The 4 Types of Skincare Peptides

Not all skincare peptides work the same way. Scientists have identified four main functional categories of topical peptides, each targeting a different mechanism of skin aging. Understanding these categories will help you read ingredient labels and choose products that address your specific skin concerns.

1. Signal Peptides

Signal peptides are the most common type in skincare. They work by sending chemical signals to fibroblasts (the cells responsible for producing collagen and elastin) to ramp up their production. The most famous signal peptide is Matrixyl (Palmitoyl Pentapeptide-4), which has been shown in studies to significantly increase collagen synthesis and reduce the depth of wrinkles. You may also see Palmitoyl Hexapeptide-12 and Tripeptide-10 Citrulline on ingredient labels.

2. Carrier Peptides

Carrier peptides act as delivery vehicles, transporting essential trace minerals deep into the skin. The most important example is GHK-Cu (Copper Tripeptide-1), which delivers copper ions into the dermis. Copper is a critical cofactor for the enzymes that build collagen and elastin, and it also has antioxidant and wound-healing properties. GHK-Cu is one of the most extensively researched peptides in cosmetic science.

3. Neurotransmitter-Inhibiting Peptides

These peptides are often called "Botox in a bottle" because they work by relaxing the facial muscles responsible for expression lines. They inhibit the release of acetylcholine — the neurotransmitter that signals muscles to contract — thereby softening dynamic wrinkles caused by repeated facial movements like squinting, frowning, or smiling. The most well-known example is Argireline (Acetyl Hexapeptide-8), commonly found in eye creams and forehead serums.

4. Enzyme-Inhibitor Peptides

The skin naturally produces enzymes called Matrix Metalloproteinases (MMPs) that break down collagen and other structural proteins. While this is a normal part of skin renewal, UV exposure and oxidative stress can cause MMP overproduction, leading to accelerated collagen degradation. Enzyme-inhibitor peptides work by blocking or slowing these destructive enzymes, helping the skin preserve its existing collagen. Examples include peptides derived from soybeans, silk proteins, and rice.