What Are Polynucleotides? Treatment, Under-Eye Use and What to Expect
Updated: 1 day ago
Polynucleotides are injectable treatments made from purified fragments of fish DNA. They are used to try to improve skin quality (fine lines, crepey texture, firmness and hydration) rather than to add volume or change the shape of the face. [1, 2] Results, when they come, are gradual and subtle. The research is promising in places but still limited: most studies are small, short and funded by manufacturers, and different products should not be treated as the same thing. [10, 12]
This guide from Juvenology Clinic in Maidstone explains what polynucleotide treatment involves, whether it can help under the eyes, what to expect before and after, the risks and costs, and how it compares with other options.
What are polynucleotides made of?
Polynucleotides are chains of nucleotides, the building blocks of DNA. In aesthetic treatments, the term refers to purified DNA fragments taken from the reproductive cells of salmon or trout and processed into a sterile gel for injection. [1, 2]
You may hear two terms. Polynucleotides (PN) usually describes longer DNA chains, and polydeoxyribonucleotides (PDRN) usually describes shorter ones. There is no agreed cut-off between the two, and manufacturers rarely disclose chain length. [1, 3] The distinction matters because much of the laboratory research on how these molecules work used PDRN, not the longer-chain products used in aesthetic clinics. [4]
Products sold under the same label also differ in source, purification, concentration and added ingredients such as hyaluronic acid. One manufacturer's range, for example, includes a 20 mg/mL product, a weaker formulation for the eye area and a polynucleotide-hyaluronic acid combination. [5, 6, 7] Research on one brand cannot simply be applied to another, so ask exactly which product is proposed for you, at what strength, and what evidence exists for it in that area.
The "salmon sperm facial" nickname is memorable but inaccurate. The treatment is a manufactured, purified medical device, it is injected rather than applied as a facial, and some products come from trout. [2]
Are polynucleotides vegan? No. They are made from fish DNA. [1, 2]
Can they change my DNA? Reviews describe injected polynucleotides being broken down by the body's own enzymes into smaller components. [3] There is no evidence that they alter a person's own genetic material, although this has not been studied directly.
How are polynucleotides thought to work?
Several mechanisms have been proposed. Most of the evidence for them comes from laboratory, animal or wound-healing research rather than from aesthetic treatment in people.
Supporting skin cells. In laboratory and animal studies, DNA-derived products increased the activity of fibroblasts, the cells that make collagen. [8, 9]
Adenosine A2A receptors. Research on PDRN suggests it acts through receptors involved in tissue repair and inflammation, shown mainly in laboratory and wound-healing work. [9, 1] A 2024 review found no objective data showing the same mechanism for the longer-chain PN used in aesthetics. [4]
Building blocks for repair. As the fragments break down, they may supply nucleotides that cells can reuse, a proposed mechanism based mainly on PDRN research. [9]
Hydration and support. Longer-chain PN forms a water-holding gel, and some researchers suggest much of its effect comes from hydration and structural support. [1]
Phrases such as "regenerates your skin" or "repairs your DNA" go beyond what human aesthetic studies have shown. So far, the mechanisms are plausible and backed by laboratory work, but the clinical evidence comes from a limited number of small studies.
Polynucleotides under the eyes
The under-eye area is one of the most common reasons people ask about polynucleotides. "Under-eye concerns" covers several different problems, though, and they need different approaches.
Concern | What causes it | Have polynucleotides been studied for it? |
Fine lines and crepey texture | Thin, less elastic skin | Yes, in small studies: fine lines and texture [14, 13] |
Dark circles from pigmentation | Excess pigment in the skin | One uncontrolled, manufacturer-funded study reported improvement on a clinician photo scale [18] |
Dark circles from visible vessels or thin skin | Blood vessels showing through thin skin | Not enough people with this type have been studied to say [18] |
Hollowing (tear trough) | Loss of volume and bony structure | Not measured directly; the dark-circle study did not measure volume [18]. Polynucleotides are not designed to restore volume |
Bags and puffiness | Fat bulging forward, fluid, or lax skin | Not studied. Surgical or other assessment may be appropriate |
In the main dark-circle study, 61 adults had three sessions of an eye-specific product and were followed for three months. Clinicians rated their dark circles as less severe overall, but the study had no comparison group, was funded by the manufacturer, and about a third of participants had mild swelling or redness. [18] A review of 23 patients' records over about two years reported two mild, self-limiting side effects after under-eye treatment, one of them small bumps that lasted longer than usual. [19]
If your main concern is fine lines or crepey texture under the eyes, polynucleotides may be a reasonable option to discuss. If it is a hollow, bags or marked puffiness, they are unlikely to help on their own, and another treatment or a specialist opinion may be more appropriate. For hollowing, that might mean a volume treatment such as tear trough filler, which is assessed separately and has its own risks. Polynucleotides do not fill tear troughs. The skin under the eyes is delicate, so this area needs particular care in assessment and treatment.
