Sunflower oil is an oil that is prone to oxidation due to its chemical structure and prevention of such oxidation is widely studied. This study assessed the the effectiveness of  gama glutamyl cyctein (GC) and glutathione (GSH), in preventing oxidation of sunflower oil stored at 50°C for a period of 15 days. Tertiary hydroquinone (TBHQ) was used as a control. Oxidation level indicators such as peroxide (PV), free fatty acidity (FFA), p-anisidine (p-AV) but also total oxidation (Totox), colour (L*, a*, b*) and free fatty acid profile were determined. At the end of storage, oxidation in sunflower oil was substantially reduced by 40 mg/L of GC. Analysis with 2,2-diphenyl-1-picrylhydrazyl (DPPH) resulted in the following order of antioxidant activities: TBHQ>BHA>GC>GSH>BHT. The samples resistance to the generation of primary and secondary oxidation products was T>GC+T>GC>GSH+T>GSH>C for up to 15 days under storage conditions. The free fatty acid profile analysed by GC/MS further demonstrated that these thiols outperformed the control group in terms of performance. Findings demonstrated that GC, precursor of GSH, has stronger antioxidant activity than GSH. As a result, it is recommended to be explored as a potential source of antioxidants in applications for the food industry to prevent lipid oxidation.