The article discusses the double-edged effects of exogenous antioxidants, focusing on their health benefits at physiological doses and potential deleterious effects at high doses. It highlights the importance of maintaining a balance between oxidation and antioxidation to prevent oxidative stress, which can lead to various diseases. The review covers the role of endogenous and exogenous antioxidants, including vitamins C and E, carotenoids, and polyphenols, and their sources from dietary foods and supplements. It emphasizes that while these antioxidants are crucial for maintaining cellular redox homeostasis, high doses of isolated compounds can be toxic due to their prooxidative effects or interference with beneficial ROS levels. The article also discusses the impact of metal ions and pH on the antioxidant properties of compounds, as well as the complex interactions between different antioxidants and ROS. Epidemiological and experimental studies are cited to support the findings, showing that the health benefits of antioxidants are often observed when consumed within their natural food matrices rather than as isolated supplements. The conclusion underscores the importance of considering the natural matrix and synergistic actions of complex mixtures of phytochemicals and nutrients when evaluating the health effects of antioxidants.The article discusses the double-edged effects of exogenous antioxidants, focusing on their health benefits at physiological doses and potential deleterious effects at high doses. It highlights the importance of maintaining a balance between oxidation and antioxidation to prevent oxidative stress, which can lead to various diseases. The review covers the role of endogenous and exogenous antioxidants, including vitamins C and E, carotenoids, and polyphenols, and their sources from dietary foods and supplements. It emphasizes that while these antioxidants are crucial for maintaining cellular redox homeostasis, high doses of isolated compounds can be toxic due to their prooxidative effects or interference with beneficial ROS levels. The article also discusses the impact of metal ions and pH on the antioxidant properties of compounds, as well as the complex interactions between different antioxidants and ROS. Epidemiological and experimental studies are cited to support the findings, showing that the health benefits of antioxidants are often observed when consumed within their natural food matrices rather than as isolated supplements. The conclusion underscores the importance of considering the natural matrix and synergistic actions of complex mixtures of phytochemicals and nutrients when evaluating the health effects of antioxidants.