The short answer
Polynucleotides are purified DNA fragments — typically from salmon — formulated as a sterile injectable. They are a CE-marked Class III medical device. They stimulate tissue repair, hydration, and collagen production.
PRP (platelet-rich plasma) is the patient’s own blood, drawn into a tube, spun in a centrifuge to separate the red cells, and re-injected. The growth factors released by the platelets stimulate tissue repair.
Both are regenerative injectables. Both claim to improve skin quality, reduce dark circles, and stimulate collagen. The differences are in mechanism, consistency, regulatory status, and how they fit into a treatment plan.
Side by side
| Polynucleotides | PRP | |
|---|---|---|
| Source | Salmon DNA fragments (purified, standardised) | Patient’s own blood |
| Regulatory status | CE-marked Class III medical device | Autologous (own-body) — not regulated as a device |
| Active mechanism | DNA fragments signal fibroblasts to repair and produce collagen / elastin / HA | Platelet-derived growth factors trigger tissue repair |
| Consistency session to session | High — standardised concentration | Variable — depends on patient haematocrit, platelet count, prep technique |
| Procedure time | 15 to 30 min injection | 30 to 45 min (includes blood draw + centrifuge) |
| Course | 3 sessions, 3 weeks apart | 3 sessions, 4 to 6 weeks apart |
| Maintenance | Every 6 to 12 months | Every 6 to 12 months |
| Bruising risk | Moderate (multiple injection points on thin skin) | Moderate (same area + blood draw bruising) |
| Volume effect | None | None |
| Typical course price (London) | £750 (initial 3-session course) | £600–£900 (varies widely) |
What polynucleotides actually do
Polynucleotides are short fragments of DNA — usually sourced from salmon because the molecular size, purity, and immunogenicity profile are favourable. When injected into the dermis, the fragments are recognised by the patient’s fibroblasts (the skin-repair cells) as repair-signalling molecules. The fibroblasts respond by:
- Producing new collagen (structural protein, gives skin firmness)
- Producing new elastin (gives skin recoil)
- Producing new hyaluronic acid (the body’s own hydration molecule)
- Scavenging free radicals in the local tissue environment
The fragments themselves degrade over 3 to 6 weeks, but the new extracellular matrix they trigger persists for months — which is why the visible effect of a 3-session course continues to build for 8 to 12 weeks after the final injection.
Polynucleotides have been used in Korean and Italian aesthetic medicine for over a decade, with the first clinical literature dating to early 2000s. The under-eye area, the neck, the chest, and the scalp are the most commonly treated areas.
What PRP actually does
A typical PRP treatment draws 10 to 20 mL of the patient’s blood into a specialised tube containing an anticoagulant and a separator gel. The tube is spun in a centrifuge for 5 to 10 minutes, separating the heavier red cells (which are discarded) from the lighter plasma containing concentrated platelets. The plasma is then re-injected into the target area.
When platelets are activated by tissue contact, they release growth factors — PDGF, TGF-β, VEGF, EGF, and others — which signal local cells to repair tissue, produce extracellular matrix, and (in some applications) recruit stem cells. The mechanism is the same as the body’s normal wound-healing response, concentrated and delivered to a specific cosmetic site.
The output of any given PRP treatment depends on the patient’s:
- Haematocrit on the day (red cell percentage)
- Platelet count on the day
- Time since last meal, hydration status, and overall haematological state
- Centrifuge protocol the clinic uses (single-spin vs double-spin)
This variability is the central trade-off with PRP — the product is autologous (your own body, lowest possible immunogenic risk) but inconsistent across sessions and across patients.
When to choose polynucleotides over PRP
- The patient wants a standardised, predictable treatment with consistent results session to session
- The patient is needle-phobic and prefers to avoid the blood draw step
- The patient has a bleeding disorder, anticoagulant medication, or recent dental work that complicates blood draw
- The skin concern is primarily textural (fine lines, crepiness, dark circles from skin tone rather than vascular shadowing)
When to choose PRP over polynucleotides
- The patient prefers an autologous treatment (own body, no foreign material at all)
- The patient is treating scalp / hair loss alongside facial concerns (PRP has the stronger published evidence base for androgenetic alopecia)
- Cost is the priority and the clinic’s PRP price is meaningfully lower than its polynucleotides price
The most important point about either
Neither polynucleotides nor PRP restores volume. A patient whose under-eye concern is a deep hollow — visible structural depression below the orbital rim — will not see the hollow fill in with either treatment. The hollow is a volume problem and needs a volume tool (typically tear-trough filler, placed conservatively in the deep medial cheek or pre-periosteal compartment, by a doctor who is comfortable in the area and who carries hyaluronidase on-site).
The right pattern for many patients is:
- Tear-trough filler to address the volume hollow, if the anatomy is appropriate (not every under-eye is filler-suitable)
- Polynucleotides (or PRP) after 4 to 6 weeks to improve the skin quality of the under-eye surface
Treating an under-eye hollow with polynucleotides alone and expecting volume restoration is the under-eye equivalent of treating a wrinkle with filler — using the wrong tool for the job.
Bottom line
Polynucleotides and PRP are both legitimate regenerative tools. The choice between them is less about “which is better” and more about which trade-offs suit the patient — standardised and predictable, or autologous and personal; comfortable with foreign material, or insistent on own-body only; treating skin quality alone, or treating skin quality plus scalp.
Neither one is a volume tool. The under-eye specifically often needs both a volume tool and a regenerative tool, sequenced correctly, by a practitioner whose first instinct is conservative.
