Alcohols have a really bad reputation among skincare enthusiasts. Although they show up in skincare formulations all the time (either as solvents, preservatives, to speed up drying times, etc.) many skincare aficionados prefer to avoid alcohols at all costs. We read our ingredient labels faithfully, and the moment we see the word “alcohol”, we roll our eyes and move on to the next product.
But the question is: why are alcohols so bad for our skin in the first place? And if they’re so awful, why do manufacturers use them?
The Science-y Bit: Defining Alcohols
What lots of people don’t realize is that “alcohols” encompass a range of chemicals, not all of which share the same properties. Chemically speaking, an alcohol is any organic compound in which a hydroxyl functional group (–OH) is bound to a saturated carbon atom. But these molecules can have very different properties depending on where that hydroxyl group shows up.
In other words, because of their different molecular arrangements, different alcohols look, feel, and behave differently.
For example? Glycerin is an alcohol. Glycerin, that wonderful humectant that binds water to our skin and is found in almost every beauty line ever invented? Yep, it’s an alcohol.
Ok, so then why the bad rap? Let’s break it down.
When most people talk about alcohols, they’re usually talking about a subgroup of alcohols called “simple alcohols”. You might see them listed on a label as:
- SD alcohol
- Denatured alcohol
- Isopropyl alcohol
When used in skincare, their purpose is often anti-bacterial, to reduce drying time, or as a solvent. The perceived problem with these alcohols is that, on their own, they can be quite drying.
More Sciency-y Bits: How Alcohol Dries the Skin
Simple alcohols are hygroscopic, meaning they easily bind to water. So when the alcohol molecules come into contact with the skin, they attract and bind to any nearby water molecules. That part’s fine. But at the same time, simple alcohols also have a low “heat of evaporation”, meaning they evaporate quickly (which can be highly desirable in skincare, as you rarely want to walk about with a wet face.)
The problem is that the alcohol binds with the water before it evaporates, and it takes the water with it when it goes. In this way, alcohol contributes to a process called transepidermal water loss, or TEWL. TEWL makes the skin uncomfortable, dry, itchy, and has the potential to damage the moisture barrier (which can lead to inflammation.)
Simple Alcohols in Skincare Manufacturing
Simple alcohols also have the ability to dissolve oils, another property that is very valuable in manufacturing skincare products. Recall that oils don’t dissolve in water, and most skincare products are water-based. So in order to get oily ingredients to dissolve in water and remain in solution, manufacturers will use alcohols to bind these otherwise antagonistic ingredients together.
But on the other hand, the potentially negative effect of alcohol’s ability to dissolve oil is that simple alcohols can reduce oil in the skin. That’s why you often see simple alcohol in drugstore formulations marketed to oily, acne-prone teenagers. While in the short term it can make skin less oily, in the long term this drying out of the skin can compromise the moisture barrier.
While it’s probably safe to say that most of us shouldn’t be putting straight simple alcohols on our faces, there are valid reasons to formulate products using simple alcohols, and their mere presence on a label does not mean you must eschew that product. How a product affects your skin is not just about individual ingredients but the formulation as a whole. Done properly, alcohols can exist with other ingredients to create an overall product that doesn’t feel drying at all.Alcohols in skin care have a bad rap that they probably don't deserve. Click To Tweet
As with anything, however, you know your skin best, and should follow your instincts and your history.
This second group of alcohols is derived from natural fats and oils. Some common fatty alcohols you’ll find in skincare include:
- Cetyl alcohol
- Stearyl alcohol
- Lauryl alcohol
- Oleyl alcohol
- Lanolin alcohol
The alcohols are often used in skincare because they are emollient, increase slip, or thicken the product. They are not at all drying and most people can use these ingredients without issue. In fact, many people would consider these ingredients to be an asset in their skincare products. However, it’s worth nothing that cetyl alcohols are derived from coconut, so those with coconut sensitivity may want to avoid. In addition, it may clog pores in some individuals.
And there you have it! (Almost) Everything you need to know about alcohol in skincare and cosmetics. Armed with an understanding of how alcohols work, how they vary, and how they’re used in your skincare products, you are well prepared to make smarter decisions for your face and your wallet.