Diabetes Mellitus (DM) is a major health problem worldwide. DM with poor control of blood glucose levels can eventually cause pancreatic cell disorders, including a decrease in cell mass and function. Mangosteen rind contains xanthone compounds that can be used to protect and reduce cell damage, especially those caused by free radicals. This study aimed to analyze the effect of mangosteen peel on decreasing blood glucose in a streptozotocin-induced diabetes mellitus model.