Mangosteen extracts have shown in laboratory tests that they can stop certain bacteria and fungi from growing. One laboratory study suggested that mangosteen extract inhibits the growth of acne causing bacteria. It has not been tested on people to determine whether it can help acne. In the laboratory, it also slowed the growth of certain cancer cells. A small study in rats suggested that the rind of the mangosteen may reduce the risk of cancer cell growth in the bowel. However, the ability of mangosteen to inhibit cancer growth has not been tested in humans.