Peptides are one of the most talked-about ingredients in skincare and aesthetics, and for good reason. They sit behind some of the most effective anti-ageing and skin-rejuvenating treatments available today. But the term gets thrown around loosely, on serum bottles, in clinic brochures, across social media, often without anyone explaining what peptides actually are or how they work.
This guide breaks it down properly: what peptides are, the different types and what each does, how they work inside the skin, why copper peptides are singled out as special, the difference between peptide creams and professional treatments, and how the most effective treatments deliver them where they actually matter.
What Are Peptides?
Peptides are short chains of amino acids. Amino acids are the building blocks of proteins, and when a small number of them link together, they form a peptide. When many link together in long, complex chains, they form proteins, including collagen and elastin, the two proteins most responsible for keeping skin firm, smooth and youthful.
Think of it this way: amino acids are individual bricks, peptides are small sections of pre-built wall, and proteins are the finished building. Peptides are large enough to do meaningful work, but small enough to be biologically active and to signal to your skin cells.
That signalling ability is the whole point. Peptides don't just sit passively on the skin, they communicate with it. They act as messengers that instruct skin cells to behave in specific ways, and that is what separates them from many other skincare ingredients that simply hydrate or exfoliate.
The Science: Peptides, Collagen and Skin Ageing
To understand why peptides matter, you need to understand collagen.
Collagen is the most abundant protein in the body and the main structural component of your skin. It forms a scaffold that keeps skin firm, plump and resilient. Elastin, another key protein, gives skin its ability to stretch and bounce back. Together they're responsible for the qualities we associate with youthful skin.
The problem is that collagen production declines with age. From our mid-twenties onward, the body produces progressively less collagen each year. On top of that natural decline, external factors accelerate the breakdown of the collagen we already have. Sun exposure (specifically UV radiation), pollution, smoking, poor diet and chronic stress all degrade collagen and elastin over time.
The visible result is the familiar signs of ageing: fine lines, wrinkles, loss of firmness, sagging, thinning skin, enlarged pores and a duller, less even complexion.
This is the gap peptides are designed to address. Rather than masking these signs, peptides work at the level of the underlying cause, the decline and breakdown of structural proteins.
How Do Peptides Work in the Skin?
Peptides work primarily by acting as biological messengers.
When certain peptides are delivered into the skin, they signal to skin cells, particularly fibroblasts, the cells responsible for producing collagen, that structural protein has been broken down and needs replacing. This effectively tricks the skin into ramping up its own collagen and elastin production, kickstarting the natural repair and renewal process.
In simple terms: a peptide arrives, mimics the signal the body sends when collagen breaks down, and the skin responds by building more. It's a way of prompting the skin to do what it did more readily when it was younger.
Because peptides work with the skin's own biology rather than forcing an artificial change, the results tend to look natural and develop progressively. This is also why consistency and proper delivery matter so much, which we'll come to.
The Different Types of Peptides
Not all peptides do the same job. Understanding the main categories helps explain why different treatments and products produce different results.
Signal peptides are the most common in anti-ageing treatments. They tell the skin to produce more collagen, elastin and other structural proteins. By prompting fibroblasts into action, they help restore firmness and reduce the appearance of lines over time.
Carrier peptides deliver trace elements into the skin, most notably copper. These trace elements are essential for wound healing and for the enzymes involved in building healthy tissue. Copper peptides are the best-known example and are covered in detail below.
Enzyme-inhibiting peptides work defensively. Rather than building new collagen, they slow down the natural enzymes that break collagen down. By preserving the collagen you already have, they help maintain firmness and slow the ageing process.
Neurotransmitter-inhibiting peptides work to relax muscle contractions in the skin, softening the appearance of expression lines and wrinkles. They're sometimes described as offering a very mild, topical effect loosely comparable in concept to anti-wrinkle injections, though far gentler and far less dramatic.
A well-designed treatment often combines more than one type of peptide, so the skin is being prompted to build new collagen, protected from breaking down what it has, and supported in the repair process all at once.
Why Are Copper Peptides Special?
Copper peptides deserve their own section, because they're among the most studied and effective peptides in skincare and aesthetics.
A copper peptide is a small protein fragment bound to a copper ion. Copper is a trace element the body needs for a range of biological functions, and when delivered into the skin via a peptide carrier, it becomes a powerful tool for repair and regeneration.
Copper peptides are valued for several reasons:
They support the skin's natural wound-healing response, which is central to regenerating healthier, stronger tissue. They help stimulate collagen and elastin production, improving firmness and elasticity. They have antioxidant properties, helping to protect the skin from the environmental damage that drives premature ageing. They support the skin's overall structure and tone, contributing to a smoother, more refined and more even complexion. And they help promote a healthy environment for skin renewal at a cellular level.
