Mangosteen Tea is a dietary supplement made from the antioxidant-rich mangosteen. The mangosteen is an exotic fruit from Southeast Asia that offers several classes of powerful phytonutrient antioxidants. One of the most beneficial aspects of the mangosteen is the xanthones it contains. Xanthones are biologically active plant phenols structurally similar to flavonoids that possess antioxidant properties to help seek out and destroy roaming free radicals that can wreak havoc on good health.