipidemic effects through decreased levels of total cholesterol (T.Ch), low density lipoprotein (LDL), triglycerides (TG) and very low density lipoprotein (VLDL) reached 25, 55, 45 and 45%, respectively, in parallel with increased high density lipoprotein (HDL) levels by 22.6%. The antioxidative potentials of RCEE were pronounced through significant increases in glutathione peroxidase (GPx) and catalase (CAT) activities (346.43 mU mL–1 and 15.33 U L–1 in group 2, respectively). Histological examination of liver and kidney showed adverse results but that did not significantly reflect on their functional biochemical parameters. Conclusion: Results introduced scientific evidence that red chili pepper possesses functional pharmacological properties but the excessive consumption induces liver and kidney damage.