There are dozens -- maybe even hundreds -- of skin moisturizing products lining the shelves of your local store, each touting a unique set of assurances and benefits. Thankfully, you don't need an advanced degree in dermatology to find a skin care product that works for you. You just need to know a few things about two types of moisturizers: occlusive and humectant.
Occlusive moisturizers prevent water from leaving the stratum corneum by acting as a waterproof film that covers your skin. Because they're typically made up of oil-rich ingredients, such as petroleum, various mineral oils or silicone, these moisturizers may clog pores, irritate the skin and cause breakouts [source: Skin&Aging]. Therefore, occlusive moisturizers don't work very well for people with sensitive or oily skin. For everyone else, however, they offer an effective way to retard your skin's natural water loss.
Humectant moisturizers are great for those of us with habitually dry skin or for people whose skin is oily, as they're water-based and contain very few oils. Humectants work by absorbing and retaining water from the air and lower layers of your epidermis. Because they add moisture instead of just trapping the water that's already there, humectant moisturizers help prevent dry skin from cracking by increasing its natural pliability and flexibility. If you're looking for a humectant moisturizer, check for ingredients such as glycerin, lactic acid, sorbitol and alpha hydroxyl acids [source: Downie and Cook-Bolden].