Polynucleotides
Doctor-Led treatments in Hale, Altrincham & Cheshire
Regenerating the skin itself, not filling it
If your skin has started to look thinner, less firm and more tired, and the skin beneath your eyes has gone crepey in a way that make-up only emphasises, polynucleotides are the treatment I most often reach for at my clinic in Hale, near Altrincham. They do not add volume or change the shape of your face. They work on the quality of the skin: its hydration, its elasticity, and the collagen and elastin that give it resilience.
I am Dr Caroline Warden, an NHS GP with over nineteen years of clinical experience, an independent prescriber and a Level 7 qualified aesthetic doctor trained at Harley Academy, practising aesthetic medicine since 2017. Every polynucleotide consultation, treatment and review at the clinic is carried out by me personally. I use Plinest® by Mastelli, a Class III medical device containing Polynucleotides HPT, placed with a cannula under local anaesthetic so the treatment is quick and comfortable, including in the delicate under-eye area. The clinic was named Best Doctor-Led Aesthetic Clinic in Cheshire 2026 by GHP.
Polynucleotides sit at the heart of my skin-first approach: for many of the concerns patients bring me, improving the skin gives a more natural result than adding anything to it.
Good to know
A course of three treatments, three to four weeks apart. Cannula technique with local anaesthetic, so quick and comfortable. Mild swelling for a day or two, more noticeable under the eyes. Results build over weeks and through the course. From £255 per session; add NCTF to any session for £40, which I recommend.
On this page:
- What are polynucleotides and how do they work?
- What does the evidence show?
- What can polynucleotides treat?
- Polynucleotides for under eyes
- Polynucleotides vs Profhilo, skin boosters and filler
- Why I use Plinest, and why I add NCTF
- What to expect at your appointment
- Results, course and how long they last
- Safety and suitability
- Prices
- Frequently asked questions
What are polynucleotides and how do they work?
Polynucleotides are highly purified chains of DNA fragments, derived from fish and manufactured for medical use. Online they are nicknamed "salmon DNA injections", which is accurate as far as it goes and misleading in every other respect: they are not raw fish tissue, they are not stem cells, and they cannot alter your own DNA.
Injected into the dermis, they act as a biostimulatory treatment. Their main proposed action is on fibroblasts, the cells that make collagen, elastin and the matrix that holds the skin together. As we age, fibroblasts slow down, collagen fragments and elastin loses its organisation, and we see the result as skin that is thinner, crepey and slow to spring back. Polynucleotides create an environment that supports fibroblast activity and matrix renewal, so the skin gradually rebuilds its own structure rather than having a problem masked with volume. They also hold water, which is why hydration improves early.
After injection they are broken down by the body's own enzymes into components that are reused or cleared. They are biodegradable, they do not accumulate, and they do not integrate with your genetic material. What persists is the collagen response they have set in motion.
What does the evidence show?
I am enthusiastic about polynucleotides and I am also precise about what the research supports. A 2025 systematic review in the Journal of Cosmetic Dermatology examined nine studies covering 219 patients and found that polynucleotide injections had shown
"promising outcomes in reducing wrinkles, improving skin texture, and enhancing elasticity"
Lampridou S et al., Journal of Cosmetic Dermatology, 2025
The same review noted that the studies were small and of low to moderate quality, and that more rigorous trials are needed. A separate 2025 meta-analysis of five randomised trials and 315 patients found statistically significant improvements in dermal elasticity and hydration compared with placebo. A randomised split-face trial in the periocular area reported improvement with polynucleotides, and a 2026 observational study of the under-eye area found improvement in under-eye wrinkles and crow's feet, most marked after the second treatment.
Dr Caroline's note
So here is how I describe polynucleotides to patients: a promising, evidence-based option for improving skin quality, with a good safety record and results that are real but gradual. Not a miracle, not a filler, and not the answer to every tired-looking eye. The skill is in choosing the right patient, and that is what the consultation is for.
What can polynucleotides treat?
Polynucleotides can be used alone or within a wider plan alongside medical-grade skincare, microneedling or NCTF. The deciding question is always whether improving the skin itself is likely to make a visible difference to the concern you have.
Polynucleotides for under eyes
The under-eye is where polynucleotides have changed my practice most. The skin here is the thinnest on the face and becomes more fragile with age, so crepiness, fine lines and a tired appearance show early. For a large group of patients the problem is skin quality, not missing volume, and for them treating the skin gives a fresher, more natural result than anything else, without the risks of filler in this area.
Most tired-looking eyes are a mix of two or three of these, which is why I assess before I recommend and why I never plan an under-eye treatment from a photograph. The result to expect is skin that looks smoother, stronger and less tired, with your natural anatomy unchanged.
Polynucleotides vs Profhilo, skin boosters and dermal filler
Patients often ask which is "best". They are different tools for different problems, and the right one depends on what is actually causing the change you have noticed.
I wrote about combining these in why I combine polynucleotides with skin boosters and in polynucleotides: what they are, how they work and who they suit.
Why I use Plinest, and why I add NCTF
There are now many polynucleotide products on the market and they are not interchangeable. I use Plinest® by Mastelli, part of the PN HPT® (Polynucleotides High Purification Technology) range. Mastelli is an established Italian biopharmaceutical company with a long history in dermatology and tissue repair, the product is a Class III medical device, and it has the largest body of published research of any polynucleotide I have reviewed. Before any injectable comes into my clinic I want to know who makes it, what it contains, how it is purified, its device status and what the evidence says. Plinest answers all of those.
