In the last couple of months, as I've started writing about beauty and skincare, researching products, and interviewing dermatologists, I've noticed one word, in particular, popping up quite often: peptides. I had a general idea that they were good for the skin. I mean, they're found in a lot of highly recommended skincare products, from creams to serums. But I didn't fully understand what they were and why they're beneficial to skin health.
I knew it had something to do with chemistry, which made me feel a little intimidated. I honestly thought after high school I'd never have to deal with chemistry again. There's a reason I became a writer and editor versus a doctor or scientist. But I am a journalist, and part of being one is gaining a full understanding of the subject you're covering. So this is how I ended up getting a chemistry lesson 13 years after graduating high school. Here's what I learned about peptides.
Peptides are short chains of amino acids that serve as building blocks for proteins, like collagen, elastin, and keratin. "When applied topically to the skin, peptides act as little messengers, triggering skin cells to perform specific functions such as building collagen and elastin, reducing inflammation, and locking in skin hydration," explains Robyn Gmyrek, MD, a board-certified dermatologist at Park View Laser Dermatology. "What is so fascinating about peptides is that they are comprised of up to 50 amino acids, and if you mix and match them in different sequences, then you can create a variety of peptides, each of which might have a different biologic effect. Peptides are so valuable because they are formulated into small enough pieces that they can penetrate through the stratum corneum—the outermost layer of the skin. Once they are able to get to the cellular level, they can exert their activity. This is in contrast to complete (not fragmented) proteins like collagen, for example, which is too large to be absorbed through the skin."
Gmyrek says there are four main peptides in skincare:
Carrier peptides: These deliver trace minerals to the skin to boost collagen production.
Enzyme inhibitor peptides: These work to slow down the skin's natural breakdown of collagen and elastin.
Signal peptides: They send messages to different parts of the skin to promote the formation and production of collagen, elastin, and other proteins.
Neurotransmitter peptides: They block the release of chemicals that cause the muscle contraction of expression lines. "These are much weaker than but work in a similar way to botulinum toxins to weaken the movement of the facial muscles so that expression lines are both improved and prevented. The most common neurotransmitter peptide that I see incorporated into skincare products is called Argireline, which is the brand name for a particular peptide, acetyl hexapeptide," Gmyrek says.
They're good for all skin types, but you should keep your specific skincare needs in mind when looking at different product formulas. "Opt for a moisturizing formulation with hyaluronic acid, glycerine, or ceramide that is alcohol-free if you have dry skin," Gmyrek suggests. "I would recommend a serum or a lotion that is lighter if you have oily or acne-prone skin."
"I feel strongly that you should not be layering on different products unless they were formulated and studied by the company that way. Many of these ingredients are unstable and are altered and rendered inactive by other chemicals," Gmyrek says. "So, use as directed and do not layer other products with active ingredients on top. Moisturizers are generally fine to layer, but even they can dilute the first product by combining it. If you need more moisture, try to find a very moisturizing product that contains peptides instead of layering."
Another option is to use combination products. Liu says most peptides are commonly incorporated into serums and moisturizers. These products can contain peptides and other ingredients like antioxidants or retinoids. Gmyrek adds that the products are presumably evaluated by the manufacturers to ensure that the combination of active ingredients remains.
While they can have a variety of benefits, Gmyrek says that these are some common skin conditions that can be treated with peptides:
Skin aging: "Peptides can message fibroblasts, cells in the skin that produce collagen, to increase production of collagen," Gmyrek explains. "They can decrease the breakdown of collagen and elastin in the skin. They can weaken muscle contraction, smoothing dynamic wrinkles caused by strong facial expressions."
Dryness: Peptides increase hydration and improve the skin barrier, helping it lock in moisture. With a better skin barrier, there is more protection against bacteria, UV rays, pollution, and other toxins.
Acne: They are able to kill bacteria, which we know is helpful when it comes to acne.
Liu says it's usually recommended to use the peptide product once or twice daily, and she notes that potential irritation or dermatitis is rare but possible, so make sure you test first. If you experience any redness, irritation, or another reaction, stop using the product immediately. And overall, it's important to follow the instructions for the specific product.
You might want to check with your dermatologist before purchasing. "As peptides are more novel and their size impacts penetration, I recommend seeing your dermatologist and purchasing medical-/professional-grade products that have been studied clinically for efficacy," Liu advises.
And be wary of any skincare promises. "Honestly, it is very difficult to know what you are getting in these products. While peptides have the ability to do all of the different things I mentioned above, it does not mean that any product that contains a peptide or peptide complex will be actually be effective or biologically active," Gmyrek explains. "In addition, there is no percentage of peptide or pH of the product that you should look for to assure that the product is active, so the best you can do is look for a listing of peptide high up in the ingredient list to assure that the product contains it, and I recommend consulting the company websites for their data on effectiveness."
Since more research needs to be done on the effectiveness of different peptides in products, Gmyrek recommends choosing products that contain other active ingredients that have proven to be effective, such as antioxidants, alpha hydroxy acids, and retinoids.
Take a look at some recommendations from Gmyrek, Liu, and our editors below: