Moisturizers are a critical part of skincare, and especially so for those with dry skin. We’ll be looking at what dry skin is, and what causes it, and how moisturizers can intervene in this process to protect the skin from drying out.
Moisturizers are the go-to skincare product for dealing with existing dry skin or to prevent dryness from occurring. It’s often our best friend during the winter or year-round for those with dry skin or a condition like eczema or atopic dermatitis.
What are moisturizers made out of, and how do they work?
Moisturizers, like other cosmetic products, are a mixture of many ingredients which serve different roles. There are three main types of ingredients that help the skin retain moisture. Many other ingredients play a supporting role, like keeping the product fresh and intact or adding or removing the scent. The main working horse ingredients of moisturizers are, however: Humectants, Occlusive agents, and Emollients.
Humectants are ingredients that attract moisture. When applied to the skin, humectants draw moisture from the lower layers of the skin to the surface. Additionally, if the outside air has sufficient humidity, it also draws moisture from the air. The tight, parched sensation of dry skin occurs when there is insufficient moisture at the stratum corneum, and humectants aim to increase moisture here.
Humectants help increase the skin’s flexibility as it gains moisture and reduces irritation and itching, associated with lower moisture levels. Glycerin, urea, and PCA are common humectants used in moisturizers to help the skin retain moisture.
A certain amount of moisture is naturally lost due to evaporation and diffusion. This water loss is influenced by various outside factors like temperature and humidity levels and the person’s skin health. This natural but unavoidable process of water loss is called transepidermal water loss or TEWL. Occlusive agents are ingredients that physically block water from leaving the skin; they help seal the moisture inside the skin. This is why applying moisturizers immediately after a shower or bath while the skin is still moist is most effective.
Petrolatum, silicone, wax, and various oils are popular ingredients that are used in moisturizers. They are used as occlusive agents. Generally, the more powerful moisturizers have a high concentration of these ingredients. A common concern is that many people don’t like the sticky consistency of occlusive agents.
Emollients are ingredients that help provide a seal on the skin, similar to occlusive agents, and help smooth out the surface of the skin. The surface of the skin has many dead cells which can form rough patches. Emollients help smooth and soften the skin. Some popular examples of emollients include Cetearyl alcohol, isopropyl myristate, and lanolin.
There are a variety of ingredients with varying properties and effectiveness. Many of these ingredients are a trade-off between efficacy and other considerations like stickiness and consistency. Finally, there are also aesthetic and financial considerations that come into play, as some ingredients cost more than others.