Peptides are everywhere right now. They're in your serum, your moisturizer, all over your feed, and probably somewhere in the skincare advice your most ingredient-obsessed friend sent you last week. But "contains peptides" doesn't really tell you much. There are different types of peptides in skincare, and they don't all show up to do the same job.
Think of peptides as short chains of amino acids, the building blocks that make up proteins in the skin. [1] In skincare, they're commonly grouped into four families based on how they function: signal, carrier, neurotransmitter-inhibitor, and enzyme-inhibitor peptides. [2] Knowing the difference makes an ingredient list a lot easier to decode… and helps you figure out which peptide you're actually looking for.
What's the difference between a signal peptide and a carrier peptide?
Think messenger versus courier: signal peptides send a message to your skin's own processes, while a carrier brings a partner ingredient along with it, most often copper. [3]
Copper peptides are probably the best-known carrier peptides. The other two families are named for what they interrupt: neurotransmitter-inhibitor peptides are made to interrupt a nerve signal, while enzyme-inhibitor peptides are made to slow specific enzymes. [4]
Signal peptides are formulated with firmer, smoother-looking skin in mind [4], a look that comes from the skin's own proteins, like collagen and elastin.
Keep in mind that peptides aren't the same thing as growth factors (even though they're often discussed together in skincare). Peptides are short chains of amino acids, while growth factors are larger proteins that act as signaling molecules in the skin. [1]
Which peptide is right for your main skin concern?
Start with what you see in the mirror. If expression lines are your main concern, look for neurotransmitter-inhibitor peptides, which are designed to interfere with signals involved in repeated facial movement. [4] If you're focused on skin that looks less firm or smooth, signal peptides are formulated with those exact concerns in mind. [4] Carrier peptides, including copper peptides, are commonly used in formulas focused on skin renewal and firmness, while enzyme-inhibitor peptides may help support aging skin by slowing the activity of specific enzymes. [2, 3]
What does a peptide moisturizer do, and how is it different from a peptide serum?
A peptide moisturizer combines hydration and peptides in one step [5], while a peptide serum is typically a lighter, more concentrated layer designed to go on before your moisturizer. So when you're fine-tuning your own skincare routine, the choice often comes down to whether you want to do one step or two.
Why the base matters. Many peptides are relatively large, water-loving molecules. The top layer of your skin, the stratum corneum, is oily and built to keep water-loving things out. [4, 6] (Naturally, they don't get along.) Size is one part of what gets past that barrier. [7, 8] The formula carrying the peptide and your own skin? They can influence that, too. [9] That's why the base matters as much as the peptide itself. A moisturizer pulls double duty: it hydrates and smooths while delivering the peptide in the same step. [5] A serum keeps things lighter, making it easy to layer under the rest of your routine.
One step or two. If you want the hydration and peptides in one step, that'll be the moisturizer. In a layered routine, apply your serum to bare skin first, let it sink in, then follow with moisturizer and SPF. Think thinnest to thickest. If your skin runs dry or you love a routine with a little ceremony in it, layer a peptide serum under a peptide moisturizer. There's no rule against wanting both.
Cream, gel or oil: what should you check in a peptide formula before buying?
Check four things: that the peptide is named on the ingredient list, what else is in the formula with it, whether the texture actually works for your skin, and whether it's something you'll actually use consistently. The formula you'll wear beats the one you'll admire in the drawer.
The label, in one glance. On an ingredient list, many peptides are easy to spot because "peptide" appears right in the name. Tripeptide-1 and Hexapeptide-9, for example, read exactly like that. [10]
The company it keeps. Look beyond the peptide itself. A well-rounded moisturizer may pair it with three types of ingredients that support hydration: humectants, emollients, and occlusives. [11]
Humectants pull water in and hold onto it. Think glycerin, hyaluronic acid, and panthenol, all ingredients you'll find in YISE formulas. Emollients soften and smooth by filling the spaces between skin cells. Think ceramides and plant butters. Occlusives are the seal, the layer that shuts the door on water leaving your skin. They're especially useful as the final step in a nighttime routine. Pair peptides with ingredients that hydrate, soften, and help seal in moisture, and the formula can do more for your skin than a peptide could on its own. [11, 12]
Cream, gel or oil, by purpose. A gel feels cool going on, dries fast, and disappears into the skin, making it an easy pick for humid weather or skin that runs oily. [12] A cream feels richer and gives you more of that sealing layer, making it a natural fit for dry skin or a dry season, morning or night. [11, 12] An oil is the softening, sealing layer with no water of its own, so save it for last to help lock in all the hydration underneath. The "right" texture isn't set in stone. It can change with the season, because your skin does, too.
