How Rejuran (PDRN / Polynucleotide) Actually Works: The Mechanism Explained (Complete Guide) | Korean Plastic Surgery

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Medical review & disclaimer — Prepared by the Korean Plastic Surgery editorial team in consultation with KHIDI-registered Korean dermatology clinics and peer-reviewed literature. This is general information, not a substitute for an in-person consultation with a licensed dermatologist.

Rejuran is an injectable skin booster made of polynucleotides (often labelled PDRN) — short DNA fragments purified from salmon — that are micro-injected into the skin to support its own repair signaling, hydration and collagen-friendly conditions, rather than to add volume the way a filler does.

Most marketing copy lumps Rejuran in with fillers or simply calls it "salmon DNA." This guide explains the actual proposed mechanism, separates what the evidence supports from what it does not, and sets realistic expectations for international patients considering treatment in Korea.

What PDRN and Polynucleotides Actually Are

Polynucleotides are chains of nucleotides — the same building blocks that make up DNA. PDRN (polydeoxyribonucleotide) is a specific, purified, fragmented form. In products like Rejuran the material is extracted from salmon or trout milt and processed to remove proteins that could trigger an immune reaction.

Because the molecule is a biological signaling material rather than a space-filling gel, it is classified and used differently from hyaluronic-acid fillers. Understanding this distinction is the key to setting correct expectations.

The Proposed Mechanism: Repair Signaling, Not Filler Volume

The leading proposed mechanism is that PDRN engages adenosine A2A receptors and supplies nucleotides through a salvage pathway, which together are thought to support fibroblast activity, modulate inflammation and encourage the skin's own collagen and extracellular-matrix production over weeks.

Practically, that means Rejuran is aimed at gradually improving skin quality — elasticity, fine texture, hydration — rather than instantly plumping a line. Results build over a course of sessions, which is the opposite of the immediate effect patients expect from filler.

What the Evidence Does and Doesn't Show

Several small clinical studies and reviews report improvements in skin elasticity, hydration and patient satisfaction, and PDRN has a long history of use in wound healing. The overall evidence base, however, is made up largely of small trials, and effect sizes and durability vary between studies.

An honest summary is that the mechanism is biologically plausible and short-term skin-quality benefits are reported, but high-quality, large, long-term trials remain limited. Claims of dramatic or permanent transformation are not supported by current data.

Rejuran vs. Skin Boosters vs. Filler

Hyaluronic-acid "skin boosters" (such as some Juvelook or Profhilo protocols) primarily add hydration and a bio-remodelling effect; fillers add structural volume; Rejuran is positioned as a repair-signaling booster. Many Korean clinics combine modalities across separate sessions rather than treating them as competitors.

If your goal is volume or a sharper contour, a booster is the wrong tool. If your goal is gradual skin-quality improvement, Rejuran-type treatments are designed for that lane.

Typical Protocol and What to Expect

A common starting protocol is a short series of sessions (often three to four) spaced two to four weeks apart, followed by periodic maintenance. The injections are superficial and numbing cream is usual; transient bumps, redness or bruising for a few days are expected.

Visible change is gradual and best judged a few weeks after completing the initial series. Ask your clinic to document baseline photos so improvement can be assessed honestly rather than from memory.

Safety, Side Effects, and Who Should Wait

Common side effects are injection-site redness, swelling, small papules and bruising that typically settle within days. Because the source material is fish-derived, anyone with a known fish allergy should disclose it; pregnancy, active skin infection at the site, and certain immune conditions are typical reasons to defer.

As with any injectable, choose a licensed clinic, confirm the product is genuine and properly stored, and treat any "guaranteed" result claim as a red flag rather than reassurance.

Frequently Asked Questions

How many Rejuran sessions will I need?

A typical initial course is three to four sessions spaced two to four weeks apart, then occasional maintenance. Your dermatologist will tailor this to your skin and goals.

Is there downtime, and does it hurt?

Numbing cream is standard; most people have only minor redness, small bumps or bruising for a few days. Plan a few days before events.

Is the effect permanent?

No. Effects build over a session course and then gradually fade, which is why maintenance is recommended. Current evidence does not support permanent results.

I'm allergic to fish — can I have Rejuran?

Tell your clinician first. Because the material is salmon-derived, a known fish allergy is a reason for caution and may make treatment unsuitable.

Sources

This guide draws on the following primary sources. Always verify medical claims against peer-reviewed literature and official institutions:

PubMed: polydeoxyribonucleotide (PDRN) skin and wound healing · KHIDI — Medical Korea · Korean Dermatological Association

Last medically reviewed

Last medically reviewed: 2026-06-14 by the Korean Plastic Surgery editorial team in consultation with Korean dermatology specialist sources. This content is general information and does not replace individual medical advice.

Curious whether a skin booster suits your skin? Request a free assessment from certified Korean dermatology clinics.