Signal, Carrier, or “Botox-Like”: How to Decode Peptide Skincare

Peptides are one of the most talked-about skincare ingredients right now, and the number of peptide-based products on the market keeps growing. When applied topically, these molecules can support hydration, skin barrier health, and repair processes. But what makes peptides especially attractive is their anti-ageing effect, promising smoother, firmer skin.

The catch is that different types work through different biochemical mechanisms, which is why ingredient lists can contain various peptide names.

Here are four major groups used in cosmetics and the most common examples for each, so you know what to look for when reading a label.

Signal Peptides

Signal peptides act as messengers in the skin. They “tell” skin cells (especially fibroblasts, which maintain and repair the skin) to produce more collagen, elastin, and other structural proteins in the dermal matrix. This results in improved skin firmness and resilience and a smoother appearance of wrinkles.

Examples of signal peptides include Palmitoyl Pentapeptide-4 (aka Matrixyl), Palmitoyl Hexapeptide-12, Palmitoyl Tripeptide-5, Palmitoyl Tripeptide-1, Acetyl Tetrapeptide-9, Acetyl Tetrapeptide-11, and Tetrapeptide-30.

Carrier Peptides

Carrier peptides act as delivery systems. They bind to microelements such as copper or manganese and help transport them into the skin, where these minerals support key biological processes involved in skin repair and collagen synthesis.

Examples include Copper Tripeptide-1, Manganese Tripeptide-1, and others.

Neurotransmitter-Inhibitor Peptides

These peptides are often described as “Botox-like” ingredients in skincare. They work by interfering with the release of acetylcholine, a neurotransmitter that triggers muscle contraction. Relaxing facial micro-movements helps soften the appearance of expression lines over time.

Examples include Acetyl Hexapeptide-3, Pentapeptide-18, Tripeptide-3, and others.

Enzyme-Inhibitor Peptides

Peptides from this group help slow down the breakdown of collagen and other structural proteins by reducing the activity of enzymes that degrade them. They also have antioxidant properties and help neutralise reactive oxygen species (ROS) generated by UV radiation, which can trigger oxidative stress in skin cells and accelerate photoageing.

Examples include soy, rice, and silk peptides.

How to Choose a Peptide Product

Understanding which type of peptide is present in your cream or serum helps determine how the product will interact with your skin, but the overall composition matters just as much. A product may contain effective forms of peptides but still perform poorly or trigger side effects if the rest of the formulation isn’t suitable for your skin or contains harsh or questionable ingredients.

A helpful tech shortcut is using a beauty ingredient scanner app such as OnSkin. You can access a specific product via a barcode scan, packaging photo, or name search and check its overall safety profile from a general health perspective, as well as learn what benefits it may target (such as hydration, antioxidant activity, barrier repair, skin regeneration, wrinkle smoothing, etc.) and whether it suits your skin type.

A personalized approach is crucial, as some ingredients may clog pores on oily skin, while others can irritate dry or sensitive skin. Taking a patch test is also recommended when introducing any new skincare products to exclude the risk of allergies or other individual adverse reactions.

How to Incorporate Peptides Into a Skincare Routine

Since peptides are anti-ageing ingredients, they are generally recommended for inclusion in beauty regimens starting around age 40 in facial product formulas. It’s best to prioritise products that remain on the skin for longer periods (think creams vs. masks), and use them consistently over time, so the active ingredients can work to their full potential and start generating visible results.

In the delicate around-the-eye area—where the skin is thinner and facial expressions are more active, making it prone to earlier fine lines—an eye cream with peptides can be introduced from around the age of 30 to 35.

Peptides are suitable for daily use as part of both morning and evening routines since they do not increase the skin’s sensitivity to the sun. However, peptides are pH-sensitive and don’t tolerate highly acidic environments, which is why they shouldn’t be combined with exfoliating acids such as AHAs or BHAs or with acidic forms of vitamin C, such as ascorbic acid.

While peptides can deliver meaningful anti-ageing benefits by supporting collagen production, they are not the most powerful anti-wrinkle ingredients available. For this reason, they are often recommended in combination with skin-rejuvenating ingredients such as retinol, bakuchiol, or non-acidic forms of vitamin C, which also help stimulate new collagen synthesis in the skin. These actives complement each other and can help achieve more sustainable and long-term results.