PDRN (Polydeoxyribonucleotide)
PDRN — evidence, uses & status

Class: blend
Synonyms: polydeoxyribonucleotide
"salmon DNA"
salmon / trout sperm DNA fragments
PN (polynucleotides)
INCI: sodium DNA / hydrolyzed DNA (cosmetic forms vary)
Function tags: skin appearance (cosmetic)
soothing (appearance)
hydration (appearance)
barrier support
emerging / early evidence
Overall evidence grade: C
WADA prohibited: no
Last updated: 2026-07-20

In brief: PDRN (polydeoxyribonucleotide) is a mixture of DNA fragments, usually derived from salmon or trout, marketed as "salmon DNA" skincare. The honest split: as an INJECTED treatment it is a real, well-studied regenerative compound used in clinical and aesthetic settings — but that is a regulated medical procedure, not a serum. The topical "salmon DNA" products riding that reputation are a much gentler thing: PDRN's large molecules mostly cannot cross the skin barrier, so a serum offers soothing, hydration, and post-procedure comfort rather than the dramatic renewal the injections deliver. That is genuinely nice for sensitive and post-procedure skin, but a world away from the miracle framing. Full deep-dive: the PDRN explainer in the Journal.

## Identity

**PDRN — polydeoxyribonucleotide** — is a mixture of short DNA fragments, most often extracted and purified from salmon or trout (hence the "salmon DNA" nickname). A closely related cosmetic term, **PN (polynucleotides)**, refers to the same family of DNA-fragment ingredients. It is not a single clean molecule but a heterogeneous set of nucleotide chains, which is why this entry files it under a blend rather than one defined compound.

The single most important fact about PDRN is that it lives a **double life**, and the two versions are easy to confuse: an injected regenerative treatment with genuine clinical evidence, and a topical "salmon DNA" serum that borrows that reputation but works far more gently. This entry is a short, graded reference for the cosmetic (topical) use; the full detective breakdown — including the injectable's story — is in the Journal explainer, [the honest guide to PDRN and "salmon DNA" skincare](/learn/what-is-pdrn-skincare).

## Development & history

- PDRN was developed and studied as an **injectable regenerative agent**, with clinical use in wound healing, tissue repair, and, more recently, aesthetic ("salmon DNA") in-office treatments.
- Its proposed mechanism in that setting is twofold: engaging **adenosine A2A receptors** (an anti-inflammatory, pro-repair signal) and supplying **nucleotides** as raw material for cells — a genuine, plausible basis for the injected results.
- Skincare then adapted the name into **topical** serums, where the same molecule faces a very different obstacle: the skin barrier.
- It rose alongside exosomes and stem cells as part of the mid-2020s "regenerative aesthetics" wave — and, like the rest of that wave, the topical marketing runs ahead of the topical evidence.

## Mechanism (as proposed)

Injected PDRN reaches living tissue directly, which is why its regenerative signalling (A2A-receptor activation plus nucleotide salvage) can plausibly drive repair. A **topical** serum does not have that access. PDRN is a **large molecule**, and large polynucleotides do not readily cross the intact **stratum corneum** — so most of the applied dose stays on the surface rather than reaching the fibroblasts that would do any "regenerating."

What a topical PDRN serum *can* honestly do is act as a **humectant and film-forming soothing agent**: it holds water at the surface and feels calming, which is genuinely pleasant for sensitive or post-procedure-feeling skin. That is the supportable claim. The mistake the category invites is crediting the **serum** with the **injectable's** regeneration — two different delivery routes, two different stories. Keep rejuvenation expectations with ingredients that actually reach the deeper skin, and buy topical PDRN for the comfort it really offers.

Evidence grades by outcome:
outcome: Topical cosmetic serum — soothing, hydration, barrier comfort
grade: C
base: Topical PDRN/polynucleotide cosmetics are humectant and film-forming; the supportable benefits are soothing, hydration, and post-procedure comfort — not the regeneration seen with the injectable.
effect: Gentle soothing, hydration, and barrier comfort
caveat: PDRN is a large DNA-fragment molecule that mostly cannot cross the intact stratum corneum, so a topical serum does not deliver the regeneration the injected form does. Benefits are real but modest and comfort-focused.
outcome: Topical "regeneration / rejuvenation" (as marketed for salmon-DNA serums)
grade: D
base: No evidence that a topical serum reproduces injected-PDRN outcomes; penetration of large polynucleotides through intact skin is doubtful.
effect: Not supported for a topical serum
caveat: The serum borrows the reputation of the injected drug. Claims of dramatic renewal from a topical PDRN overstate the evidence and ignore the penetration problem.
outcome: Injected PDRN (clinical / aesthetic, in-office) — for context, NOT cosmetic scope
base: A well-studied regenerative compound as an INJECTED treatment — clinical evidence exists for wound healing, tissue repair, and aesthetic ("salmon DNA") procedures, where it engages adenosine A2A receptors and supplies nucleotides to cells.
effect: Genuine regenerative signalling when injected by a professional
caveat: This is a medical/aesthetic procedure administered by qualified professionals and regulated as a drug or device in many regions — it is out of cosmetic scope, carries procedural risk, and is NOT what a topical serum delivers. Listed only so the two stories are not confused.
outcome: "Collagen-boosting" topical collagen synthesis
grade: D
base: Marketing claim
caveat: The human evidence for this molecule is for the injected form, which reaches the dermis directly and is regulated as a drug or device in some markets — a different route from the one being sold here. No human study shows a topical serum raising collagen synthesis; the topical case rests on reviews of the injected literature and on stratum-corneum permeation arguments, and a 2024 systematic review found the wider regenerative-aesthetics field lacks scientific rigour.

Legal status:
region: INT
status: Cosmetic topical forms sold as skincare; injectable PDRN is a regulated medical treatment
note: Topical PDRN/polynucleotide cosmetics are sold over the counter framed around soothing and hydration. Injected PDRN is a medical/aesthetic procedure regulated as a drug or device depending on region and belongs to qualified professionals. Regulatory context, not a health claim.

Cosmetic claims:
allowed: helps skin feel soothed, calm, and comfortable
provides lightweight hydration and a comforting feel
a gentle option for sensitive or post-procedure-feeling skin
supports the look and feel of a comfortable skin barrier
forbidden: regenerates or renews skin
repairs tissue or wounds
reverses ageing
stimulates collagen or fibroblasts
heals or treats any condition
delivers the results of injectable PDRN

Note: A sellable topical PDRN product is framed around soothing, hydration, and comfort for sensitive or post-procedure-feeling skin — never regeneration or the outcomes of injectable PDRN. The injected/clinical context below is reference background only and is out of cosmetic scope.
Honest note: PDRN's real regenerative evidence is for the INJECTED drug, not the topical serum. Large PDRN molecules mostly cannot cross intact skin, so topical benefits are limited to soothing, hydration, and barrier comfort. Do not credit a serum with the injectable's results.

Sources:
Reviews of PDRN / polynucleotides in regenerative medicine and aesthetics — the substantive evidence base is for INJECTED PDRN (wound healing, tissue repair, aesthetic treatments), not for topical serums.
PRISMA systematic review of regenerative aesthetics covering PDRN alongside exosomes and stem cells (2024) — concluded the field lacks the scientific rigour and regulatory compliance to be considered established.
Dermatological/pharmacology background on stratum-corneum permeability — large polynucleotide molecules do not readily cross intact skin, limiting what a topical serum can deliver.