Polynucleotides vs Tear Trough Filler Under Eyes: The Real Comparison

Polynucleotides and tear trough filler are both injectable treatments for the under-eye area, but they work differently, suit different concerns, and carry different risk profiles. Most patients are recommended one or the other at consultation without fully understanding why. 

This guide explains the real difference between the two, who each one suits, and why polynucleotides are increasingly the first recommendation for most under-eye concerns. For the full guide to how polynucleotides work and what to expect, visit our polynucleotide treatment guide.

The simplest way to understand the difference is this: polynucleotides fix the skin. Tear trough filler fills a gap.

Polynucleotides are purified DNA fragments, typically derived from salmon or trout. You may have heard them called salmon sperm injections. When injected into the skin beneath the eye, they trigger the skin cells responsible for making collagen and elastin to become more active. Over several weeks, the skin becomes thicker, firmer, more hydrated and more resilient. Dark circles or fine lines improve because the quality of the skin itself has improved. No volume is added.

Tear trough filler is hyaluronic acid gel, a substance the body produces naturally and that is found in many skincare products. When injected into the groove beneath the eye (called the tear trough), it physically fills the space, lifting the skin and reducing the shadow. Results are visible the same day because the gel is sitting there creating volume. The skin quality has not changed at all.

This is the most important distinction. A patient whose dark circles are caused by thin, see-through skin that lets blood vessels show through will not see meaningful improvement from filler. Their skin is the problem, not the lack of volume. A patient whose dark circles are caused by a hollow groove beneath the eye may not see meaningful improvement from polynucleotides alone. Their structure is the issue, not the skin quality. Getting this right at consultation is the difference between a good result and money spent on the wrong treatment.

A 2022 randomised, double-blind, split-face trial published in the Journal of Dermatological Treatment compared polynucleotide injections directly to non-crosslinked hyaluronic acid filler in the area around the eye across 27 subjects. The polynucleotide group showed higher improvement rates in skin elasticity, hydration, roughness and pore volume. Both were found to be effective and safe for rejuvenating the skin around the eye.

The skin beneath the eye is around 0.5mm thick. The skin on the rest of the face is typically 2mm thick. This makes the under-eye area the most delicate skin on the face by a significant margin.

Under this thin skin sits a network of small blood vessels, very little fat for cushioning, and almost no oil glands. This is why the under-eye area:

• Shows dark circles when blood vessels are visible through thin skin
• Shows hollowing when the small fat pockets beneath the eye reduce with age
• Develops fine lines and crepey texture earlier than the rest of the face
• Responds differently to injectables than thicker facial skin
• Requires significantly more technical skill to treat safely

Any treatment in this area carries more risk than the same treatment elsewhere on the face. This is true of both polynucleotides and tear trough filler. But the risk profiles are not equal.

Tear trough filler is effective for the right patient, but the risk profile in this area is meaningfully higher than for filler placed elsewhere on the face. Patients considering tear trough filler should understand these risks before proceeding.

Visible bluish discolouration (the Tyndall effect). This happens when filler is placed too close to the surface of the skin. Because the skin here is so thin, gel placed too superficially becomes visible as a bluish or grey tint beneath the skin. It is one of the most frequently reported complications specific to tear trough filler and can persist until the filler is dissolved. A 2024 study published on PMC specifically noted that conventional fillers in the area around the eye carry higher risks of swelling, irregularities and this type of discolouration compared to polynucleotides.

Persistent swelling. Hyaluronic acid attracts water. In the thin, fluid-prone tissue beneath the eye, this can lead to persistent puffiness that makes the under-eye area look worse rather than better. This risk is higher in patients who are prone to fluid retention or have excess skin in the area.

Blood vessel risk. The under-eye area has a high density of small blood vessels (it is highly vascular, meaning there are lots of blood vessels close to the surface). Accidental injection into or near a vessel carries risks including bruising, skin damage and in very rare cases more serious complications. Precise knowledge of the anatomy here is essential.

Migration. Filler can move from the original placement site over time. In thin-skinned areas like the under-eye, migration can create lumps, asymmetry or visible irregularities beneath the skin.

