A coconut is mainly rich in water, sugar, lipids, protein, amino acids, vitamins, minerals, and phytochemicals. These substances have shown positive benefits on both human and animal health, resulting in the reduction of the risk for several illnesses, including gastric ulcers. The main objective of this research is to determine how effectively the anti-ulcer medication omeprazole and the powdered coconut fruit and milk reduce stomach ulcers in rats. Out of the 65 rats utilized in this investigation, nine groups of six female albino rats, each weighing 150g±10g, were created. To create stomach ulcers, rats were given 300 mg/kg B.W. to induce ulcers. Gastritis, pH, acidity, length of stomach, ulcer score, ulcer index, percentage of ulceration, and preventive index were also measured in the study. Biochemical analyses included measurements of triglycerides (TG), high-density lipoprotein (HDL-c), low-density lipoprotein (LDL-c), very low-density lipoprotein (VLDL-c), liver enzymes (ALT, AST, & ALP), and oxidative enzymes (CAT, SOD, NAD, and GPx). Moreover, the HPLC method for phenolic compound identification. The results showed that the gastric ulcer group of rats exhibited considerably improved lipid fraction, liver activities, oxidative enzymes, and gastric ulcer when administered coconut fruit powder and its milk. Concluding the study, the gastric ulcer rats that were given 500 mg/kg of coconut milk showed better % of ulcer inhibition and improved biochemical analysis. This suggests that coconut fruit and milk can be used as natural dietary supplements to improve diets and reduce risk factors for chronic diseases like gastric ulcers.