Peptides are chains of amino acids linked together by peptide bonds, and amino acids are the building blocks of proteins. Proteins like collagen, elastin, and keratin exist in our skin, hair, and nails—and thus caring for them should be a top priority for a well-rounded beauty routine. Peptides are naturally present in the body, and there are many kinds that all have their own unique properties and functions.
When used topically, they act as messengers for the skin, says board-certified dermatologist Hadley King, M.D.: “Neuropeptides act as chemical messengers. In the skin they can be synthesized by keratinocytes or endothelial cells [which will, in turn, strengthen the epidermis, or skin barrier], or they can be released into the skin from nerve endings. They can act by modulating the release of neurotransmitters,” she says.
Put simply, “When you apply it topically like in a serum or moisturizer you are telling your skin to create more collagen,” says New York City–based esthetician Taylor Worden.
And as Nava Greenfield, M.D., board-certified dermatologist at Schweiger Dermatology Group in New York City, notes, their use so far is indeed promising—even if she acknowledges there’s still more to learn.
“In the cosmeceutical space, we have little to work with in terms of products that can truly provide even minimal benefit in reversing some signs of aging, protection from collagen and elastin breakdown, and even encouraging collagen and elastin buildup,” she says. “Ingredients developed small enough to penetrate the skin yet strong enough to be effective at skin rejuvenation are exciting, and peptides have demonstrated potential as a possible ingredient to help the skin in exactly that way!”