Glossary · Dr Sin Yong’s protocols

Polynucleotide (PN):
what the term means

Name: Polynucleotide (PN): Meaning | Dr Sin Yong
Creator: Dr Sin Yong
Published: 2026-10-13

Medically reviewed by Dr Sin Yong · Last reviewed 8 November 2026 · 3 min read

How a polynucleotide course is quoted is covered on Rejuran Singapore price.

The standard facial polynucleotide preparation is described on Rejuran Healer Singapore.

Main guide Rejuran Singapore — what it treats, who it suits, sessions, downtime and what decides the cost, by Dr Sin Yong.

Published 13 October 2026 · Reviewed by Dr Sin Yong

Abstract still life of glass ampoules and droplets in soft light, illustrative

Polynucleotide (PN) is the term for long chains of nucleotides purified from salmon DNA, filtered and sterilised so that what is injected is the polymer, not genetic information, and placed in the dermis as a skin booster to support how the skin repairs itself. Polynucleotide is the material in Rejuran, at roughly 20 mg/mL in Rejuran Healer. It adds no volume, does not lift and does not remove pigment.

Key facts

Material: Nucleotide chains across roughly 50–1,500 kDa, purified from salmon DNA
Product: Rejuran (PharmaResearch, Korea), registered with Singapore’s HSA as an injectable medical device
PN vs PDRN: PN is the longer-chain material; PDRN (polydeoxyribonucleotide) is shorter fragments of the same family. Products built on each are not the same
Not: A filler: no volume, no lift, no action on pigment; fish allergy is checked first

A woman in her twenties with fresh skin and a towel headband (illustrative image, not a patient) — Illustrative image, not a patient.

Where polynucleotides matter on this site

Polynucleotide is the material behind most of the skin-repair injections on this site, and the pages below are where it is chosen, combined or ruled out.

Polynucleotide is for skin that needs to repair itself; it is not a way to replace volume or lift a face.— Dr Sin Yong

Rejuran: the range explained, Healer, S, I and HB, and what each is directed at.
Rejuran I: under-eye skin quality, and why it is not a tear trough filler.
Rejuran S: the scar formulation, and where it sits within a scar programme.
Skin boosters with RF microneedling: why the two are combined, which goes first and how the spacing is decided.
PRP vs polynucleotides for hair: the scalp use, with the evidence for each set out honestly.

Regulatory status. Rejuran is registered with Singapore's Health Sciences Authority as an injectable medical device and is administered by a doctor. Topical PN and PDRN serums are a different category: cosmetic products notified to the HSA under the Health Products Act.

Not to be confused with

Polynucleotides sit in a crowded category, and several neighbours are marketed with the same words.

PDRN. Polydeoxyribonucleotide, shorter fragments of the same family. Products built on PN and on PDRN are not the same, even when the terms are used interchangeably.
Hyaluronic acid skin boosters. Profhilo and similar products hydrate and support the dermis through hyaluronic acid; the Profhilo vs Rejuran guide sets out which skin suits which.
Exosomes. Cell-released vesicles used topically after a procedure in Singapore, not injected. For injected regenerative support, the site's position is that the evidence currently favours polynucleotides.
Collagen biostimulators. Particles that provoke a collagen scaffold and cannot be dissolved; polynucleotide adds no particle and no volume.

On a treatment menu these often appear side by side as "boosters". The question that separates them is what each is directed at: hydration, repair, collagen or volume. A plan that cannot answer that has not yet been made.

What decides whether polynucleotides matter for you

The first decision is whether the problem is skin quality or structure, because polynucleotide only answers the first.

Skin or structure? Thin, dull, post-acne or crepey skin suits it. A hollow, descent or heavy laxity needs a different material or an energy treatment.
Fish or salmon allergy. This rules it out, because the material is purified from salmon DNA, and it is asked about first.
Under the eye. Crepey under-eye skin is a Rejuran I question; a hollow or a true bag is not, and the eye bags, dark circles or tear trough check explains the difference.
Scars and texture. Polynucleotide is a support step within a scar plan, often alongside resurfacing or RF microneedling, rather than a scar treatment on its own.

Dr Sin Yong decides between skin and structure at an in-person assessment, and often combines a booster with a device session rather than offering either alone.

A lump after a skin booster that has not settled, and only offered surgery? Get assessed first: cutting it out leaves a scar. Find out how Dr Sin Yong treats skin booster lumps without surgery.

Where it fits

Polynucleotide is the injected regenerative material Dr Sin Yong reaches for when the problem is skin quality rather than structure: thin, dull or post-acne skin, under-eye crepiness and the texture left after acne. The Rejuran page explains how he decides between skin and structure, and why he often pairs it with a resurfacing or RF microneedling session. The shorter-fragment relative is set out on PDRN / polynucleotides, and the scar formulation is Rejuran S. Where topical exosomes are marketed for the same purpose, the site notes that for injected regenerative support the evidence currently favours polynucleotides. The wider category is defined under skin booster.

Frequently Asked Questions

Anyone with a fish or salmon allergy, since the material is purified from salmon DNA. Polynucleotide is also not the answer when the problem is a hollow, descent or heavy laxity, because it adds no volume and does not lift. Active infection or inflammation in the treatment area is settled first. Suitability is decided at an in-person assessment, where the alternatives are discussed alongside it.

No. Topical PN and PDRN serums are cosmetic products in Singapore, applied to the surface and notified to the HSA as cosmetics. Rejuran is an injectable medical device placed into the dermis by a doctor. The two differ in route, regulation and evidence, so a serum is not a substitute for the injected treatment, and the injected treatment is not needed for every skin concern.

No, though the two are often used interchangeably. PN denotes the longer-chain polynucleotide in the Rejuran range; PDRN denotes polydeoxyribonucleotide, shorter fragments of the same family used in other preparations. Products built on each differ.

No. It is directed at how the skin repairs itself, not at volume, lift or pigment. Where a hollow or descent is the problem, a different material or an energy treatment is planned instead.

Polynucleotide (PN):what the term means