Antioxidants are used to retard oxidative processes and improve the sensory and nutraceutical quality of cooking oils. Isoespintanol, a monophenol isolated from Oxandra cf. xylopioides, has shown a greater free radical scavenger ability than thymol (biosynthetic analog). Isoespintanol antioxidant capacity was evaluated and compared to butylated hydroxytoluene (BHT). Cytotoxicity, thermal stability and effect on olein stability studies were performed. The results revealed that Olein oxidation time was reduced 17.2 and 4.2% in the presence of Isoespintanol and BHT, respectively. Thermogravimetric curves indicated higher thermal resistance for Isoespintanol than for BHT. Finally, cytotoxicity tests for Isoespintanol against murine macrophages revealed no effect on cell viability, indicating their possible use as a safe food additive.