What benefits have been studied?
A 2025 systematic review found nine studies, with 219 patients in total, of polynucleotides in aesthetic medicine. None scored full marks for quality, and none reported serious side effects. [10] The review has important limitations. At least two of the nine studies involved PDRN. One included trial was later retracted after its manufacturer funding was found to be inaccurately disclosed. [11] Several authors have links with a polynucleotide manufacturer or its UK distributor. [10] A 2026 review of randomised trials found seven, with 183 participants, and concluded that the evidence is limited by small samples and unstandardised preparations. [12]
Outcome | What the studies found | How strong the evidence is |
Fine lines and crow's feet | In a trial against another injectable, results were similar at 12 weeks. [13] In a trial against hyaluronic acid around the eyes, people and assessors rated both sides similarly. [14] | Small trials with no untreated group |
Skin texture | Around the eyes, skin roughness and pore volume improved more on the polynucleotide side than the hyaluronic acid side, on instrumental measurements. [14] | One small split-face trial (27 people) |
Hydration and elasticity | Measured improvements on both sides of the same trial, somewhat greater with polynucleotides, but declining over time. [14] | As above |
Acne scars | Improvement compared with saline in a trial of 20 women over 3 months. [15] An uncontrolled study of 30 people using a polynucleotide and hyaluronic acid product reported a 19% fall in scar scores at 3 months and 22% at 6 months. [16] | Small, short; the second is manufacturer-funded and uncontrolled |
Overall skin quality on the face, neck and décolleté | High satisfaction (97–100%) in an uncontrolled study of 66 people over 3 months. [17] | Manufacturer-supported; satisfaction rather than measurement |
If treatment helps, the change is usually subtle: skin that looks a little smoother, more even or more hydrated. Polynucleotides do not replace treatments for lost volume, sagging or other structural change. Small or preliminary reports in hair loss, pigmentation and redness are not enough to recommend them for acne, rosacea, eczema, melasma or hair loss. [10, 4]
Who may be suitable, and who may not
Polynucleotides may be worth discussing if your main concern is skin quality: fine lines, crepey or thin-looking skin, rough texture, or skin that has lost some bounce on the face, under the eyes, on the neck or on the backs of the hands. They are less likely to suit you if your main concern is lost volume, sagging, deep folds or the shape of your face, or if you hope for a dramatic change. Juvenology's guide to neck lines explains which neck changes skin-quality treatments can and cannot help, and the guide to crepey skin treatments compares options for thin, crinkled skin elsewhere on the body.
An assessment should cover what you want to change, your skin and any active skin conditions, your medical history and medicines (including anything that affects bleeding), allergies and previous reactions to injectables, previous treatments in the area, and pregnancy or breastfeeding.
Exact contraindications depend on the product's instructions for use. Commonly listed reasons not to treat include a fish or shellfish allergy, pregnancy or breastfeeding, and active infection in the area. Extra caution is advised with bleeding disorders, blood-thinning medicines and some autoimmune conditions. [20] Because these products are made from fish DNA, a fish allergy is a reason not to proceed.
What polynucleotide treatment involves
Treatment starts with a consultation. You should be told which product is proposed and why, what the evidence shows, the risks, how many sessions might be suggested and the total cost, and you should have time to decide. Juvenology's guide to choosing a skin clinic in Maidstone covers what to look for in any provider. Every polynucleotide treatment at Juvenology is carried out by the founder.
On the day, the skin is cleaned and the product is placed through a series of very small injections. Most people feel a brief sting with each one. You will be given written aftercare advice for the product and area treated, and Juvenology's aftercare guide for injectable treatments explains the general points in advance.
