What are Polynucleotides? The Science Behind the Salmon Sperm Facial

Patients ask me all the time: "Is this the salmon sperm thing?"

Yes. And no.

Let me explain. The DNA used in polynucleotide treatments is extracted and purified from salmon. But by the time it reaches you as a medical-grade injectable, it bears no resemblance to anything biological in the conventional sense. No smell. No appearance. No cells, proteins, or debris of any kind. What remains is a clear, sterile solution of purified DNA fragments, a molecule your body's own repair machinery already knows exactly how to use.

Here's what actually makes this interesting to a former cardiac nurse: these fragments do not work by injuring tissue or adding volume. They work by talking to your cells. They bind to specific receptors on your fibroblasts and instruct those cells to switch on the genes responsible for collagen, elastin, and hyaluronic acid production. Your skin repairs itself. The treatment just provides the signal.

That distinction, signalling rather than injury, is the entire reason polynucleotides deserve a different conversation from the rest of the aesthetic menu.

What polynucleotides actually are

Polynucleotides, also called PDRN or polydeoxyribonucleotides, are long-chain DNA fragments purified from salmon sperm cells. Salmon DNA has a high structural compatibility with human DNA, which is precisely why it works so well as a biological signalling molecule in human tissue.

This is not a new discovery. PDRN received pharmaceutical approval in Italy in 1994 for the treatment of superficial wounds, skin ulcers, and connective tissue disorders. Over 30 years of approved clinical use in wound healing and tissue repair preceded its entry into aesthetic medicine. That medical heritage is what sets it apart from trend-driven treatments that arrive with marketing budgets but limited evidence.

The key facts, honestly stated:

• What it is: Purified DNA fragments injected into the dermis

• What it does: Activates fibroblasts via adenosine A2A receptors to produce collagen, elastin, and hyaluronic acid

• What it is not: A filler, a volume treatment, a wrinkle relaxer

• Timeline: Results build gradually over 8 to 12 weeks

• Downtime: Minimal, typically 24 to 48 hours of mild swelling

The biology, without the jargon

Most patients don't need the full molecular pathway. But the broad strokes matter, because understanding why this treatment works differently helps set realistic expectations.

When polynucleotides are injected into the dermis, your own cellular enzymes break the long DNA chains down into smaller fragments. Those fragments then bind to adenosine A2A receptors on the surface of fibroblasts, the cells responsible for producing your skin's structural proteins. This binding activates a cascade that tells those fibroblasts to increase collagen production, synthesise new elastin, and generate hyaluronic acid naturally within the extracellular matrix.

A 2025 comparative review published in PMC confirmed that PDRN selectively activates the A2A receptor, modulating inflammation, stimulating angiogenesis, and enhancing collagen production in dermal fibroblasts. This mechanism has been replicated consistently across decades of peer-reviewed research.

Two additional benefits are worth understanding. First, polynucleotides suppress pro-inflammatory cytokines, the chemical signals driving the chronic low-grade inflammation that accelerates skin ageing. Second, the salvage pathway activated alongside the A2A receptor supports DNA repair in cells that have been damaged by UV radiation. This is not simply a surface improvement. The treatment is addressing some of the underlying biology of ageing skin at the cellular level.

A 2025 systematic review in the Journal of Cosmetic Dermatology concluded that polynucleotide injections show statistically significant results in reducing wrinkles, improving skin texture, and enhancing elasticity, with a favourable safety profile and moderate to high patient satisfaction.

The salmon source, addressed directly

I want to deal with this head-on because patients deserve a clear answer.

The salmon DNA used in medical-grade polynucleotide products is extracted and purified to remove all cells, proteins, lipids, and biological debris. The purification process is rigorous, and the final product is tested extensively before it reaches clinical use. What you receive is a sterile, clear medical solution consisting only of DNA fragments. Nothing that smells, looks, or behaves like salmon in any way.

The reason salmon is used is biological logic. Salmon DNA has a molecular weight range and structural composition that is highly compatible with the human adenosine receptors these fragments need to bind. There is also a long track record of safety. Decades of clinical data show that salmon-derived PDRN has an excellent biocompatibility profile with minimal adverse reactions in appropriately screened patients.

How polynucleotides compare to other treatments

This is the question that matters most for most patients. The table below is the honest version.

