The present study evaluates the oxidative stability of refined echium oil supplemented with Sophora japonica L. extract (200 ppm). Commonly used synthetic antioxidants (butylated hydroxytoluen (BHT), ascorbyl palmitate, and quercetin) are used as reference additives. The plant extract is evaluated to possess better in vitro antioxidant potential than BHT, and comparable to that of quercetin. The degradation kinetics at 6, 25, and 60°C with and without antioxidants is studied, as well as the progress of oil oxidation. The temperature dependence of oxidation is expressed with the Arrhenius equation in addition to reaction rate constant (k) and activation energy (E a) also determined using Arrhenius equation. Enthalpy of activation (H ‡), entropy of activation (S ‡), and Gibb's free energy of activation (G ‡) are calculated according to the Eyring equation. It is established that the rate constant increased with the temperature of storage. The lipid oxidation reactions are established to follow a zero-order kinetic model for peroxide value. The oxidation reaction is determined as exothermic and non-spontaneous. In conclusion, S. japonica extract is evaluated with high antioxidant potential and can be used as a promising oil stabilizer. It can successfully be added to prevent lipid structure oxidation while providing health benefits to consumers. Practical Applications: The application of natural antioxidants in edible oils in order to substitute synthetic additives is a matter of research interest. The present study aims to compare commonly used synthetic antioxidants with natural ones. Ascorbyl palmitate has the greatest ability to stabilize echium oil at 6, 25, and 60°C, but the Sophora japonica L. extract possesses good potential for retarding the oxidation. The results of this study outline the potential of the natural extract of S. japonica, which needs to be further studied.