What are polynucleotides (PDRN) — and how they really regenerate skin from within

Where polynucleotides come from — and why fish

Let's start with the name, because it explains a lot on its own. Polynucleotides (labelled PDRN or PN) are long chains built from fragments of genetic material — the same "building blocks" that make up the DNA of every living cell. This isn't a chemical substance invented from scratch in a lab. It's a biological building material that the body recognises as its own.

They're sourced from fish material — most commonly salmon or trout milt — then purified into a fully biocompatible, safe form. The choice of fish isn't random or "natural marketing": this particular genetic material is similar enough to human DNA for skin to accept it readily, while being free of features that could trigger an unwanted reaction. Purity and origin matter here, and they largely determine the price and safety of the product.

What actually happens beneath the skin — four things at once

This is where the real difference lies between a polynucleotide and a standard moisturising product. A moisturising cosmetic delivers something ready-made to skin — usually water and substances that bind it. A polynucleotide does something different: it triggers processes that skin carries out itself. It's not a delivery, it's a prompt. And it prompts on several fronts at once — and it's this multi-directional action that sets it apart from tools working "in a single dimension".

• It wakes up fibroblasts — the collagen factories. Fibroblasts are cells that produce collagen and elastin, the scaffolding responsible for skin firmness and elasticity. With age, they work slower and lazier. Polynucleotides act like a "get to work" signal — reminding them how to produce the building material skin has started to lack. That's why the effect is structural, not superficial.
• They bind water — but from within. Yes, polynucleotides hydrate intensely. But not by "coating" the surface — they bind water deep within the skin, where a cream can't reach. This is structural hydration — more often felt as "skin finally full and rested" than as momentary comfort after applying an emulsion.
• They calm inflammation and oxidative stress. Polynucleotides have antioxidant and anti-inflammatory action — they protect cells from "rusting", meaning damage driven by sun, pollution and lifestyle. This soothing component is exactly why vascular, irritated and reactive skin tends to tolerate them well.
• They improve microcirculation. Better-perfused skin is better nourished and oxygenated skin — and so it regenerates itself faster. It's a quiet but important part of the whole picture: it creates better conditions for the rest of the process to work at all.

Together, these four mechanisms give you skin that's denser, better toned, more hydrated and more radiant — and none of these changes involve adding volume or changing your features. This isn't "a new face". It's a better version of the same skin, brought to a state where it can work more efficiently.

Polynucleotides, hyaluronic acid and mesotherapy — why they're not the same thing

Polynucleotides are most often confused with three other things: fillers, hyaluronic acid bioremodelling (like Profhilo), and classic mesotherapy. All of them "do something" to skin, so it's easy to lump them together. But the difference isn't a nuance — these are different categories of tools for different jobs, which is exactly why they often work together rather than against each other.

The simplest way to remember it: a filler adds volume, hyaluronic acid hydrates and remodels, mesotherapy nourishes, and a polynucleotide teaches skin to work on its own. So it doesn't make sense to ask "which one is best" — the right question is "what's actually wrong with my skin". Grey, thin, tired skin is polynucleotide territory. Lost volume or a sagging contour is a different story with different tools altogether.

Why one injection isn't enough — the logic of a series

This is where our manual analogy comes back — and finally makes sense. Since a polynucleotide doesn't deliver a ready-made effect but assigns skin a job to do, it's logical that this job takes time. Fibroblasts don't produce collagen on demand in five minutes. Skin rebuilds slowly, at its own pace — and each session reminds it of the task before it has a chance to forget.

That's why polynucleotides are a classic cumulative treatment. Hydration and a "fresher" look are often felt almost immediately — and these are exactly what throws people off, creating the illusion that "this is it". Meanwhile, the real regenerative effect is still building. Full results come from a series of treatments spread over time, not a single visit — and this is one of those cases where judging the result after the first session is simply misleading.

1. 01

   immediately

   noticeable hydration and a "fresher" look; small bumps at injection points fade within hours

2. 02

   first days

   any redness or minor bruising fades — skin starts working "in the background"

3. 03

   a few weeks

   first visible signs of regeneration: radiance, firmness, less tired-looking skin

4. 04

   after the full series

   the effect builds and usually lasts six months to a year — with maintenance sessions recommended

Importantly, once the series ends, skin doesn't suddenly "get worse". It simply returns to its natural ageing pace, and the level achieved is maintained with single sessions every few months to a year or so. This isn't skin becoming dependent on the treatment — it's maintaining a state you've already built.

What this means in practice — and what not to expect from polynucleotides

First, an honest look at what this treatment won't do — because that saves disappointment. Polynucleotides won't fill a deep fold, won't add volume to sunken cheeks, and won't lift a sagging contour. That's not their role. If the problem is facial geometry — lost support, tissue that has dropped — the right tools are fillers, volumetry or threads. Polynucleotides work on skin quality, not its shape.

Now, who this treatment really suits. It's for skin that's tired, grey, "lifeless"; thin, "paper-like", losing firmness; dehydrated, unable to regain comfort despite good skincare; reactive and vascular, in need of calming down. It also works well in the delicate eye area, where skin is thinnest — and as support for regeneration after treatments that "damage" the barrier, like laser or peels. Finally, it can be a conscious form of prevention — used before skin has a chance to wear down significantly.

And here's another misconception worth clearing up: that this is "a treatment for women". The regeneration mechanism is neutral to gender — what differs is mainly the starting point. For women, polynucleotides most often fit into a "skin quality" plan: radiance, firmness, work on the thin eye area, fresher skin without a "done" look. For men, the goal tends to be more restorative — skin burdened by sun, oxidative stress, daily shaving, and usually a lack of routine sun protection. Both are looking for the same thing: healthier, denser, less tired skin without a visible "change". Hence the growing number of men for whom this is simply a neutral tool for skin condition.

Finally, the most important thing, which no article can decide for you: whether this is the right treatment for you. "Tired skin" means dehydration for one person, loss of density for another, and for someone else, an actual volume problem that a polynucleotide won't touch. Whether it makes sense — and in which variant — is decided by looking at your specific skin during consultation, not by an article or an advert. Below, we've gathered treatments that circle the same goal: better skin quality and regeneration.