Poor skin quality is a contraindication. Patients with excess skin, poor skin quality, visible eye bags caused by fat pushing forward, and fluid retention around the eye are all poor candidates for tear trough filler. This matters because many patients presenting with dark circles have exactly these features.

None of this means tear trough filler is the wrong choice. It means the right patient must be selected, and the practitioner must be highly experienced specifically in this area.

Polynucleotides carry a lower risk profile in the under-eye area than tear trough filler. The main reasons are that no volume is being added, which removes the risks of visible discolouration and swelling from volume, and the product is highly compatible with human tissue. A 2024 review published in the International Journal of Molecular Sciences confirmed polynucleotides have a high compatibility with the body and a favourable safety profile, making them specifically suited to delicate areas like the skin around the eye.

The main risks specific to this area are:

• Temporary swelling and redness at injection sites, typically resolving within 24 to 48 hours
• Bruising, which is more common beneath the eye than elsewhere and resolves within 5 to 7 days
• Temporary puffiness as the product draws moisture to the tissue, which is a normal response and settles
• Allergic reaction in patients with fish or seafood sensitivity. This is an absolute contraindication and must be screened for before treatment
• Fluid pooling in the cheek area below the under-eye (called malar oedema), which can occur with any injectable treatment in this area and typically resolves without intervention

Fish or seafood allergy, pregnancy, breastfeeding and active autoimmune conditions are all contraindications for polynucleotide treatment.

Dark circles look the same from the outside but have very different causes beneath the surface. The cause determines the right treatment. Treating the wrong cause means no result regardless of which treatment is used.

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A 2026 real-world clinical study on polynucleotides for pigmentation around the eye, published in Clinical, Cosmetic and Investigational Dermatology, confirmed that polynucleotides can reduce the amount of pigment (melanin, which gives skin its colour) the skin produces. This directly addresses dark circles caused by too much pigmentation in the skin. For dark circles caused by structural hollowing, this mechanism has no effect, and filler remains the more targeted option.

The most important thing a good practitioner does at consultation is identify which of these causes applies to you before recommending any treatment. Use our questions to ask at your polynucleotide consultation to make sure you are asking the right things before committing to either treatment.

Polynucleotides suit patients whose primary under-eye concern is skin quality rather than structure. Good candidates include:

• Patients with thin, crepey or papery skin texture beneath the eyes
• Patients with dark circles caused by the skin being so thin that blood vessels show through
• Patients with dark circles caused by too much pigment in the skin
• Patients with fine lines beneath the eyes and in the crow’s feet area
• Patients with dehydrated under-eye skin that looks dull regardless of sleep
• Patients who have been told they are not suitable for tear trough filler due to poor skin quality
• Patients who want to improve their skin quality before considering tear trough filler
• Patients with mild puffiness related to poor skin tone rather than fat pushing forward

Patients who are not suitable for polynucleotides include those with fish or seafood allergies, those who are pregnant or breastfeeding, those with active autoimmune conditions, vegans (most products are fish-derived), and those whose primary concern is significant structural volume loss rather than skin quality.

For a full breakdown of what results look like, visit our polynucleotides before and after guide.

Tear trough filler suits a narrower group of patients than many assume. Good candidates are:

• Patients with good skin quality who have a specific, defined hollow along the bony ridge beneath the eye
• Patients whose dark circles are caused primarily by structural volume loss creating a shadow
• Patients without excess skin, fluid retention or fat pushing forward in the under-eye area
• Patients who want immediate, visible correction and understand the maintenance requirement
• Patients who are comfortable with the risks involved and the possibility of needing the filler dissolved

Poor candidates for tear trough filler include patients with excess skin beneath the eye, patients prone to fluid retention or puffiness, patients with poor skin quality in the area, patients with visible fat pushing forward or eye bags, and patients with dark circles caused by pigmentation rather than structural loss. For these patients, polynucleotides are typically recommended first.

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The biggest practical difference is speed. Tear trough filler produces visible results the same day. Polynucleotides take 3 to 6 weeks for the first visible change and 2 to 3 months to reach peak results. Patients wanting a result before a specific event are better served by tear trough filler, provided they are suitable candidates. Patients investing in long-term skin improvement are better served by polynucleotides.

To see what real patient results look like across a course of treatment, visit our polynucleotides before and after guide.

