A dietary supplement containing a green tea extract including the catechin epigallocatechin gallate and other vitamins and antioxidants, with potential antineoplastic and chemopreventive activities. The polyphenols in green tea act as antioxidants and scavenge free radicals which may inhibit cellular oxidation and prevent free radical damage to cells. In addition, polyphenols may affect enzymes involved in cellular reproduction and tumor angiogenesis by modulating angiogenic factors. Other ingredients in green tea extract-based antioxidant supplement include dry cinnamon extract, germanium, zinc sulfate, manganese sulfate, arginine, cysteine, malic acid, ascorbic acid (vitamin c), glycyrrhizinic acid, glycine, glucosamine, pyridoxal (vitamin B6), calcium pantothenate (vitamin B5), folic acid, cyanocobalamin (vitamin B12).