If you’ve spent any time in the consumer cosmetics space, you’ve likely been overwhelmed by the buzzwords and terminology. When you’re looking for a moisturizing product, one word that you’ll often hear: Humectant. What is a humectant? When is a humectant useful when it comes caring for your hair? Read on to learn more.
What is a humectant?
A humectant is a type of compound that’s able to both attract and retain water in order to keep something moist. The ability to attract and retain water makes a substance hygroscopic. If you’ve ever seen those tiny silica gel packets inside your shoes, electronics, or other packages, that’s an example of a hygroscopic substance being used to draw moisture away from an object, behaving as what’s known as a desiccant.
When mixed inside a product—like food, medicine, or cosmetic products like shampoos, conditioners, or pomades—the hygroscopic substance instead draws moisture toward an object as a humectant. Rather than absorption, this process is known as adsorption, meaning that water is drawn to the surface of the hair where the humectant has been applied. In some cases, water may also be drawn into the hair strand itself.
Why are humectants useful?
As we mentioned, humectants have the ability to draw in moisture from the surrounding environment and retain the moisture within. In food products, humectants like corn syrup, glycerol, propylene glycol, and sorbitol are used to keep processed foods from drying out.
In cosmetic products, humectants are useful for a similar reason. In skincare, applying a humectant to the surface of the skin draws moisture upward from the deeper layers of the skin, as well as drawing in any moisture from the air and surface of the skin itself. Retaining this moisture improves the texture and appearance of the skin and prevents drying and cracking.
In haircare, humectants are used to retain moisture within the hair strand. When formulated as part of a shampoo, conditioner, or other haircare product that’s applied topically, the humectant coats the surface of the hair strand and locks in any lingering moisture from a shower, or draws in any additional moisture from the surrounding air.
What are the positives and negatives of humectants for hair?
Humectants help to counteract any drying effects that result from surfactants present in shampoos or soaps. They also have the ability to increase the softness, bounciness, and elasticity of the hair.
On the other hand, depending on the humidity and dew point of the surrounding air, humectants can either draw in too much moisture, making hair excessively frizzy and ruffled, or draw away moisture from the hair strand, making hair dry and brittle.
What are examples of common humectants?
Humectants are commonplace in many products we use on a daily basis, including in haircare products. Common examples of humectants include:
- Glycerin
- Propylene glycol
- Sorbitol
- Hyaluronic acid
- Panthenol
- Polyethylene glycol (PEG)
- Keratin
Should I be considering a humectant as part of my haircare routine?
If you’re noticing that your hair feels excessively dry, a haircare product containing a humectant could be helpful. If you’re looking to add extra bounce to your curls, humectants in leave-in conditioners and similar products can help with that, too.
However, if you live in an environment where the air is either extremely dry or extremely moist, pay attention to how your hair responds to using any humectant. Excessively humid air can cause too much moisture to be drawn into your hair, particularly when your hair is highly porous, causing it to lose shape and create excess frizz. Dry air can draw moisture away from your hair strands as well, contributing to premature breakage and split ends.
