Thymol, a monoterpene, obtained from thyme oil or other volatile oils, is used as a stabilizer in pharmaceutic preparations. It has been used for its antiseptic, antibacterial, and antifungal actions to help reduce and prevent plaque and gingivitis. Recently was shown, that this substance was able to significantly reduce the oxidative stress associated with cataract. The results suggested that thymol might be a potential therapeutic approach in the prevention of diabetic complications through its aldose reductase enzyme inhibitory and antioxidant activities.