Moisturizers serve one purpose. That's moisturizing and taking good care of your skin. Some products, like alcohol sanitizers, are mixed with moisturizers so they don't dry your skin. This is great for nurses who have to sanitize their hands several times a day. Add hand creams also double the moisturizers. They add moisture inside the skin and trap this moisture with an oil layer on top of it. This is more common among water-based hand creams that penetrate deep into the skin and anti-aging creams that are meant to be absorbed.