Alongside it I add NCTF® 135 HA, a FILLMED skin booster of non-crosslinked hyaluronic acid with vitamins, amino acids, minerals and antioxidants, licensed for the periorbital area. The two do different jobs: Plinest rebuilds the skin's structure, NCTF gives it the hydration and radiance to match. Each is well evidenced on its own, and I recommend the combination to almost every polynucleotide patient because the results are consistently better together: the surface looks fresher sooner, and the regenerative change underneath has better-hydrated skin to work in. It adds a few minutes and £40 to each session. Read more on my skin boosters page.
What to expect at your appointment
Good to know
Expect mild redness, small areas of swelling, tenderness and possibly a bruise. Under-eye puffiness can look more noticeable the next morning because the area holds fluid; it settles over one to three days and is not a complication. For the rest of the day avoid rubbing the area, strenuous exercise, saunas, alcohol and make-up over the entry points. Continue daily SPF. Plan treatment at least two weeks before an event.
Frequently asked questions
Are polynucleotides worth it?
For the right patient, yes: thin, crepey skin, fine lines and declining skin quality rather than lost volume. The evidence is encouraging and still developing, and the results are gradual and natural rather than dramatic.
How many polynucleotide treatments will I need?
Usually a course of three, three to four weeks apart, then a single maintenance session when your skin needs it, typically every six to twelve months.
When will I see results?
Early hydration within weeks, sooner with NCTF added; the clearer change in texture and resilience after the second and third sessions.
How long do polynucleotide results last?
Published studies show improvement still present at six months. It varies with age, skin, sun exposure and lifestyle, so I assess rather than promise a number, and a maintenance session at £295 keeps it going.
Do polynucleotides add volume?
No. They improve skin quality. If your concern is a true hollow, a different treatment may be more appropriate.
Are polynucleotides good for under eyes?
Yes, for crepey, thin or finely lined under-eye skin. A randomised split-face trial and a 2026 under-eye study both reported improvement. They will not correct every cause of tired-looking eyes.
Do polynucleotides get rid of dark circles?
Only the part caused by thin skin. Pigmentation, shadow from a hollow and puffiness need different approaches, which is why I assess the cause first.
Are polynucleotides better than tear trough filler?
They do different things. Polynucleotides improve the skin; filler replaces volume. For most of the under-eyes I see, the skin is the problem, and I favour the skin-quality route.
Are polynucleotides the same as Profhilo?
No. Profhilo is hyaluronic acid for hydration and early laxity; polynucleotides are DNA fragments for skin regeneration. Both can be part of a plan.
Can polynucleotides be combined with NCTF?
Yes, and I recommend it. Polynucleotides for regeneration, NCTF for hydration and radiance, in the same session through the same entry point, for £40 extra.
Can I have polynucleotides if I have a fish allergy?
No. Plinest is fish-derived and the manufacturer lists fish hypersensitivity as a contraindication. Tell me about any allergy at consultation and we will discuss alternatives.
What are "salmon DNA injections"?
The social media name for polynucleotides: purified DNA fragments from fish, manufactured for medical use. Not raw fish tissue, and they cannot change your own DNA.
What happens to polynucleotides after they are injected?
They are biodegradable and broken down by the body's own enzymes. They do not accumulate and do not integrate with your genes. The collagen response they trigger is what lasts.
Does polynucleotide treatment hurt?
Very little. Local anaesthetic at the entry point and a cannula rather than multiple needles mean most patients feel pressure and an awareness of movement, and nothing more. The treatment is quick.
How much downtime is there?
A day or two of mild swelling, more noticeable under the eyes the next morning. Most people carry on as normal.
Can I have polynucleotides during pregnancy or breastfeeding?
No. There is not enough safety evidence for an elective treatment in this period; we reconsider afterwards.
What age should you start?
There is no ideal age. Some people have genetically thin under-eye skin in their thirties; others keep excellent skin quality much later. The indication is what I see and what bothers you.
Can polynucleotides replace good skincare?
No. Daily SPF, appropriate skincare and not smoking remain the foundation. Polynucleotides are one part of long-term skin health, not a substitute.
Related reading
- Under-eye treatment: dark circles, hollows and crepey skin
- Polynucleotides: what they are, how they work and who they suit
- Why I combine polynucleotides with skin boosters
- Polynucleotides for perimenopausal and menopausal skin
- Why collagen declines and the treatments that actually stimulate it
- Skin boosters: Profhilo, NCTF and Redensity
- Neck and décolletage treatment
Next steps
Learn more about Dr Caroline Warden Clinic
Learn more about other treatments offered
References
- Lampridou S, Bassett S, Cavallini M, Christopoulos G. The effectiveness of polynucleotides in esthetic medicine: a systematic review. J Cosmet Dermatol. 2025;24(2):e16721.
- Efficacy and safety of polynucleotides in esthetic medicine: a systematic review and meta-analysis. Actas Dermo-Sifiliográficas. 2025.
Written and medically reviewed by Dr Caroline Warden, NHS GP with over 19 years of clinical experience, independent prescriber and Level 7 qualified aesthetic doctor (Harley Academy). GMC 6157708. Dr Caroline Warden Skin & Aesthetic Clinic, 2 Crown Passages, Hale, Altrincham, Cheshire WA15 9GN. Results vary between individuals; suitability is determined at a face-to-face consultation. Last reviewed: 2 October 2026.
Jessica’s Polynucleotides + NCTF Before and afters for under eyes
Helen’s Polynucleotides + NCTF Before and afters for under eyes
