The cosmetic isles in every store are amok with products that boast their age defying powers and skin solution capabilities.  With so many choices, how do you begin to choose the brand that is best for you? To begin with, it is important to note that moisturizers can be categorized into four different types; occlusives, humectants, emollients and rejuvenators. Occlusives prevent evaporation from the skin by forming a layer on the surface of the skin that repels water and provides an external barrier to water loss. On the contrary, Humectants work to increase the water content of the skin by enhancing water absorption from the protective outer layer of the skin into the epidermis. The third class of moisturizers, emollients, fill in any spaces or gaps between skin cells that are missing moisturizing lipids,  such as fats and oils. Finally, rejuvenators are designed to replace crucial proteins in the skin. (Source: Nolan, K. and Marmur, E. (2012), Moisturizers: Reality and the skin benefits. Dermatologic Therapy, 25: 229–233.   When choosing between these various groups of moisturizers there are several factors to take into consideration. First, consider the environment that you live in. Occlusives are most effective in humidity void regions while humectants, which absorb water from the air, depend upon high humidity levels.  When browsing for moisturizers, keep in mind  that lotions, such as Spezial Lotion D by Peter Greven,  are droplets of water mixed in oil, meaning that they have a high oil to water ratio and work well in the warm, humid summer months. Creams, such as Lindesa and Spezial Creme C,  on the other hand, have a high water and low oil content and are best used during the winter months, as they create a layer of oil that locks moisture in. The water does not evaporate and the skin stays hydrated. (Source: Jeffrey Benabio, MD) In addition, age, genetics, hormones and ethnicity all play a role in determining your skin type and consequently, the type of moisturizer that will ultimately work best for you.