Polynucleotide Injections (PDRN): The 'Salmon DNA' Skin Treatment

If you have scrolled through skincare content lately, you have almost certainly seen the phrase “salmon DNA” attached to a glowing before-and-after. It sounds more like a wellness fad than a serious treatment — yet polynucleotide injections have quietly become the standout growth story in UK aesthetics, with an estimated 19,000 monthly UK searches and one report naming them the “breakout treatment of 2025”. So what are they actually doing under the skin, what can they realistically achieve, and how do they sit alongside more familiar options like fillers and Profhilo? Here is a clear, honest guide.

What are polynucleotide injections?

Polynucleotides — often abbreviated to PN, and closely related to the term PDRN (polydeoxyribonucleotide) — are purified DNA fragments most commonly derived from salmon or trout. That is where the “salmon DNA” nickname comes from. The fragments are highly refined and purified for cosmetic use, then injected into the skin in tiny amounts.

The crucial thing to understand is that polynucleotides are not a filler and not simply a hydrator. They behave as a regenerative signalling molecule — in other words, they prompt your skin to repair and renew itself rather than physically plumping it out. That distinction shapes everything about what they are good for and who they suit.

How they work beneath the skin

The science here is more established than the trendy nickname suggests. The core mechanism, documented in a 2017 systematic review, is that PDRN activates adenosine A2A receptors on your fibroblasts — the cells responsible for making collagen. Switching on those receptors sets off a helpful cascade: increased release of VEGF (vascular endothelial growth factor), which encourages the formation of tiny new blood vessels, alongside stimulation of type I collagen synthesis in tired or damaged tissue.

On top of that, polynucleotides have anti-inflammatory properties and support general tissue repair. This is why they are so often chosen for thin, fragile or sun-damaged skin — such as the delicate under-eye area — and why practitioners sometimes use them to help skin recover after laser treatments.

Unlike a filler that works the moment it is placed, polynucleotides ask your own cells to do the rebuilding — so the improvement is regenerative and gradual, not instant.

An honest word on the evidence

It is worth being straight about the research. The underlying pharmacology is robust and well documented. However, the aesthetic-specific clinical trials — the studies looking directly at fine lines, under-eye rejuvenation and skin elasticity — are still a developing area, candidly described by commentators in the field as mostly small, mostly split-face and mostly open-label rather than large blinded trials. The biology is sound; the depth of high-quality trial data specific to facial outcomes is simply still smaller than for long-established treatments, and is expected to grow as the category matures. That is not a reason to dismiss polynucleotides — it is a reason to have realistic expectations.

What can polynucleotides treat?

Because they improve skin quality rather than adding volume, polynucleotides shine in areas where the skin itself is the problem:

• Under-eyes — one of the most popular uses, targeting thin, fragile, crepey skin and improving texture and the look of dark circles
• Full face — general improvements in skin quality, elasticity and radiance
• Neck — a notoriously hard-to-treat area that benefits from the collagen-stimulating, reparative action
• Hands — improving skin thickness on an often-neglected, prematurely-ageing area

Costs, protocol and how long results last

In the UK, polynucleotide treatments typically run £250–£600 per session, with a course of 2–3 sessions recommended for optimal results, usually spaced several weeks apart. Independent 2026 cost data puts a full course in the region of £400–£1,200. Because the effect is built gradually by your own cells, a single session is rarely the end of the story.

Results typically last 6–12 months — broadly comparable to Profhilo — reflecting the natural turnover of the freshly stimulated collagen and improved tissue quality. Many people choose periodic maintenance to sustain the benefit.

On safety, polynucleotides have a favourable profile. Reported side effects are generally limited to mild, short-lived swelling and bruising at the injection points, consistent with other superficial micro-injection techniques. No major safety signals appear in the current literature — though, as above, the overall depth of trial evidence remains smaller than for the most established categories.

Polynucleotides vs fillers vs Profhilo

These three are frequently confused because they are all injectables, but they do genuinely different jobs. The table below sets them side by side.

The simplest way to think about it: if you have lost structural volume and want contour restored, filler is the tool. If your concern is skin quality — laxity, dullness, hydration — then a bio-remodelling approach such as Profhilo or a regenerative one such as polynucleotides is more appropriate. We cover the hydration-focused options in our guide to Profhilo and skin boosters, and the structural side in our guide to dermal fillers for facial rejuvenation.

A quick note on the brands you may hear named: Plinest, Nucleofill, Plenhyage and NITHYA are among the polynucleotide products used in UK clinics, while Rejuran is the well-known Korean, salmon-derived category leader referenced internationally. Different formulations suit different tissues — finer skin under the eye versus denser areas.

Where polynucleotides sit in a wider plan

Polynucleotides are a skin-quality treatment, not a lifting one. They can make thin, tired skin healthier and more resilient, but they will not tighten a softening jawline or lift sagging tissue — that is a job for treatments that build deeper structural support. If your goal is genuine firming and lift, energy-based options are usually more relevant: our clinic focuses on non-surgical tightening such as HIFU, which reaches the deep support layer of the face, and radiofrequency skin tightening, which heats the skin to stimulate collagen and firmness over time.

Many people get the most natural result by pairing approaches — for example, improving skin quality with a regenerative or resurfacing treatment while addressing laxity separately. If texture and fine lines are on your list, our overview of microneedling for facial rejuvenation is a useful companion read, as it works on skin quality through a different, collagen-stimulating route.

Is a polynucleotide treatment right for you?

Polynucleotides are a genuinely interesting, regenerative addition to the skin-quality toolkit — particularly for thin, fragile or under-eye skin where gentler, repair-focused options are limited. What they ask of you is patience and realistic expectations: a course of sessions, a gradual build, and an understanding that they improve skin rather than lift or volumise it. No treatment can guarantee a specific outcome.

The best next step is a proper conversation. Book a consultation with our team to have your skin assessed and your goals discussed honestly — including whether a skin-quality approach, a firming option such as HIFU or radiofrequency, or a combination will genuinely suit you. We would love to help you feel like a fresher, healthier version of yourself.