It's usually the most complicated, exotic, and otherworldly sounding ingredients that get us the most excited. Of course, we know rationally that a long name doesn't equate to results but our minds like to think they do. However, there's one hardworking sleeper ingredient that's here to prove us wrong and that's glycerin.
When we think of moisture boosters in skincare, we immediately think of hyaluronic acid, but you can consider glycerin its less glamorous but highly effective sister. It's probably already hiding out in some of the products you use too, so now is the time to get acquainted with it. To give you the full lowdown on what glycerin is, we spoke with cosmetic scientist Rachael Polowyj, MSc, of U.K. chemical company IMCD; Dr. Julia Tzu, founder and medical director of New York's Wall Street Dermatology; and New York-based dermatologist Dendy Engelman, MD, on how you can reap all of this ingredient's benefits.
GLYCERIN
TYPE OF INGREDIENT: Hydrator
MAIN BENEFITS: Moisturizes skin, smoothes skin, makes skin appear dewy.
WHO SHOULD USE IT: Generally, glycerin is safe for all skin types.
HOW OFTEN CAN YOU USE IT: Products with glycerin can be used topically multiple times a day.
WORKS WELL WITH: Other moisturizing ingredients, like rose water or hyaluronic acid.
DON'T USE WITH: There are no known interactions; however, high glycerin concentrations are rarely used in skincare products.
We know that your skincare dictionary is already bursting at the seams but trust us, this is one that you need to save and file.
"Glycerin works as a humectant, it attracts moisture from the air into the stratum corneum (top layer of skin), and due to its low molecular weight, will continue to draw moisture to the deeper layers of the dermis. It has a molecular weight of approximately 92 g/mol, which means it is able to penetrate deep into the skin," Polowyj explains.
According to Engelman, "Glycerin is a natural occurring compound in the body. In topical skincare, it is derived from plants," she says.
In other words, after you apply glycerin, the magic happens deep inside the skin. Once it's absorbed, it can get to where it's needed, replenishing the moisture your skin loses.
There are no known side effects of glycerin when used as an ingredient in skincare products; however, it may cause an allergic reaction if used in high concentrations: "In general, glycerin is a super safe skincare product," says Tzu. "However, as with any product, allergic reactions or irritation are possible, albeit rare."
Almost everything can benefit from a healthy dose of glycerin, which means it can be added into almost every single step of your routine.
"Usually glycerin should already be premixed with a number of other ingredients that form the vehicle of a moisturizer or other moisturizing skincare product," says Tzu. "A cosmetic chemist is the professional who usually does the necessary work to create the perfect ratio of ingredients for a moisturizer. I would not do too much [in terms of] DIY chemistry projects by mixing glycerin with other compounds. This should be the work of a chemist. Just sit back, relax, and apply the moisturizer on mildly damp skin."
As Polowyj explains, "It's one of the most commonly used raw materials in the cosmetics and pharmaceutical industries and in chemistry, glycerin is the basic backbone of most essential lipids, which are oils found within your skin, so it has a great affinity to the skin." As a result, you'll see it as an ingredient in a lot of skincare products, especially in moisturizers, cleansers, and serums. It's an easy and quick-fire way to get super smooth and moisturized skin without needing a separate product.
When you're looking for key actives you'll want them to be nearer the top, but for glycerin, you might need to look a little further down. "It can be quite a sticky material, so you don’t want to see it too high up on the ingredients list as it will affect the way the product feels. Generally speaking, it’s ideal to see it around the third or fourth ingredient down, with a typical usage level of 10%," Polowyj explains.