Injections and microneedling are different treatments
Injected polynucleotides are sterile products designed for injection into the skin, and nearly all the clinical evidence in this guide comes from them. [17, 18] Polynucleotides used with microneedling are applied to the skin during a microneedling treatment. That is a separate procedure with a separate evidence base. A small trial of a polynucleotide serum after radiofrequency microneedling found no difference in maximum wrinkle depth compared with saline, although one 3D measure favoured the polynucleotide side. [24]
If you are offered polynucleotides with microneedling, ask which product will be used and whether it is designed for microneedled skin. Products applied to microneedled skin can be carried into deeper layers, and inflammatory lumps have been reported after microneedling with some topical serums. [25] Juvenology lists microneedling with polynucleotides as a separate service from polynucleotide injections.
Polynucleotides before and after: what to expect
Polynucleotides do not give an instant result like filler. The table below sets out what is normal at each stage. Individual experience varies, and your practitioner's written instructions take priority.
When | What is usual | What it means |
Immediately after | Small raised bumps at the injection points, redness and tenderness; possible bruising | Expected after the injections, not the result. Any early plumpness is swelling or product at the injection sites [16, 17] |
First 1–2 days | Bumps usually flatten; redness settles | Avoid make-up for 12 hours, and strenuous exercise, saunas and alcohol for 48 hours (Juvenology's usual advice) |
First week | Any bruising fades over a few days | Contact the clinic if swelling, pain or redness gets worse instead of better |
During the course | Further sessions, typically two to four weeks apart | Studies mostly used three sessions two to three weeks apart [14, 17, 18] |
Weeks to months after the course | Where studies found improvement, it was assessed weeks to a few months after the course | Subtle change in texture, fine lines or hydration, not a change in shape [14, 17] |
Before-and-after photographs online can mislead. Lighting, angle, make-up and the time between photos all change how skin looks, and a photo of one product on one person does not predict your result. Some people notice little change. In one acne-scar study, scar grade had not improved in 30% of participants at six months. [16]
How long do polynucleotides last?
This is not well established. The longest controlled studies followed people for about six months, [26, 24] and the length of a study is not proof of how long an effect lasts. There is no good evidence on how often maintenance sessions are needed, so if you are offered a maintenance plan, ask what it is based on. If you see little benefit after a course, it is reasonable to stop rather than continue indefinitely.
How many sessions? Manufacturers suggest schedules such as three sessions two to three weeks apart, or three to four sessions for an eye product. [5, 6] At Juvenology, most people have two or three sessions, two to four weeks apart. These are typical schedules, not a requirement.
Polynucleotide side effects and safety
No injectable treatment is risk-free. The most commonly reported effects are short-lived swelling, redness, tenderness, bruising and small bumps at the injection sites. [17, 16] In an under-eye study, about a third of people had mild swelling or redness. [18] Reviews of the published studies have not reported serious side effects, [10, 12] but the studies are small and follow people for months rather than years. Even an industry-linked review acknowledges that rare complications "cannot be fully excluded". [21] As with any injection into the skin, infection, allergic reaction and lumps are possible, and any injection near blood vessels carries a theoretical risk of damaging one.
Can polynucleotides be dissolved? Hyaluronidase breaks down hyaluronic acid. [22] It is not established as a way of reversing polynucleotides and would act only on any hyaluronic acid in a combination product. It is safest to treat polynucleotides as something that cannot be undone on request.
When to get help. Contact the clinic that treated you if swelling, redness, pain or lumps get worse rather than better, appear days or weeks later, or come with a fever. Severe or increasing pain, skin that turns pale, blotchy or dusky, or any change in vision after a facial injection are warning signs of a blocked blood vessel. [23] Contact the clinic straight away, and call 999 for any change in vision or signs of a stroke. You can read Juvenology's guidance on when to contact the clinic after treatment before your appointment.
