Peptides, Explained: How a Skin Care Supercharger Became Beauty’s Big

These days, skin care savvy is at an all-time high, with some active ingredients—and what they do—becoming so well known that they’ve become part of the collective consciousness. (One such example: hyaluronic acid and its oft-cited ability to hold up to 1,000 times its weight in water.)

Peptides, however, are among the few ingredients that have achieved buzzword status in skin care formulations while remaining largely a mystery in terms of what, exactly, they do. Without understanding how they function in skin, it can be difficult to determine what they can in turn offer in one’s routine. The truth is that peptides are more versatile, potent, and valuable than many might think.

First, a brief biology refresher on amino acids, the fundamental building blocks within the body. A small chain of amino acids forms a peptide; a chain of peptides, meanwhile, creates a protein. “Peptides often act as little biological messengers, carrying information from one cell to another,” says dermatologic surgeon Antony Nakhla, DO. “The function that a specific peptide carries out is dependent on the types of amino acids involved in the chain and their sequence, as well as the specific shape of the peptide.”

Operating as go-betweens among the various cells within our skin and bodies at large, “peptides work to allow other cells to do their job better,” says dermatologist Sheila Farhang, MD. They are like the worker bees of the body, toiling away to keep our various systems humming.

While they are found naturally within skin, “when applied topically, peptides can trigger skin cells to perform specific functions,” adds Nakhla. These include stimulating the production of collagen and elastin—two proteins that serve as skin’s scaffolding, keeping it smooth and taut—as well as encouraging hyaluronic acid synthesis and regulating pigmentation production. In other words, depending on the peptide in question, it may help to firm skin, boost hydration, or even out skin tone.

These days, product formulators can choose from an array of peptides. Consider, for example, palmitoyl pentapeptides. “These send signals to produce more collagen and elastin for skin firming,” explains cosmetic chemist Ginger King. A peptide called insulin-like growth factor, or EGF-1, encourages wound healing, whereas another—alternately called sh-polypeptide-1 or rh-polypeptide-1—is a “cell-signaling protein that stimulates fibroblast cell growth and proliferation, thus increasing the synthesis of collagen,” Nakhla says.

Such long-term action is what gives peptides an advantage over some of their better-known peers. While hyaluronic acid, for instance, temporarily draws in moisture and plumps skin, “peptides work on a cellular level,” says Farhang. Peptides also don’t come with the drawbacks of other, similarly powerful ingredients. “Some people simply cannot tolerate retinoids, so products that add a peptide to a [lower-level] retinoid—so as not to be as irritating—are good options,” she adds.

With that in mind, it’s important to find the peptide serum, moisturizer, or oil that targets your individual concerns. Here, a guide to 15 options that go above and beyond.