The research and development of cosmeceuticals is booming in recent years. Many substances, either from botanical, animal, or chemically synthesized sources, are tested or investigated as the active ingredients in cosmeceuticals. The interactions between cosmeceuticals and skin are complex, depending on the specific composites in cosmeceutical products, condition of the skin or general health status of a subject, and the environment where the action occurs. As such, careful preclinical or clinical evaluation of efficacy and safety is a prerequisite for the development of a specific cosmeceutical product. This article reviews some of the ingredients that are currently in use or might be potential candidates in cosmeceuticals of different categories.