Walk into any aesthetic clinic in Seoul, scroll any beauty TikTok, or read any K-beauty product label, and you will find three terms used almost interchangeably: PDRN, polynucleotides, and salmon DNA. They sound related — and they are — but they are not the same thing. The differences matter for your wallet, your routine, and your expectations.
The short answer
- Salmon DNA — the raw source material. Whole DNA strands extracted from salmon (or salmon trout) sperm.
- Polynucleotides (PN) — longer, partially fragmented DNA chains derived from salmon DNA. Used mostly in clinical injectables for deep structural rejuvenation.
- PDRN — short, highly purified DNA fragments derived from salmon DNA. Used in both injectables (lighter rejuvenation) and topical skincare.
Think of it as a spectrum of molecular size: salmon DNA is the long version, polynucleotides are the medium version, PDRN is the short version. Each behaves differently on contact with your skin.
Salmon DNA: the broad term
“Salmon DNA” is often used loosely on Korean product labels to mean “contains some form of fish-sourced DNA material.” It is a marketing-friendly umbrella term. Salmon DNA itself, in its full-length form, is too large to penetrate skin topically — so when you see it on a label without further specification, the product is usually relying on smaller-molecule technology underneath. Treat it as a starting clue, not a finished claim.
Polynucleotides: the deep rejuvenator
Polynucleotides (PN or PNs) are longer DNA chains, partially fragmented but still substantial. Their primary use is in injectable biostimulators — brand names like Plinest, Newest, and Croma Pharma’s offerings. PNs build the structural matrix of the skin: hydration, dermal density, collagen architecture. They are typically used by aesthetic clinicians as an alternative to traditional hyaluronic acid fillers, with a different feel and longer-developing effect.
PN treatments are clinic-only — there are no meaningful topical PN products, because the molecules are too large for skin penetration.
PDRN: the versatile one
PDRN — polydeoxyribonucleotide — is the short-fragment version. Small enough to be formulated into topical serums that achieve meaningful penetration (especially with modern delivery tech), and short enough to bind cleanly to the adenosine A2A receptor that triggers fibroblast activity. That is why PDRN is the only one of the three with a real consumer skincare presence.
Injectable PDRN — like Rejuran Healer — delivers a higher dose for clinical-grade results. Topical PDRN — like the serums in our 2026 ranking — is the at-home version with subtler, cumulative effects.
So which should you buy?
- Topical skincare: Look specifically for PDRN on the label. If a product just says “salmon DNA” without specifying molecular weight or PDRN content, it is probably a weaker formulation.
- Clinical injectables for fine lines and texture: PDRN (e.g. Rejuran Healer) is the right ask.
- Clinical injectables for deep structural rejuvenation: Polynucleotides (e.g. Plinest) are the right ask — but expect a different result and a different price tier.
What labels lie about
Watch for two common moves: (1) products that prominently say “DNA” or “salmon DNA” without disclosing whether they actually contain PDRN, and (2) products that list PDRN at the bottom of the ingredient list, meaning trace amounts. Real PDRN serums disclose concentration or at least list the ingredient high in the formula. Brand transparency separates serious formulations from marketing exercises.