How polynucleotides compare with other treatments
Treatment | Main purpose | Type of change | Evidence | Important limits |
Polynucleotide injections | Skin quality: fine lines, texture, crepiness | Gradual, subtle | Small, mostly short, often manufacturer-funded studies [10] | Product-specific; not volume or lift |
Hyaluronic acid skin boosters, such as Profhilo | Hydration and skin quality | Gradual | Small studies, often manufacturer-funded [27] | Not volume or lift |
Volumising dermal fillers | Volume and contour | Immediate | Larger trials for specific products | Do not improve skin quality in the same way |
Microneedling | Texture and fine lines | Gradual, over a course | Systematic review, mostly wrinkles and texture [28] | Redness is the most common side effect |
Platelet-rich plasma (PRP) | Skin quality | Gradual | Low to very low certainty [29] | Evidence weak |
Skincare and sun protection | Long-term skin quality | Slow | Good for sun protection [30] | No quick change |
Polynucleotides or Profhilo? Both are used for skin quality but contain different materials. Profhilo contains 64 mg of hyaluronic acid in 2 mL, in high- and low-molecular-weight forms. [27] No trial has compared polynucleotides with Profhilo directly. One small trial against a different hyaluronic acid product around the eyes found people and assessors rated both sides similarly, though some instrumental measurements favoured polynucleotides. [14] Claims such as "polynucleotides repair while hyaluronic acid only hydrates" are not supported by direct evidence. Read more in the guide to whether Profhilo is worth it, or see Profhilo treatment at Juvenology.
Doing nothing. Good skincare, daily sun protection and simply waiting are reasonable choices. [30] Skin changes with age are normal, and not every change needs a procedure.
Polynucleotide treatment cost
At Juvenology, polynucleotide treatment is listed at £250 per area per session, or £675 for a prepaid course of three sessions, for the under-eyes, face, neck, décolleté or backs of the hands. Microneedling with polynucleotides is listed separately at £250 per session. Prices were checked on 20 October 2026; please confirm current fees when you book.
When comparing prices elsewhere, ask which product will be used, whether the price is per area or per session, and what the total cost of the suggested plan will be. There is no reliable source for an average UK price.
Frequently asked questions
Do polynucleotides work?
Small studies suggest they can improve aspects of skin quality, such as texture and fine lines. The research is limited and mostly short term, and results vary between products and people. [10, 12]
How long do polynucleotides take to work?
They do not work instantly. Improvement, where studies found it, was assessed weeks to a few months after a course of sessions. [14, 17]
Are polynucleotides the same as PDRN?
No. Both are purified DNA fragments, but PN usually refers to longer chains and PDRN to shorter ones. Much of the laboratory research used PDRN. [1, 4]
Are polynucleotides better than Profhilo?
There is no direct comparison. They contain different materials and may suit different concerns. [14]
Will polynucleotides fill my tear troughs?
No. They are not designed to restore volume, and hollowing under the eyes has not been a measured outcome in the studies. [18]
Can I have polynucleotides if I am allergic to fish?
No. A fish allergy is a reason not to have them, and some guidance also advises against treatment with a shellfish allergy. [20]
Is there any downtime after polynucleotides?
Small raised bumps, redness and tenderness at the injection points are expected straight afterwards, and bruising is possible. [16, 17] The bumps usually flatten within a day or two, and any bruising fades over a few days. Juvenology's usual advice is to avoid make-up for 12 hours, and strenuous exercise, saunas and alcohol for 48 hours.
Are polynucleotides a filler or a skin booster?
They are not designed to add volume like a dermal filler. They are often grouped with skin boosters such as Profhilo because both aim at skin quality, but polynucleotides are made from fish DNA fragments and Profhilo from hyaluronic acid. [1, 27]
Can polynucleotides be combined with other treatments?
Sometimes, but the combination and timing need to be assessed individually, taking into account previous treatments in the area, skin sensitivity and recovery. Polynucleotides used with microneedling are a separate treatment with a separate evidence base, covered earlier in this guide.
Will I need top-ups?
Possibly, but there is little evidence on how often. Controlled studies have followed people for up to about six months. [26, 24]
Thinking about polynucleotides in Maidstone?
If you are wondering whether polynucleotides, another treatment or no treatment is right for your skin, a consultation at Juvenology Clinic in Maidstone gives you time to talk it through. You do not need to choose a treatment before booking, and there is no obligation to go ahead. You can see the areas, prices and booking options on the polynucleotides page, book a consultation, or ask a question first through a free discovery call on WhatsApp. The discovery call is not a clinical assessment.
About the author
Marina Kostadinova-Yankova is the founder of Juvenology Clinic in Maidstone, Kent. She is a registered nurse with the Nursing and Midwifery Council (NMC) and has more than 25 years of nursing experience. She is listed with the Joint Council for Cosmetic Practitioners (JCCP), is a member of the Royal College of Nursing, and has trained in aesthetic injectables with ACE Group and Derma Medical. Read more about Marina.
This article is general information and does not replace individual medical advice. Suitability, benefits and risks can only be judged at a personal assessment. Information was checked in November 2026.
