Oxidative stress is a major inducer of chronic diseases including atherosclerosis, Alzheimer’s disease, diabetes and cancer. New nano-antioxidants can combat oxidative stress, but they were not well characterized against each other or with natural antioxidants. My objective was to characterize and investigate which natural and nano-antioxidants were most efficacious against oxidative stress, among 4 natural antioxidants: Catechin in GreenTea, Allicin in Garlic, Glutathione, VitaminC, and 3 nano-antioxidants: MitoQ, Carbon60, Gold-Nanoparticles, using Saccharomyces cerevisiae as model organism. I hypothesized that GreenTea is the best natural antioxidant with large resonance, and MitoQ is the superior nano-antioxidant targeting ROS at mitochondria. The antioxidants were tested in 5 concentrations against hydrogen peroxide-induced oxidative stress in yeast, (1.56 to 25mg/ml for natural antioxidants, and 0.03125 to 0.5mg/ml for nano-antioxidants) and compared with 3 controls of yeast, yeast with antioxidant, and yeast with hydrogen peroxide. The yeast optical density for each solution was measured using a handheld colorimeter, before and after 24 hours. 3 trials were conducted for each antioxidant, each trial comprising these 8 solutions, and 5 samples each. Results showed GreenTea and Carbon60 were the most efficacious natural and nano-antioxidants, which counter oxidative stress at 3.125mg/ml and 0.25mg/ml respectively. Garlic, Glutathione and VitaminC displayed pro-oxidative damaging effects. GreenTea excelled because of its large polyphenol resonance and performs hydrogen-atom-transfer efficiently. Carbon60 fullerene comprises extremely stable 60-interlinked carbon molecular structure, targets mitochondria, and is less susceptible to degradation. Hence Carbon60, combined with GreenTea into a novel super-antioxidant, could be a promising therapy for oxidative stress-induced diseases.