In short, copper peptides don't just signal for repair, they actively support the machinery the skin uses to carry that repair out. This dual action, signalling and structural support, is what makes them stand out from many other peptides, and why they appear in some of the most advanced regenerative treatments.
Do Peptides Actually Work?
It's a fair question, given how heavily peptides are marketed.
The honest answer is yes, peptides work, but with two important caveats: the type and quality of the peptide matters, and how it's delivered matters enormously.
A peptide can only do its job if it reaches the living layers of the skin where collagen is produced. This brings us to the single most important practical point about peptides, and the one most often glossed over in skincare marketing.
Peptides in Skincare vs Peptides in Professional Treatments
Topical peptide creams and serums can deliver genuine benefits, and there's a place for them in a good skincare routine. But they face a fundamental challenge: the skin is designed to keep things out.
The outermost layer, the stratum corneum, is a protective barrier. Its entire job is to stop foreign substances from getting in. Many peptide molecules are simply too large or unstable to penetrate deep enough through this barrier to reach the fibroblasts in the deeper layers of the skin where collagen is produced. A peptide that stays on the surface can't signal the cells that matter.
This is why professional treatments that deliver peptides below the surface tend to produce more dramatic, reliable and longer-lasting results. By bypassing the skin barrier, in-clinic treatments place active peptides exactly where they can do their work, in the deeper layers of the skin where collagen and elastin are made.
It's the difference between leaving a letter on someone's doorstep and hand-delivering it to the right person inside the building. Both are "delivery," but only one reliably gets the message where it needs to go.
This principle, getting active peptides past the barrier and into the working layers of the skin, is behind some of the most effective regenerative facials available in London today, including Injectual's DNA Glowcode Facial.
How Injectual's DNA Glowcode Facial Uses Peptides
The DNA Glowcode Facial is one of Injectual's signature regenerative treatments, and peptides are central to how it works. It's designed to deliver active ingredients beneath the skin's barrier, where they can genuinely influence collagen production and skin quality, rather than sitting on the surface where their impact would be limited.
Two peptide-rich elements are at the heart of the treatment.
Copper peptides are included for their regenerative, wound-healing and collagen-stimulating properties. As covered above, they don't just signal for repair, they support the skin's structural renewal and bring antioxidant protection, making them ideal for improving firmness, tone and overall skin health. Delivered into the skin rather than left on top of it, they can work the way the science says they should.
Jalupro brings a powerful combination of peptides and amino acids alongside a high concentration of hyaluronic acid. Jalupro is specifically designed to improve overall skin health by stimulating the body's natural production of collagen and elastin. It acts as a dermal collagen booster, improving skin texture, adding plumpness, and softening fine lines and wrinkles, while the hyaluronic acid delivers deep, lasting hydration where the skin needs it most.
By combining copper peptides with the peptide and amino acid complex in Jalupro, the DNA Glowcode Facial works on multiple fronts at once: stimulating new collagen, supporting the skin's repair processes, delivering intense hydration, and refining texture and tone. It's a treatment built around the science of how peptides actually work, rather than the hope that a surface product will somehow find its way in, and it's performed by qualified medical professionals.
Who Are Peptide Treatments For?
Peptide-based treatments are suitable for a wide range of people and concerns. They're particularly worth considering if you:
Are noticing early signs of ageing such as fine lines and loss of firmness. Have skin that looks dull, tired or lacklustre. Want to improve overall skin quality, texture and tone rather than chase a single quick fix. Are interested in a regenerative approach that works with your skin's own biology rather than against it. Want to support and prolong the results of other treatments, or build a long-term skin-health routine.
Peptide treatments are generally well tolerated, but as with any aesthetic treatment, suitability depends on your skin, your goals and your medical history.
What to Expect From Peptide Treatments
Because peptides work by prompting your skin's own collagen production, results develop progressively rather than overnight. You may notice improved hydration and a fresher appearance fairly quickly, but the deeper benefits, improved firmness, texture and tone, build over the following weeks as new collagen forms.
For this reason, peptide-based treatments are usually most effective as a course rather than a one-off, with maintenance sessions to sustain results over time. A qualified practitioner will recommend a plan based on your skin and goals, and will often combine peptides with complementary regenerative treatments for a more comprehensive result.
A consultation is the best way to determine whether a peptide-led treatment is right for you, and how it might fit alongside other options.
The Bottom Line on Peptides
Peptides work because they speak the skin's own language. By signalling for collagen production, protecting existing collagen from breakdown, and, in the case of copper peptides, actively contributing to regeneration and repair, they target the root cause of skin ageing rather than masking it.
But the science only delivers when the peptides do. Delivered properly, below the skin barrier and into the layers where collagen is made, they're one of the most effective tools in modern aesthetic medicine. Left on the surface, their potential is limited.
If you'd like to see what peptides can do for your skin, Injectual's DNA Glowcode Facial combines copper peptides and Jalupro in a single regenerative treatment, delivered where it counts, performed by our medical team in London.
