Fancy skin care is a singular pleasure. Spreading a luxe peptide serum, for instance, on your regular-person face might be the highlight of your day—even when you’re not exactly sure what those fancy skin-care ingredients do.
As one of those fancy ingredients, peptides tend to be inexpensive products—even by high-end skin-care standards. So why do companies charge such a premium for peptide serums and creams? Are they really that good?
It’s complicated. On one hand, peptides are one of the few trendy ingredients that scientists and dermatologists agree can really do something to combat the signs of aging, like fine lines, wrinkles, and sagging skin. On the other, brands make lofty claims about their peptide-containing products that may or may not fully match up with what we know about them.
What is a peptide?
Peptides are molecules made up of relatively short chains of amino acids. Although they have a variety of uses in biochemical processes, they’re most often called the building blocks of proteins because, well, they’re what proteins are made of. If you think of a single protein molecule as a completed Lego Millennium Falcon, peptides are the individual blocks, while amino acids are the actual plastic.
In the context of skincare, proteins almost always refers to collagen, the protein that gives your skin its structure. As we get older, the collagen proteins in our skin break down, contributing to everything from wrinkles to a lack of elasticity. Most peptide-containing products aim to either increase the amount of collagen your cells produce or decrease the amount of it that gets broken down, with the ultimate goal being smoother, plumper, healthier skin.
What do peptides do?
All peptide products aim to deliver similar benefits but different peptides have different functions. “Basically, as we age, we’re hoping to keep our skin thick,” Mary L. Stevenson, M.D., assistant professor in the Ronald O. Perelman Department of Dermatology at NYU Langone Health, tells SELF. “To do this you need to clear away cellular debris and breakdown products [from collagen breakdown], and stimulate the production of more collagen.” Peptides can do both of those jobs, but individual peptides may do this in different ways.
Peptides in ingredient lists
So the specific way a product works depends on the individual peptides it contains. But figuring out which peptides a product contains can be confusing. Some products with peptide right in the name don’t list specific peptides in the ingredients—like this extremely expensive Tata Harper cream, which contains “hydrolyzed avocado protein,” but nothing else even remotely peptide-adjacent. Other products that do contain peptides may list them simply as peptides or oligopeptides, often followed by a number. (By the way, the prefix oligo- literally means “few” and usually refers to peptides with 20 amino acids or fewer—which covers pretty much every peptide used in cosmetics.)
Types of peptides
You don’t need to memorize the names of every peptide you might see on an ingredients list, but knowing roughly which kinds are out there can be very helpful when choosing a product. Most literature reviews of the function and efficacy of cosmetic peptides recognize five different categories, based on how they’re proposed to work.