Moisturizers in Skin Care Moisturizers are a very important part of dermatology since keeping the skin moist is one of the key factors in healthy skin. Most moisturizers available are composed of some formulation of oil and water, with added ingredients that may or may not help to combat specific skin problems. However, moisturizers are only capable of keeping moisture from escaping out of the skin, not putting moisture back into the skin. The most effective moisturizing emollient available for dry skin is petrolatum or Vaseline, which provides a coating over the skin through which water cannot escape. Unfortunately, because it is greasy, not many people like to use it.
Ointments are usually like petrolatum, since most have an oily base.
They are also very greasy and are usually used at bedtime rather than during the day. Moisturizing creams contain more oil than water and, as a result, are also very effective. These also may feel a little greasy, but less so than ointments or petrolatum. Lotions are the most popular moisturizer, but because they contain more water than oil, they are not as effective. Humectants are a class of moisturizers which do not contain oil and may be classified as oil-free.