The study was designed to explore the beneficial effect of Musca domestica larvae extract (MDLE) on a metabolic disorder using a diabetic rat model. Streptozotocin-induced diabetic rats were treated with or without MDLE. Blood glucose, insulin levels, lipid profiles, and oxidative stress markers were measured. The morphological changes in the pancreas and liver were determined, as well as insulin expression. The expression of glucose transporter 4 (GLUT4), phospho-adenosine monophosphate-activated protein kinase (p-AMPK)/total AMPK, superoxide dismutase 1 (SOD1), catalase (CAT), and peroxisome proliferator-activated receptor gamma (PPARγ) were detected. Compared with untreated diabetic rats, MDLEtreated rats had decreased urine volume, food intake, and water intake, along with significantly lower levels of blood glucose, malondialdehyde (MDA), plasma triglycerides, low-density lipoprotein (LDL), and total cholesterol. MDLEtreated rats also had higher levels of SOD activity, high-density lipoprotein (HDL), and insulin. MDLE treatment partially restored the β-cell population, improved the liver necrosis and islet cell damage, reversed the decreased expression of GLUT4, phospho-AMPK, SOD1, and CAT in the liver, skeletal muscle and pancreatic tissue, and also increased the expression of PPARγ in the liver and adipose tissue in diabetic rats. In conclusion, the obtained results suggest that MDLE could possibly be used pharmacologically as an adjuvant for the treatment of diabetes.