The increase of reactive oxygen species (ROS) in the human body, through the induction of oxidative stress, can lead to cellular damage and the development of chronic diseases. Medicinal plants, due to their rich content of phenolic and flavonoid compounds, are important natural sources of antioxidants that can help mitigate these detrimental effects. An effective strategy to counteract such damage is the use of natural antioxidants, particularly those derived from various plants. In recent years, the phenomenon of synergism in the combination of plant extracts and essential oils has attracted researchers’ attention as an innovative approach to enhance antioxidant activity. The chemical composition of plants can change depending on post-harvest processing conditions, including the selection of relevant drying methods, which can also influence their synergistic effects. This study aims to review previous research on the synergistic effects of combined plant extracts and essential oils in boosting antioxidant capacity. The results indicate that combining extracts and essential oils with different chemical profiles leads to a significant increase in antioxidant activity compared to their individual use. This synergistic phenomenon allows for dose reduction and increased efficacy and has broad applications in the pharmaceutical, food, and agricultural industries. The results of this review can contribute to the advancement of natural product development by promoting formulations with improved efficacy and enhanced biological activities.