Yes, and many experienced practitioners recommend both for patients who have skin quality concerns alongside structural hollowing. The approach matters though.

Polynucleotides are typically used first. A course of polynucleotides improves the skin quality, making the tissue thicker and more resilient. This serves two purposes: it directly improves the skin-quality concerns that filler cannot address, and it makes the patient a better candidate for tear trough filler if hollowing remains after the polynucleotide course. Thicker, better-quality skin reduces the risk of visible discolouration and migration when filler is later added.

Experienced practitioners find that completing a polynucleotide course first can make a meaningful difference for patients who may not have been strong filler candidates initially, improving both the result and the safety of any subsequent filler treatment.

The two treatments are not typically given at the same session. They are planned in a sequence. This should be discussed at your consultation with a practitioner who treats the under-eye area regularly. Use our questions to ask at your polynucleotide consultation to prepare before you go.

For the full guide to polynucleotide under-eye treatment including what to expect week by week and which products are used, visit our polynucleotides under eyes guide.

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Polynucleotides cost more across the initial course because multiple sessions are needed. Tear trough filler is a higher cost per session but usually requires just one. Over two to three years the total spend is often comparable. The more important question is which treatment suits the concern, not which is cheaper per visit.

Most patients presenting with under-eye concerns have some combination of thin skin, poor texture, pigmentation and dehydration. These are all skin quality issues. Tear trough filler does not address skin quality at all.

Additionally, the under-eye area carries the highest risk for filler complications of almost any area on the face, precisely because the skin is so thin. Poor skin quality increases that risk further. Polynucleotides improve the skin first, reduce risk, and in many cases resolve enough of the concern that filler is not needed at all.

This does not mean filler is the wrong choice. For patients with clear structural hollowing and good skin quality, filler remains the more targeted and immediate solution. The two treatments are not competing with each other. They treat different things. The right one depends entirely on what is causing the concern in your specific anatomy.

For everything about how polynucleotides work, what they treat and what results look like, visit our full polynucleotide treatment guide and polynucleotides under eyes guide.

Every polynucleotide clinic listed on The Aesthetic Standard is manually reviewed before being included. We check:

Statutory medical registration: General Medical Council (GMC) for doctors, General Dental Council (GDC) for dentists, Nursing and Midwifery Council (NMC) for nurses. For non-medically registered practitioners: Ofqual-regulated Level 4 qualification in Laser and IPL at minimum and a named medical oversight arrangement. Professional body membership: British College of Aesthetic Medicine (BCAM) or British Association of Medical Aesthetic Nurses (BAMAN). Care Quality Commission (CQC) registration where held. Local authority licensing where required. Voluntary accreditation with Save Face or the Joint Council for Cosmetic Practitioners (JCCP). Professional indemnity insurance specifically covering polynucleotide treatment. Independent patient feedback across Trustpilot and Google. Where possible we speak directly with patients who have undergone treatment at the clinic.

A listing on The Aesthetic Standard is not a guarantee of outcome. It is confirmation that the clinic has met our verification criteria and that the practitioner holds the appropriate credentials to perform this treatment safely. Read our full verification criteria before choosing a clinic.

Each city page covers local pricing, verified practitioners and how we select clinics in that area:

Polynucleotide clinics in London
Polynucleotide clinics in Manchester
Polynucleotide clinics in Birmingham

For everything about how polynucleotides work, what results look like and how to choose a clinic, visit our polynucleotide treatment guide, polynucleotides under eyes guide and polynucleotides before and after guide. Browse our full clinic directory to find verified practitioners across London, Manchester and Birmingham.

The Aesthetic Standard. Clinics You Can Trust.

Lee YJ et al. Comparison of the effects of polynucleotide and hyaluronic acid fillers on periocular rejuvenation: a randomized, double-blind, split-face trial. Journal of Dermatological Treatment. 2022;33(1):254-260. View study

Review of polynucleotides in aesthetic medicine. International Journal of Molecular Sciences. 2024;25(15):8224. View study

Prospective observational study of polynucleotide injections for the skin around the eye. 2025. View study

Real-world study of polynucleotides HPT for treating pigmentation around the eye. Clinical, Cosmetic and Investigational Dermatology. 2026. View study