	Polynucleotides	Dermal fillers	Botox	Profhilo	Sculptra
Mechanism	Cellular regeneration via A2A receptor signalling	Volume replacement with hyaluronic acid	Muscle relaxation via neurotoxin	Hydration and mild bio-remodelling via HA	Collagen stimulation via PLLA microparticles
Result timeline	8 to 12 weeks	Immediate	3 to 7 days	2 to 3 weeks	3 to 6 months
Primary benefit	Skin quality, texture, UV repair, inflammation control	Contour, lips, folds, volume	Expression lines, wrinkle prevention	Dehydration, mild laxity	Volume loss, structural support
Downtime	Minimal	Minimal	Minimal	Minimal	Minimal to moderate
Reversible	Yes, naturally metabolised	Yes with hyaluronidase	Yes, wears off	Yes, naturally metabolised	No

The most important thing that table shows is that polynucleotides occupy a completely distinct category. They do not add volume, relax muscles, or provide immediate visible change. What they do is improve the fundamental quality of the tissue itself. Firmer, healthier, better-hydrated skin that holds other treatments better and ages more slowly going forward.

Many of my patients use polynucleotides as a regenerative foundation alongside other treatments in a personalised combination protocol, precisely because improving tissue quality first makes everything else work better.

What results actually look like

Managing expectations honestly is something I care about deeply. Polynucleotides are not an instant-result treatment. Patients who understand the biology tend to find the gradual timeline reassuring rather than frustrating, because they know what is actually happening in the tissue.

• Weeks 1 to 4: Subtle improvement in skin texture and hydration as initial fibroblast activity begins

• Weeks 4 to 8: Noticeable increase in firmness and smoothing of fine lines as new collagen integrates

• Weeks 8 to 12: Peak remodelling phase. Skin looks measurably healthier, firmer, and more luminous

• Months 3 to 6: Sustained improvement continues even after the polynucleotide itself has metabolised, as activated fibroblasts remain in a heightened state of function

A standard course is two sessions spaced four weeks apart. Maintenance is typically one session every six to twelve months, depending on age and skin condition.

Who is right for polynucleotides?

This treatment suits a wide range of patients and concerns. It works particularly well for:

• Dull, dehydrated skin that has lost its natural vitality

• Fine lines and early skin laxity where volume is not the primary concern

• Patients who have experienced sun damage and want to address it from within

• Anyone who wants to improve the fundamental quality of their skin rather than alter its structure

• Patients looking for a regenerative foundation before or alongside other treatments

• Those who prefer a treatment with minimal downtime and no risk of looking overdone

It is not the right choice if your primary concern is significant volume loss or deep structural change. For those situations, dermal filler or threads are more appropriate, and that is a conversation worth having honestly at consultation.

Frequently asked questions

Is this the same as the "salmon sperm facial"? It uses DNA extracted from salmon, yes. But the final product is a purified, sterile medical solution with no resemblance to biological material. The nickname is attention-grabbing but misleading about what the treatment actually involves.

How is this different from Profhilo? Profhilo is a hyaluronic acid bio-remodeller. It improves hydration and triggers collagen via a spreading mechanism. Polynucleotides work via the A2A receptor to drive cellular regeneration directly. Different mechanisms, different results, and they complement each other well. Many patients benefit from both in a phased approach.

Will I see an immediate difference? Some patients notice improved hydration within the first week or two, but visible structural improvement builds gradually over 8 to 12 weeks. This is by design, real collagen remodelling takes time. Patients who want immediate visible change are often better served by a different treatment first.

Is it safe? The safety profile of PDRN and polynucleotide injectables is well established across over 30 years of clinical and pharmaceutical use. Side effects are typically mild and transient, most commonly temporary swelling and occasional bruising at injection points. A thorough medical consultation identifies any contraindications beforehand.

Can it be combined with other treatments? Yes. Polynucleotides combine well with Profhilo, microneedling, and red light therapy. Many patients use them as part of a broader regenerative protocol that addresses both tissue quality and specific concerns simultaneously.

Key takeaways

Polynucleotides are not a trend. They have 30 years of pharmaceutical history behind them. The mechanism is documented, replicated, and increasingly well understood. And the results, when patients come in with the right expectations, are genuinely impressive.

What I offer at Juvenology is not just the treatment. It is the clinical conversation that makes sure you leave with both the outcome you were hoping for and the understanding of why it happened. That combination of science and honest communication is what I brought from cardiac nursing into aesthetics, and it does not change regardless of which treatment we are discussing.

"In 30 years of clinical use, polynucleotides have proven themselves in wound wards, in diabetic ulcer clinics, and now in aesthetic practice. When a treatment earns that kind of track record, it is not a trend. It is biology that works. And biology that works is exactly what this clinic is built on." Nurse Marina, Juvenology Clinic

About the author

Nurse Marina is an aesthetic nurse specialist based in Maidstone, Kent, with over 25 years of nursing experience including six years in cardiac care at KIMS Hospital. She specialised at Spencer Private Hospitals before founding Juvenology, a longevity-focused aesthetic clinic combining regenerative medicine with evidence-based practice.

Marina is NMC Registered, BACN Member, JCCP Verified, ACE Group Registered, and a Member of the Royal College of Nursing.

Book a polynucleotide consultation at Juvenology Clinic, Maidstone, Kent