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. They increase the amount of water the stratum corneum - the outermost layer of the epidermis - can hold.

How Humectants Work

Humectants are like water magnets. They pull water from the dermis into the epidermis, and if humidity is above 70 percent, they can even draw in moisture from the air.

Humectants are extremely important in keeping skin soft and supple.

They also encourage desquamation, the shedding process, by wearing down the corneodesmosome that hold skin cells together. Humectants repair dry, cracked skin by providing maximum hydration and reducing skin irritation. They also 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 cleaners, eye creams and lip care products. There are two types of humectants: synthetic and natural.

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 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 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 on its own.

Some examples of natural humectants include:

  • Hyaluronic acid. It sounds 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 chemical, but it's a natural compound found in fruit, milk and sugar cane that encourages exfoliation and desquamation.
  • Honey. It hydrates without 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 weather is really dry, particularly during winter and in arid climates, humectants can actually pull too much moisture out of the skin. Humectants pull moisture from the deepest layers of the skin without replenishing it. Skin stays hydrated for a period of time, but skin is dry overall. Over time, this can lead to duller, drier 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.

Sources:

Del Rosso, James. "Cosmeceutical Moisturizers." Procedures in Cosmetic Dermatology - Cosmeceuticals. Ed. Zoe Diana Draelos. Elsevier, 2005. 99-102.

Johnson, Anthony. "The Skin Moisturizer Marketplace." Skin Moisturization. Ed. James J. Leyden and Anthony V. Rawlings. New York: Marcel Dekker, 2002. 7-16.

Rawlings, Anthony, et al. "Humectants." Skin Moisturization. Ed. James J. Leyden and Anthony V. Rawlings. New York: Marcel Dekker, 2002. 248-257.

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