What Are Ceramides, and How Do They Work?

Ceramides are lipids (a type of fat molecule) that are found naturally in our skin; they're the body's built-in moisturizer. "They make up the majority of the stratum corneum—the top layer of your skin—and are responsible for holding the cells together," explains Tiffany Libby, MD, a dermatologist in New York City. In addition to acting as the glue that keeps the skin barrier intact, ceramides are moisturizing agents that make skin feel soft. "As we age, ceramide levels in our skin decrease, so by the time we're 30, almost 40 percent of our skin's ceramides are depleted; by the time we're 40, that number increases to 60 percent," explains Dr. Libby. But it's not all gloom and doom: Upping your intake of leafy greens and healthy oils (coconut and avocado) and incorporating ceramides into your skin-care routine will reinforce your skin's barrier.

What do ceramides do?

Ceramides create a protective shield that keeps environmental irritants like dirt and pollution out while keeping moisture in. "There are studies that show ceramide-containing products can help alleviate and prevent severe skin dryness in the long run," says Gloria Lu, a skin-care chemist in Pasadena, California, and cofounder of Chemist Confessions Inc. When the lipid barrier becomes compromised (age, pollution levels, and sun damage all play a part), your skin looks and feels dry, but more concerning is that it's also now prone to sensitivity, irritation, and conditions like eczema.

How do you use ceramides?

Topical ceramides mimic the lipids found in your skin, so they're more easily accepted or absorbed than other ingredients (plus, they don't have far to go since they're only needed on the top layer). "Ceramides aren't a finicky ingredient; they're great for all skin types—sensitive, dry, and oily—day or night," says Chemist Confessions Inc.'s other cofounder and skin-care chemist, Victoria Fu. A topical formula will sink right in, filling any cracks that have been left by ceramide depletion. You'll often see ceramides paired with humectants like hyaluronic acid and glycerin, for additional moisture, points out Lu. And they can be used on your entire body, face to legs; apply a ceramide-rich formula onto damp skin for best absorption, recommends Dr. Libby.

This article originally appeared in the November 2020 issue of Health Magazine. Click here to subscribe today!