Polynucleotides: How They Work, the Evidence, and Who They Suit

There is a moment in the biology of polynucleotides worth stopping on. You take short fragments of purified DNA, place them in the skin, and the skin's own repair cells read them as a reason to get back to work, rebuilding the scaffolding they had stopped maintaining. It is one of the more elegant ideas in regenerative aesthetics: not filling the skin, not freezing it, but switching its own machinery back on.

That is also why it matters for the particular problem you may be recognising. Skin ages in two different ways. It can lose its shape, the volume going out of a cheek or a jaw. Or it can lose its quality, staying roughly where it was but turning thinner, drier and less resilient, so it stops catching the light and creams stop making any difference. Polynucleotides are built for the second kind, and used well they are one of the most interesting tools we have for it. Here is what they are, what the science actually shows, and whether they can give you back the skin you are picturing.

What polynucleotides are

They are chains of purified DNA, usually from salmon or trout, cleaned of the proteins that could provoke a reaction and cut to specific lengths. The length matters more than the source: it is what lets them behave as a signal the skin recognises rather than as inert material. Injected into the dermis, they are never read as genetic instructions. They are read as a prompt.

What that prompt does is threefold, and this is the part worth understanding. They bind and hold water in the tissue. They scavenge free radicals. And they wake fibroblasts, the cells that spin the collagen and elastin your skin is built from, coaxing them back towards the output of younger skin.

The free-radical part is the one I think is most underrated, so let me be precise about it. A great deal of skin ageing is oxidative: ultraviolet, pollution, smoking and time itself generate reactive oxygen species faster than the skin can neutralise them, while the skin's own antioxidant defences weaken with age (PMID 32799391). Polynucleotide chains act as scavengers of those radicals, and their breakdown metabolites appear to extend that protection; in the laboratory they shield fibroblasts from UVB damage (PMID 25473210). That is mechanism, shown in cells rather than proven as an outcome in a living face, but it is a sound and specific reason the treatment does what it does: it is not only feeding the skin, it is lowering the oxidative load that wears it down in the first place.

What the science shows

The evidence has matured enough to be worth reading closely. Pooled across the studies, polynucleotides improve skin texture, elasticity and hydration with a strong safety profile (2025 systematic review, PMID 39645667). A randomised controlled trial found they reduced skin roughness and wrinkle depth and improved both elasticity and collagen (PMID 25473210). For a treatment that works by signalling rather than filling, that is a genuinely strong result.

It is also a young field, and I read it as one. The trials are still modest in size, protocols are not yet standardised, and where polynucleotides have been compared directly with a hyaluronic-acid skin booster the two improved skin quality by comparable margins, each by its own route. I take that as the current edge of the evidence, not a ceiling. The mechanism is distinctive, the safety is excellent, and the science is moving quickly, which is exactly why we follow it as closely as we do.

Who they suit

They suit skin that has grown thin, crepey or slack in quality rather than shape: a face that has lost its bounce, a crepey neck, the ageing back of the hand. Because they work broadly on skin quality, they also layer well with the treatments that do the things they do not, volume and lift.

What they will not do is add volume, lift a sagging contour or fill a hollow, and I will tell you when that is the real problem, because the wrong treatment is the fastest route to disappointment. Where they fit, the change is the kind you notice slowly and then take for granted: skin that behaves like your own skin again, resilient and alive, rather than something you are managing.

What a course looks like

Polynucleotides are a short course, not a single visit. At Baudelaire that means three sessions of Nucleofill four weeks apart to begin with, because the effect builds with the skin's own repair cycle rather than appearing on the day. Because polynucleotides improve living tissue rather than sitting in it, the result is something you maintain rather than something that runs out. The improvement holds for several months, three to six in the studies, and from there a single session about every six months sustains it: two short visits a year to keep your own skin in better condition, not a look that fades. The injections use fine needles and are generally well tolerated; a small bruise or a little swelling at the points is the usual extent of it. The current price sits on the polynucleotides treatment page.

Around the eyes, specifically

The under-eye is where polynucleotides are asked for most, and it is also where treating the wrong thing shows the most, so it has its own detailed write-up: read polynucleotides for the under-eyes for what they do and do not do about dark circles, hollows and tired under-eye skin. And for what a realistic result looks like, two polynucleotides before-and-afters, read honestly sets out a real under-eye and a real face result, and how to judge one.

Polynucleotides or Profhilo

Not a rivalry, and often not a choice. Both improve skin quality by different mechanisms, polynucleotides by signalling repair, Profhilo by saturating the tissue with hyaluronic acid, which is precisely why they are often layered rather than picked between. Which of them, or both, and in what order, is a decision I take apart in full in Profhilo versus polynucleotides, and one that rewards knowing the materials well. Our Profhilo treatment page and skin boosters page compare them, and the polynucleotides treatment page is where to book.

The shift they represent

Here is my opinion, and it rests on a real distinction rather than a mood. The established injectables work by addition or subtraction. A filler supplies a volume the face has lost; a toxin subtracts the muscle movement that folds the skin. Both are elegant, both have their place, and neither changes the biology of the tissue itself. They act on the face, and the skin is left as it was. Done heavily, that is also how people end up looking done.

Polynucleotides work at the level the literature calls bio-stimulation and regeneration: instead of supplying material ready-made, they prompt the dermal fibroblast's own anabolic function, its synthesis of collagen and extracellular matrix, and they improve the environment those cells work in, the hydration and the oxidative balance (PMID 25473210). The target is not the appearance of ageing but several of its actual drivers: fibroblast output, the matrix that holds the skin together, and the oxidative load that degrades both. That is a genuine change in what an aesthetic treatment is even aimed at, and I am convinced it is where the serious end of the field is heading. I would rather be early to that than expert in the old thing.

None of it is dramatic, and that is the sophistication of it. You are not buying a new face or a recovery. You are giving your own cells a reason to do more of what they have quietly stopped doing, and letting what returns be unmistakably yours.

If that is the skin you recognise, a consultation is where we work out whether polynucleotides are your starting point or whether the real problem is shape, and treat it accordingly.

Part of my job is knowing which of these tools will still make sense in ten years. Polynucleotides are one of them. If your skin has lost its quality rather than its shape, they are where I would start.