Chemotherapy drugs used in the treatment of ovarian cancer work, in part, by inducing even higher levels of oxidative stress to attack cancer cells. This increased oxidative stress also causes chemotherapy related side effects. Oncologists have been concerned that antioxidants, which can decrease oxidative stress, can therefore also decrease chemotherapy treatment effectiveness or increase resistance to chemotherapy. However, no substantial clinical research has emerged to support the assertion that antioxidants are contraindicated during chemotherapy.