A polynucleotide skin booster is an injectable of purified DNA fragments, usually from salmon, placed in the dermis to support skin repair. PN refers to longer chains and PDRN to shorter fragments, and their products are not interchangeable. Polynucleotides do not hydrate like hyaluronic acid boosters or build structure like collagen biostimulators.
Key facts
- Material
- Purified DNA fragments, usually from salmon, filtered and sterilised
- PN
- Polynucleotide: longer chains that form a viscous gel; Rejuran Healer carries PN at approximately 20 mg/mL
- PDRN
- Polydeoxyribonucleotide: shorter fragments of the same family, used in other preparations
- Described mechanisms
- Adenosine A2A receptor signalling, fibroblast activity and extracellular matrix turnover
- Placement
- Intradermal micro-injection, by fine needle or injector device
- Not directed at
- Volume, lift, pigment or pore diameter
- Discuss first
- Fish or salmon allergy, pregnancy, breastfeeding, autoimmune conditions or a bleeding tendency
What is a polynucleotide skin booster?
A polynucleotide skin booster is an injectable preparation of DNA fragments, extracted and purified, usually from salmon, and placed into the dermis by micro-injection. Purification and sterilisation mean that what is injected is the polymer, not genetic information, which is why searches for 'salmon DNA injection' describe the source rather than what the product does in the skin.
These preparations are directed at the repair environment of the dermis rather than at its bulk. The literature describes two lines of action: signalling through adenosine A2A receptor pathways, which is also how the material's anti-inflammatory effect is described, and an influence on fibroblast activity and extracellular matrix turnover. The long chains also bind water in the tissue they occupy.
Injectable polynucleotides are regulated health products that should be administered by doctors in a clinical setting. Rejuran, made by PharmaResearch in Korea, is registered with Singapore's Health Sciences Authority as an injectable medical device, and it is the polynucleotide booster used at this practice. Rejuran Healer, the standard facial preparation and the product often searched for as 'PN healer', carries polynucleotide at approximately 20 mg/mL.
PN vs PDRN: what is the difference?
PN and PDRN belong to the same molecular family but differ in chain length. PN, polynucleotide, consists of longer DNA chains that form a viscous gel; in Rejuran the chains span a molecular weight range of roughly 50 to 1,500 kDa. PDRN, polydeoxyribonucleotide, consists of shorter fragments. A recent review comparing the two attributes extracellular matrix remodelling mainly to the longer PN chains, and adenosine receptor activation and support for nucleotide synthesis mainly to the shorter PDRN fragments.
The practical point is that the terms are not synonyms. Marketing copy often uses them interchangeably, and searches for a 'PDRN skin booster', 'PN healer' or 'salmon DNA injection' may all describe the same appointment. Products built on each material differ in concentration, viscosity and intended use, and findings reported with one product may not apply to another. It is reasonable to ask which material, and which product, you are being offered.
Other polynucleotide brands, such as Plinest, are used by some clinics. They are separate products from different manufacturers, so a comparison between any two depends on the product information and the evidence for each, not on a shared label. With any injectable, asking for the product name and having it recorded in your notes is sensible.
“Rejuran signals the skin to repair. It does not fill, it does not lift, and it does not remove pigment.”
Dr Sin YongOn what polynucleotides do
How do polynucleotides differ from hyaluronic acid boosters?
Hyaluronic acid boosters work mainly by placing a water-binding molecule into the dermis. Non-cross-linked or lightly bonded hyaluronic acid hydrates where it is put. Profhilo, thermally bonded hybrid hyaluronic acid at 64 mg per 2 mL, spreads through tissue and is designed to stimulate as well as hydrate. The primary intent of the class is hydration and support of the skin envelope.
Polynucleotides have a different primary intent: a repair signal to the dermis. They are directed at complaints where texture, fine lines, elasticity, post-acne skin quality or thin, crepey under-eye skin are the issue, rather than dryness alone. The difference shows on the day, too. Small raised points at the injection sites are expected with both classes, but they tend to be more noticeable at first with polynucleotides.
Rejuran HB combines polynucleotide with hyaluronic acid in one syringe, carrying both a repair signal and a hydrating component. That does not make the two classes interchangeable; it means some skins need both, and the assessment decides the balance. The fuller side-by-side comparison is set out in Profhilo vs Rejuran.
How do polynucleotides differ from collagen biostimulators?
Collagen biostimulators work on structure. Poly-L-lactic acid, polycaprolactone and PDLLA act as a resorbable scaffold that fibroblasts respond to by laying down new collagen over the following weeks and months, which is why they are directed at diffuse volume loss and firmness rather than surface quality. Poly-L-lactic acid and polycaprolactone products also cannot be dissolved, which shapes how they are planned.
