6,8-Disubstituted-9-(heterocyclyl)purines for use in pharmaceutical and cosmetic compositions and applications are provided. These 6,8-disubstituted-9-(heterocyclyl)purines have a wide range of biological activities, including for example antioxidant, anti-inflammatory, anti-senescent, anti-aging, as well as well as other activities which are especially useful in pharmaceutical and cosmetic applications. Compositions may include additional excipients and auxiliary substances. Methods of treatment of animals, mammals, plants, cells, yeast, and cells in tissue culture are also disclosed.