Peptides in Skincare: Science, Myths, and Innovations

Peptides in skincare have emerged as one of the most exciting and scientifically backed ingredients in recent years. These small but mighty molecules are now found in everything from serums to moisturizers, promising benefits like smoother skin, fewer wrinkles, and improved elasticity. 

Peptides are short chains of amino acids, which are the building blocks of proteins. In the context of skincare, peptides play a crucial role in maintaining and improving skin health. They act as messengers within the skin, signaling cells to perform specific functions such as producing collagen, elastin, or other proteins that keep the skin firm, smooth, and youthful.

To understand peptides better, it’s helpful to know that their size matters. Each amino acid typically weighs between 80–110 Daltons (a unit of molecular weight), meaning peptides made up of 5–6 amino acids are small enough to penetrate the skin’s outermost layer (the stratum corneum). This ability to penetrate is governed by the 500 Dalton Rule, which states that molecules smaller than 500 Daltons can pass through the skin barrier and interact with deeper layers.

The magic of peptides lies in their ability to mimic natural processes within the skin. These small but powerful molecules act as messengers, triggering specific responses depending on their type. Let’s explore the key categories of peptides and how they work to transform your skin.

Signal peptides are perhaps the most popular category of peptides in skincare today — and for good reason. As their name suggests, these peptides act as messengers, sending biochemical signals from cell to cell. Scientists have deciphered the “language” of these signals and designed peptides that mimic them, effectively communicating with skin cells to promote specific actions. Signal peptides in skincare have many distinct advantages and uses. 

Signal peptides are versatile and are commonly used in formulations for mature skin, inflamed or sensitive skin, pigmentation treatments, and dry or fatigued skin.

Examples of signal peptides in skincare: Matrixyl, Rigin, Carnosine, Melanostatine.

Meder products containing signal peptides: Arma-Lift active serum and mask, Myo-Fix active cream and mask, Arma-Neck cream, Body-Day deodorant, Lumino-Derm mask. 

Carrier peptides in skincare play a vital role in delivering trace elements like copper or manganese to skin cells, aiding repair and renewal.

Carrier peptides demonstrate how skincare science can harness trace elements to repair and protect the skin at a cellular level.

Examples of carrier peptides in skincare: Cu-GHK, Mn-GHK.

Often referred to as Botox-like peptides (though I personally dislike this term), neuro-modulating peptides are famous for reducing muscle contractions that lead to expression lines.

These peptides are ideal for those seeking a natural approach to softening expression lines without losing their ability to smile or frown.

Examples of neuromodulating peptides in skincare: Argireline, Leuphasyl, Syn-Ake, Munapsys, Vialox.

Enzyme-inhibiting peptides in skincare work by preventing the breakdown of collagen and elastin — key proteins that keep the skin firm and elastic.

By preserving collagen levels, enzyme-inhibiting peptides help combat sagging and restore a youthful appearance.

Examples of enzyme-inhibiting peptides in skincare: Soybean fibres, Rice fibres, Silk fibroins.

Meder products: Circa-Night cream, Arma-Bust cream. 

Skin-penetrating peptides in skincare are one of the newest discoveries in peptide science. These slightly larger molecules (containing 10–15 amino acids) have an unexpected ability to penetrate deeper into the skin — and they bring other ingredients along with them.

This breakthrough opens new possibilities for delivering active ingredients deeper into the skin without compromising its barrier function.

Examples of skin-penetrating peptides in skincare: SPACE, X50 Pure White.

Meder products: Lumino-Derm brightening cream.

Peptides on their own are generally well-tolerated and unlikely to irritate the skin. However, irritation can result from other ingredients in a product’s formulation or from using overly intense products alongside peptides. For those with sensitive or inflammatory skin conditions like perioral dermatitis (PD), anti-inflammatory peptides such as Calmosensine or Skinasensyl can be particularly beneficial.

While peptides are highly effective, they don’t deliver instant results. Like all biological processes, peptide-driven changes take time. 

For example:

• Improvements in hydration or skin comfort may be noticeable within days or weeks when using moisturizing formulations containing peptides.
• Visible changes in wrinkles or pigmentation may take several weeks of consistent use.

The efficacy of peptides in skincare depends on several factors:

1. Amino Acid Sequence: The order of amino acids determines how a peptide functions—for example, whether it stimulates collagen production or reduces inflammation.

2. Molecular Chirality: The 3D shape of a peptide molecule affects its interaction with skin cells.

3. Delivery Systems:Some peptides benefit from advanced delivery systems that enhance penetration and stability.

Interestingly, many skincare concerns—such as sensitivity, wrinkles, or dark spots—can now be addressed with targeted peptide formulations.

When shopping for peptide-based skincare products:

• Don’t expect peptides in skincare to appear at the top of an INCI list (ingredient list). They are highly effective at very low concentrations — often as little as 0.00001%. Claims like 10% peptide usually refer to a ready-made peptide solution rather than the dry substance itself.
• Look for names like Palmitoyl ...peptide in ingredient lists — this indicates that product contains peptide designed for best penetration into the skin
• Research specific peptides in skincare if possible; their names often indicate their structure but not their function (e.g., dipeptide = two amino acids; tripeptide = three).

Peptides are naturally bioavailable and don’t typically require penetration enhancers. However, certain ingredients can interfere with their efficacy:

• Avoid pH-modulating ingredients (e.g., hydroxy acids) or aggressive retinoids when using peptide-based products—they may destabilize peptide structures or block absorption.
• Film-forming agents like mineral oils or silicones can also hinder penetration.

For best results, use a cohesive one-brand skincare routine designed specifically for peptide compatibility.

Microproteins

Microproteins are an emerging area of research defined as proteins with fewer than 100 amino acids. While they hold incredible potential — particularly in medicine — they remain largely unexplored as peptides in skincare due to their larger size and complex nature.

Growth Factors

Growth factors like Epidermal Growth Factor (EGF) are technically peptides but much larger molecules (~7,000 Daltons). While they cannot penetrate deep into the skin, they interact with receptors on keratinocytes at the epidermal surface to trigger regeneration pathways indirectly and therefore may have potential uses as peptides in skincare. 

The potential for peptides in skincare is virtually limitless. With over 600 currently available for cosmetic use — and more being developed every year — peptides in skincare now address nearly every aesthetic concern imaginable while offering unparalleled safety and bioavailability. As molecular biology continues to advance, we can expect even more innovative applications for these remarkable molecules.

Peptides in skincare are truly remarkable in their versatility and effectiveness. Whether they’re signaling cells to boost collagen production, delivering essential trace elements for repair, calming muscle contractions naturally, or preserving collagen from enzymatic breakdown, each type of peptide brings something unique to skincare formulations.

The latest advancements in peptide science continue to push boundaries — offering safer, more targeted solutions for nearly every skincare concern imaginable. With consistent use of peptide-based products tailored to your needs, achieving healthier, more radiant skin is no longer just a dream — it’s science at work.

Remember that patience and consistency are key when using peptides in skincare — and always consult research-backed formulations for optimal results.