This study was performed to examine the progress of hypercholesterolemia as a result of an elevated cholesterol diet and to estimate the impact of L-carnitine and garlic oil on serum lipid profiles, serum free fatty acids (FFAs), glucose, serum insulin, serum insulin resistance, serum malondialdehyde (MDA), and liver homogenates for glutathione and liver lipid percentages. Two hundred eighty-eight adult male albino rats were divided into four groups as follows: control group, high cholesterol diet (HCD) group received 1 g, 2 g, and 3 g cholesterol /Kg of paddy feed for 8 weeks , protective group (fed HCD either with L-carnitine at a dose of 200 mg/kg. BW per diem or garlic oil at a dose of 28 mg/kg. BW. per diem for 8 weeks), and treated group was fed on HCD for 4 weeks, then after that treated by L-carnitine or garlic oil for another 4 weeks. In protective groups (L-carnitine and garlic oil supplementations with HCD)> the obtained results revealed a significant decrease in serum total cholesterol (TC), triacylglycerols (TG), low-density lipoprotein-cholesterol (LDL-C), very low-density lipoprotein-cholesterol (VLDL-C), FFAs, MDA, glucose, insulin and insulin resistance. Also, revealed a significant decrease in liver lipid percent and oxidized glutathione and significantly increase in serum high-density lipoprotein-cholesterol (HDL-C), liver total glutathione and reduced glutathione. In treated groups, our results affirmed a significant decrease in serum total cholesterol, triacylglycerols, HDL-C, FFAs, MDA, liver lipid percent and oxidized glutathione and significantly increase in liver reduced glutathione (GSH). In addition, our results showed a significant increase of serum LDL-C, VLDL-C, glucose, insulin, and insulin resistance. Based on the results of experiments, it is cleared that garlic oil is more effective than L-carnitine..