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If you have a skin care routine, you’ve probably noticed that peptides are in everything right now. Cleanser? Fancy formulations have peptides. Hyaluronic acid serum? Peptides present! Moisturizer, toner, exfoliator, face masks: check, check, check, and check. You can find peptides in products in all of these categories. They’ve even found their way into makeup; Hailey Bieber’s brand Rhode released a popular peptide-packed lip tint last year, and you can find them in mascara, eye shadow, blush … the list goes on.
Indeed, they’re “one of the skincare industry’s favorite ingredients right now,” Vogue reported in December. At a Clinique launch event in early 2024, a dermatologist declared peptides to be “the buzzword of the year.” The reign of peptides seems liable to continue: “Skincare is in its peptides era,” the beauty and fashion website Hypebae announced last month.
Some of the moment can be chalked up to, well, the moment. As in fashion, trends in skin care come and go. You could say that peptides are skin care’s low-rise jeans: They were both all the rage in the 2000s. Now they’re back. In a few years, the focus might shift to retinol, or niacinamide acid. “It’s all cyclical trends,” says Valerie George, a cosmetic chemist and co-host of the podcast The Beauty Brains.
Whether you’ve purchased peptides or not, you’ve definitely used them. Peptides, which are short chains of amino acids, exist naturally in the body and work as messengers within the cell. A peptide’s job is to tell your cell what to do: say, “synthesize collagen,” or “support skin repair.” These are things your skin does naturally, without the help of any fancy creams. But the peptides in skin care products are intended to enhance those natural processes—sort of like passing a note to the cell, where the note can say whatever you want. In theory, “you could pretty much create a peptide for anything,” says George. In medicine, peptides present powerful therapeutic opportunities: They’re studied in everything from cancer treatment to pain relief. You’ve surely heard of the most famous therapeutic peptide: synthetic insulin, used by people with diabetes.
In skin care, manufacturers promise peptides will do everything from boost collagen and elastin production to reduce wrinkles à la Botox (unsurprisingly, they’re big in the anti-aging space). Natural peptides can do those things. And we have the tools to ask artificial peptides to do those things: Recent advances in research have led to a better fundamental understanding of how peptides work, and how they can help in medical settings (which might also be contributing to their current moment in the skin care spotlight). “If you look at the laboratory science of peptides, if you look at the study of peptides within the cells of our body, they really do work,” says George. But are you going to notice a long-term difference by using a cream with peptides? “The truth is, I don’t think any of us know.” There are just too many factors: genetic; environmental; not to mention the effects of other ingredients in the product. Maybe your skin will look fab as you age—but will it be thanks to the peptides, or the retinol, or your genes, or something else?
Theoretically, the peptides in your cream could do something, agrees King. “But we don’t have a whole lot of data to see clinically that they’re doing this.” Unlike drugs to treat medical issues, skin care companies—whose products are technically classified as “cosmetics”—aren’t required to release trials showing that their products work. Dermatologists might recommend peptide products to patients, but they aren’t really prescribing peptide medications, says cosmetic dermatologist Hadley King, the way they might an acne treatment.
Aside from those complex factors like genes and environment, a peptide’s abilities hinge on a few things. First, its size. The bigger the peptide, the harder it is for the peptide to penetrate your skin. Its composition matters too: There are things that a chemist can add to a peptide to “trick” the skin into opening its doors to a peptide, regardless of its size, says George. Then there’s the concentration. For the peptide to work, there needs to be enough of it in the product.
It’s impossible for a consumer to know any of these details just by looking at a product’s label, George says. Many peptide formulations are proprietary and patented. And there’s no magical minimum percentage needed for a peptide to work; it varies by peptide (of which there are many kinds) and depends on too many different factors. “A layperson may look at a 0.5 percent label and say, Wow, that’s like putting a Kool-Aid packet into a swimming pool, and I’m being ripped off,” she says, when “in actuality that could be, for that peptide, an efficacious level.”
But some formulators intentionally put very little peptide in a product, says King, knowing that the buzzword is enough to attract customers. She saw this firsthand a couple of years ago while working with a brand launching a new product with a peptide. Impressed by the peptide on the ingredient list, she asked the team about what it promised to do—but they seemed disinterested in discussing it, she recalls. When she kept pushing, they finally told her that the peptide was just there for marketing purposes, and didn’t have a high enough concentration to do anything. “I was like, Oh,” she says. “That was very eye-opening.”
What’s a consumer to do? “It always goes back to trying to look at the science,” says King. Don’t bother much with the label (if the peptide is higher up in the list of ingredients, that’s usually a good sign, but it’s not a definite). Instead, look on a company’s website to see if they’ve conducted clinical trials, where they can tell you what effect their product had on a tested population. Many of these trials only follow the shorter-term effects of the peptides for a small group of people, but they can still be useful in making an educated guess at how a cream may or may not help your skin. Look for third-party sources that have investigated individual products, such as George’s podcast The Beauty Brains, where George and another cosmetic chemist look into a different product’s efficacy in each episode. Tools like the INCI List, a digital decoder for skin care products, can help consumers see through false claims, a medical aesthetician told Hypebae. In general, seek out skin care advice that is science-based; George recommends esthetician Renée Rouleau’s blog.
Also, follow the money—that is, the company’s money, not the money they’re charging you. Larger, more established companies have the resources to do more clinical testing of their products, says George. For instance, Estée Lauder and L’Oreal both have their own R&D branches. (Plus, Estée Lauder’s line focuses on nighttime skin care, and peptides are thought to absorb better at night, so George thinks their products hold promise.) On the flip side, when you’re looking at product cost, “expensive” doesn’t necessarily mean “better.” Peptides often have reasonable price tags, says King, so a high price can simply reflect marketing costs. Both King and George recommended the Ordinary’s peptide serum as a good budget-friendly option.
But at the end of the day, while it might be fun to try them out, George says she wouldn’t spend more money on a moisturizer just because it has a peptide in it. The funny thing is that while we quibble about these products that may or may not work, there’s one tried-and-true product that guarantees good skin: sunscreen, whose only sin is not being sexy enough. “That is going to do way more than anything else,” says King. “Focus on that first.”
