How Do Creams, Lotions, Oils, and Serums Work?

Hydration is the amount of water within your skin cells, as a result of your daily intake of water, climate, humidity, etc. Skin care ingredients that hydrate include hyaluronic acid, glycerin, and aloe. Skin that is dehydrated will not respond well to a moisturizer. The best way to hydrate the skin, besides drinking enough water, is by using a penetrating serum.

Hyaluronic acid naturally occurs in our bodies. It lubricates and hydrates joints, eyeballs, and skin, and is considered a ‘super humectant’, with a capacity to hold up to a thousand times its weight in water. Glycerin is a natural ingredient that works to balance water in cells and as a skin care ingredient glides on smoothly and locks in water. Aloe is also a humectant, penetrating deeply and quickly to hydrate the surface layers of skin as well as the lower layers.

Moisturizing is the process of adding water, oils, and nutrients to the top layers of skin. Most important in this process is replenishing the skin’s lipid barrier, which is made up of natural fats and oils. A healthy lipid barrier minimizes skin water loss and keeps micro-organisms and irritants from penetrating to the lower layers of skin where they may create free radical cells. Moisturizing is the hallmark of skin care and helps keep skin smooth, soft, and supple.

Emollients help skin hold on to moisture. The best emollients have medium-to-long-chain hydrocarbons, which include linoleic, linolenic, oleic, and lauric acids, such as are found in coconut oil, hemp seed oil, shea butter, and argan oil. Emollients form a thin, protective layer over the skin and provide some protection from UV rays. Coconut oil, for example as a natural spf level of 5-6.

Lotions contain mostly water and moisturize quickly but don’t last long. To get the most out of a lotion, apply it immediately after a shower or bath to lock in the skin’s moisture. Lotions work on the upper layers of the dermis and tend to be short lasting, which is why they require frequent application.

Creams can be water-based or oil-based, which is simply a reference to the dominance of either in the formulation. Most creams contain both water and oils and moisturize more deeply and thoroughly than lotions but can be too heavy for some applications and skin types. A good facial cream contains hyaluronic acid or glycerin to hydrate the skin, water to moisturize, and oils to lock in the moisture, nurture and protect.

Serums penetrate more deeply than creams or lotions and if properly formulated act on multiple skin care concerns simultaneously. Serums are used to reduce wrinkles and slow down the visible signs of aging. They’re also used to treat acne and other challenging conditions. A good serum contains water, oils, hyaluronic acid or glycerin, peptides, and antioxidants to lessen the buildup of free radical cells.

Oils contain no water and don’t moisturize in the strict sense of adding water to the skin, but they contain nutrients and antioxidants that are very beneficial to the skin. Oils are most effective when applied over damp skin, such as after a shower or bath, locking in the moisture. An oil can be a moisturizer, occlusive, or emollient depending on its qualities. Penetrating oils like argan oil do all three. Vaseline is a prime example of an occlusive that coats and protects the skin without moisturizing at all. Heavier oils like olive and coconut oil can act the same way. Oils complement the skin’s natural oils and nourish, lubricate, and strengthen the skin’s protective lipid barrier.

Non-comedogenic oils penetrate deeply without clogging pores. Examples are argan oil, hemp seed oil, grape seed oil, sunflower seed oil, and jojoba oil. Jojoba oil has a molecular structure very similar to the sebum in skin, so it’s particularly adapt at nourishing the skin and lipid barrier. Non-comedogenic oils can also help dial down the skin’s sebum production, which can be good for controlling acne since the skin no longer has to overcompensate for a lack of oil.