What Is a Humectant?

The Key Ingredient That Keeps Your Skin Hydrated

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Humectants are key ingredients in lotions and cleansers that hydrate the skin by attracting water like a magnet, locking in moisture. Chemically speaking, humectants form hydrogen bonds with water molecules. Humectants are extremely important in keeping skin soft and supple.

How Humectants Work

Humectants pull water from the dermis (the second and thickest layer of skin) into the epidermis (the outermost layer of skin), and if humidity is above 70 percent, they can even draw in moisture from the air.

They increase the amount of water that the stratum corneum—the outermost layer of the epidermis—can hold. This helps repair dry, cracked skin by providing maximum hydration and reducing skin irritation. 

They also encourage desquamation, the shedding process, by wearing down the corneodesmosomes that hold skin cells together. And they act as a barrier by preventing outside chemicals from making contact with the dermis.

Types of Humectants

Humectants are present in a number of different cosmetic and personal care products that provide moisturizing benefits, including hair conditioners, facial and body cleansers, eye creams, and lip care products. There are two types of humectants: synthetic and natural.

Synthetic Humectants

Synthetic humectants are quite common because they are less expensive to produce than natural humectants. They do lock in moisture to some extent, but they don't provide any noteworthy nutrients or benefits to the skin.

They essentially moisturize the skin in the short-term and dry out the skin in the long-term. Synthetic humectants include:

  • Butylene glycol
  • Glycerin
  • Urea
  • Tremella extract
  • Sorbitol
  • Dicyanamide
  • Sodium PCA
  • Sodium lactate

Natural Humectants

Natural humectants serve a dual purpose: They attract moisture to the surface of the skin and they deliver major moisture and nutrients to the deepest layers of the skin.

Natural humectants improve the skin's ability hydrate itself. Some examples of natural humectants include:

  • Hyaluronic acid. It sounds like a chemical, but it's actually a completely natural compound that exists throughout the body.
  • Aloe. This all-natural ingredient quickly penetrates and moisturizes the deepest layers of the skin.
  • Alpha hydroxy acid. This also sounds like a chemical, but it's a natural compound that's found in fruit, milk, and sugar cane and encourages exfoliation and desquamation.
  • Honey. It hydrates without giving you the oily feeling of so many other moisturizing ingredients. It also contains alpha hydroxy acids.
  • Seaweed, algae, and other marine extracts. These are naturally moisturizing remedies for dry skin.

The Problem With Humectants

When the weather is really dry, particularly during the winter and in arid climates, humectants can actually pull too much moisture from the skin. Using a moisturizer that contains occlusive ingredients can counteract this loss of moisture. Occlusives help the stratum corneum retain moisture by creating a barrier layer of oil. Occlusives are generally richer in texture and more oily by nature. They are ingredients like:

  • Mineral oil
  • Petrolatum
  • Lanolin
  • Dimethicone
  • Shea butter

Using two different types of moisturizers—a humectant and an occlusive—isn't necessarily an inconvenience. Many moisturizers already contain both. Read ingredient labels in order to know whether a product is able to deliver upon its promises.