A polynucleotide booster has no scaffold. Nothing in the syringe is engineered to occupy space or hold a contour, so it adds no volume and does not lift. A hollow temple or a deflated midface is a structural problem and needs a product designed to stay where it is placed. A crepey, inflamed or textured dermis is a different problem, and that is where a repair signal makes sense. Both classes work gradually through the skin's own response, but they ask different things of it: a biostimulator asks for new structural collagen around a scaffold, while a polynucleotide is directed at the repair environment of the dermis.
The classes are sometimes combined in one plan, because faces often show more than one problem. When they are, the order and spacing are decided at assessment, so that each treatment is given at a sensible point and the reason for each is clear.
Polynucleotides, HA boosters and biostimulators at a glance| Feature | Polynucleotide booster | Hyaluronic acid booster | Collagen biostimulator |
|---|
| Material | Purified DNA fragments, usually salmon-derived; PN longer chains, PDRN shorter | Water-binding hyaluronic acid, such as Profhilo | Resorbable scaffold: poly-L-lactic acid, polycaprolactone or PDLLA |
| Primary intent | A repair signal to the dermis | Hydration and support of the skin envelope | New structural collagen around the scaffold |
| Complaints it suits | Texture, fine lines, elasticity, post-acne quality, crepey under-eyes | Dryness and dehydration | Diffuse volume loss and firmness |
| Volume or lift | None; nothing in the syringe holds a contour | Not volumising | Directed at volume and firmness |
| Time course | Gradual, through the skin's own repair response | Hydrates where it is placed | Collagen laid down over the following weeks and months; cannot be dissolved |
| Who should avoid | Fish or salmon allergy; pregnancy, breastfeeding; active infection | Assessed individually | Assessed individually |
| Combining classes | Order and spacing decided at assessment | Order and spacing decided at assessment | Order and spacing decided at assessment |
Who should avoid polynucleotide boosters?
Anyone with a fish or salmon allergy should raise it with the doctor before any polynucleotide is considered, because the material is fish-derived, and people with that allergy are generally advised to avoid these products. Allergic reaction is rare, but it is the reason the question is asked directly rather than assumed absent.
Injectable polynucleotides are not used in pregnancy or while breastfeeding, and are not injected through active infection or inflamed skin. An autoimmune condition or a bleeding tendency should be discussed with the doctor first, and a keloid tendency is weighed where the intention is to inject into or around scar tissue.
Polynucleotides are also the wrong treatment for some expectations. Anyone hoping for volume, a lift or pigment clearance is being offered the wrong class of product; each of those complaints has its own assessment and its own tools.
Do topical PDRN serums do the same thing?
Not in the same way. Topical PDRN and polynucleotide skincare is sold in Singapore as cosmetic products, but large molecules penetrate intact skin poorly, and the evidence for topical use is weaker than for injection. Salon 'salmon DNA' facials that apply a serum to the surface, sometimes after a device that creates fine channels, are different treatments from an injectable placed into the dermis, and findings from studies of the injectable cannot be transferred to them.
If you are booking a polynucleotide treatment, three questions are worth asking: whether it is the injectable product, whether a doctor is administering it, and which preparation in the range is being used.
After injection, small papules at the injection points, swelling, tenderness and bruising are common and settle as the material is taken up; bruising is more likely around the eyes. Nodules where material sits unevenly, and infection, are less common. Pain that increases rather than settles, spreading redness and warmth, or swelling that does not subside warrants prompt review.
What does the evidence show, and what affects cost?
A systematic review of polynucleotides in aesthetic medicine identified nine studies, of low and moderate quality, reporting improvements in wrinkles, texture and elasticity with generally mild, transient side effects, and concluded that more rigorous, high-quality studies are needed. That is a fair summary of where the field stands: promising, with variation in technique between studies and in response between individuals. Whether a polynucleotide suits your skin is decided by examination under good light and under stretch, which separates texture and crepiness from scarring, pigment and laxity, because only some of those are polynucleotide territory.
Cost depends on the area treated, which preparation the assessment indicates, whether polynucleotides are used alone or alongside other treatment, and how the plan is staged. This site does not publish fees; they are set out at consultation, after the skin has been examined and before anything is agreed. Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh), MSc Aesthetic Medicine with Distinction (Queen Mary, London), MSc Practical Dermatology (Cardiff), assesses and performs injectable treatments personally at Orchard Road.
