Free radicals continue to be produced in our body. Free radicals attack lipids and produce lipid hydroperoxide. Aggregated lipid peroxides are known to be a risk factor for developing various diseases such as arteriosclerosis and cancer. Antioxidant enzymes such as SOD and CAT that exist in the body are not sufficient to prevent these problems. Therefore, we consume antioxidants such as vitamins. Therefore, in this study, we reexamined the antioxidant activity of Twendee X, which is commonly sold as a multi-supplement [1]. In this experiment, electron spin resonance (ESR) was used to measure antioxidant activity. ESR is the only measurement method that can directly measure radicals. The results showed that Twendee X has very strong antioxidant activity. The ingredients contained in Twendee X are mainly water-soluble vitamins and amino acids. Despite this, it is surprising that Twendee X has the ability to scavenge hydroxyl radicals and superoxide radicals. This time, we will present a comparison of its antioxidant effect with other antioxidants. As future research progresses, we may be able to discover new combinations of vitamins and amino acids that strongly scavenge many types of radicals. Furthermore, if the relationship between individual radicals and disease and fatigue is clarified, it may become possible to create custom-made supplements.