How polynucleotides work, and what the evidence shows

what they are.

Polynucleotides are purified fragments of DNA. The products used in UK clinics, including Plinest, are derived from salmon, purified until what remains is a chain of the building blocks of DNA, without the proteins that would cause a reaction. They are injected into the skin, or into the scalp, as a gel.

They are not a filler. They do not add volume, and nothing you see after a course of treatment is product sitting under the skin. Whatever change there is comes from how the skin responds to them.

how they are thought to work.

The proposed mechanism has two parts. In laboratory studies, polynucleotides act on a receptor on the surface of skin cells, the adenosine A2A receptor, which is involved in repair and in calming inflammation. They also appear to provide the cells that make collagen and elastin, the fibroblasts, with building blocks and a signal to produce more.

That mechanism is plausible and reasonably well described in the laboratory. It is a different thing from proof of what happens in a patient's face, which is what the clinical studies try to answer.

what the evidence shows.

A systematic review of randomised trials published in 2026 found 7 trials, with 183 participants in total, across skin rejuvenation, scar prevention and wound healing. Across them, polynucleotides improved the outcomes each trial measured. The most consistent effect was in wound healing, where treated wounds closed faster than controls. Four of the trials were on skin rejuvenation.

Under the eyes, a randomised split-face trial of 27 people compared polynucleotides on one side with an uncross-linked hyaluronic acid on the other, three sessions two weeks apart. Both sides improved in elasticity and skin tone, and the visual scores did not differ significantly between them. That matters: it suggests polynucleotides do something useful for under-eye skin, and it also suggests they are not dramatically better than a simpler alternative.

For acne scarring, Araco and Araco published a randomised trial against placebo in the Aesthetic Surgery Journal in 2021, reporting improvement in moderate to severe scars. For nasolabial folds, a randomised exploratory study by Araco and colleagues in the Journal of Cosmetic Dermatology in 2023 looked at polynucleotides combined with a cross-linked filler, which is a common way they are used in practice.

In 2026, Ziade and colleagues reported a prospective study of polynucleotide injections for under-eye lines, following patients for 6 months with a validated patient questionnaire. It used a different polynucleotide product from the one used here, so it tells us about the class rather than a brand.

what the evidence doesn't establish.

The studies are small. The largest randomised trials here have a few dozen participants; the systematic review found 183 people across seven trials. Follow-up is usually months, not years. Several studies are funded or supported by manufacturers. Different trials use different products, concentrations and injection schedules, so results can't simply be added together. And few compare polynucleotides with doing nothing at all.

None of that means the treatment doesn't work. A fair summary is that polynucleotides appear to improve skin quality, particularly thin, damaged or scarred skin, with a low rate of side effects, and that the size of the effect for any one person is uncertain. That is why they are described here as a course that builds and is reviewed as it goes, rather than as a single result.

what a course involves.

Most protocols, including the expert consensus on the purified products, use 3 sessions 3 to 4 weeks apart, then maintenance once or twice a year. Each session is a series of small injections into the skin, or into the scalp for hair. There is little to see after the first session. Most people notice a change from 2 to 3 weeks after starting, building over the course.

Small bumps at the injection points settle within a few hours. Under the eyes, mild swelling or bruising for a day is more likely, and a cannula reduces it.

who they don't suit.

Treatment is not suitable during pregnancy or breastfeeding, or where there is active infection at the site. A fish allergy is not necessarily a reason not to treat, as the product is highly purified, but it needs to be discussed. Polynucleotides do not add volume, so they are not the right treatment where the concern is a hollow or a fold rather than the quality of the skin itself.

the short version.

Polynucleotides are a reasonable treatment for skin that has become thin, crepey or damaged, and for the under-eye in particular. The mechanism is plausible, the trials are encouraging and small, and the effect is gradual. They are worth considering for the right skin, with realistic expectations of a gradual change.

Polynucleotides treatment page · Under-eye hollows · Skin quality