While there are those who consider Mangosteen to be a primary cancer treatment, this Cancer Tutor website considers Mangosteen to be a primary cancer treatment only for newly diagnosed cancer patients. For advanced cancer patients this treatment is considered a highly recommended supplemental protocol. Mangosteen provides critical nutrients to the non-cancerous cells and will likely kill many cancer cells. But this website does not consider it strong enough to be a primary treatment for advanced cancer patients.
Various studies have shown that phytoceuticals in Mangosteen (in some cases known to be its xanthones) have properties such as: anti-tumor (shrinks tumors), anti-leukemia, antifungal (critical for all cancer patients), antibacterial (to protect DNA), antioxidants (at least two dozen different kinds of xanthones are in the mangosteen fruit), antiproliferation, kills cancer cells and causes apoptosis (programmed cell death) for some types of cancer. This is a pretty impressive list of cancer credentials.