Before it joins your routine. Before committing, patch test the formula on a small area of skin and watch for redness, swelling, stinging, or other signs of irritation. If your skin reacts? Stop using it. When it passes the patch test, bring it into your routine on its own. One new product at a time makes it easier to know what caused a reaction (or the upgrade you were looking for).
Find Your Peptide Fit
There's more to a formula than any one ingredient. Peptide research can tell us about the ingredient itself, but not exactly how a finished formula will feel or perform on your skin. That's where the full formula shines.
Xtreme Glow Dewy Peptide Plumping Serum: the thin first layer that leaves skin instantly blurred, hydrated, and radiant.
Xtremely Quenched Peptide Instant Glow Moisturizer: the rich, hydrating layer that leaves behind a glassy, light-reflective sheen and a smooth base for makeup.
Meet Xtreme Glow Dewy Peptide Plumping Serum
Who it's for: Anyone dealing with dehydrated, dull-looking skin.
It's made with Tripeptide-1 and Hexapeptide-9, YISE's signal peptide pair, alongside Diglucosyl Gallic Acid. The lightweight formula goes onto bare skin as your first step. In clinical testing, measured skin hydration increased by more than 200% in just 15 minutes.
Skin feels soft, supple, and hydrated while looking instantly blurred and radiant. It's $68, and layers underneath the Xtremely Quenched Peptide Instant Glow Moisturizer when you're using the two together.
Meet Xtremely Quenched Peptide Instant Glow Moisturizer
Who it's for: Anyone with dry and dehydrated skin, daily makeup wearers fighting texture underneath, anyone layering two moisturizers to get both hydration and grip, or skin facing a dry climate or season.
This is YISE's peptide moisturizer, made with the same signal peptide pair: Tripeptide-1 and Hexapeptide-9. The formula pairs them with 4D Hyaluronic Acid, a blend of four molecular weights, plus a skin-identical ceramide, panthenol, glycerin, murumuru butter, and Centella Asiatica extract. After four weeks of use, measured skin hydration remained 57% above baseline, even when tested on cleansed skin.
The texture is luxurious and thick, yet it absorbs quickly and dries down before you layer. It feels rich and grippy on the skin, leaving behind a glassy, dewy sheen and a smooth base for makeup. If you've been stacking two moisturizers to get hydration and grip in the same morning, this is designed to give you both in one step. It's $68.
Step 1: After your serum, apply the moisturizer to your face and neck, morning and night.
Step 2: Let it dry down before layering anything over it.
Step 3: Follow with SPF in the morning, then makeup.
Pro Tip: Thinnest first. Press the Xtreme Glow Dewy Peptide Plumping Serum into bare skin and let it sink in before following with the moisturizer. Give the cream a minute to dry down before sunscreen, too, so your SPF applies evenly and your makeup has something to grip.
Common questions
What are peptides used for?
In skincare, peptides are used in serums, moisturizers, and other formulas to target concerns like the look of fine lines, firmness, and texture, depending on the type of peptide. [13] Peptides also have uses far beyond skincare, though, which is why you'll see the term outside the beauty aisle. [14]
Are peptides legal?
Yes, peptides can legally be used in skincare products in the U.S. Cosmetics and most cosmetic ingredients don't require FDA approval before going to market, but products still have to comply with federal safety and labeling requirements. [15, 16]
Are peptides good for you?
Peptides used in skincare are generally considered safe when formulated for cosmetic use, and a group of skin-conditioning peptides has been assessed and found safe as used. [17] That's different from peptides you might ingest or use for other purposes. In this case, we're talking specifically about topical skincare.
Are peptides natural?
Some are. Peptides occur naturally in the body, while many peptides used in skincare are synthesized in a lab to create a specific amino acid sequence. [1, 18] Neither origin automatically makes a peptide better; the amino acid sequence is what determines how it functions.
Are peptides proteins?
No, though they're cousins. Peptides and proteins are both made from amino acids, but peptides are generally shorter chains, while proteins are larger and fold into more complex structures. [1] Collagen is a protein; the peptides in your serum are the short chains.
