Occlusives, Humectants and Emollients
Before you can narrow down the best type of moisturizer for your skin, we first need to understand a few things about how moisturizers work.
Moisturizers hydrate and smooth the skin. There are a few types out there, but it basically breaks down to products that seal moisture into the skin, products that smooth the skin and products that attract moisture to the skin.
Occlusives and emollients soften and smooth the skin. Occlusives include petroleum jelly, parafiin and collagen, and they work by sealing in moisture: This type of moisturizer creates a layer -- a physical barrier -- on your skin to keep moisture from escaping, similar to how all that extra sebum your body naturally produces helps seal moisture in. Emollients are oils and lipids (fats), such as stearic acid and essential fatty acids, that help to repair and smooth skin – the creamier the moisturizer, the more emollient it's said to be. Humectants such as panthenol, urea and glycerin, on the other hand, work by attracting moisture from the deeper layers of skin to the outermost layer of the skin. In humid climates, they also attract moisture from the air.
Most moisturizers rely on a combination of humectants, occlusives and emollients to attract and seal in moisture as well as improve skin texture, while also repairing and hydrating. Oily-skinned faces take note: Occlusives can be thick and are notoriously greasy, and if your skin is already oily, these ingredients can trap sebum and cause blemishes.