Medically reviewed by Dr Sin Yong · Last reviewed · 19 min read · Doctor-performed, never delegated · Jump to questions
Dr Sin Yong · MBBS (NUS) · MRCS (Edin) · MSc Aesthetic Medicine with Distinction (Queen Mary, London) · MSc Practical Dermatology (Cardiff) · International KOL
A polynucleotide preparation purified from salmon DNA, delivered by intradermal micro-injection. It is directed at how the skin repairs itself — not at volume, not at lift, not at pigment.
Rejuran Healer is a polynucleotide skin booster purified from salmon DNA and registered with Singapore's Health Sciences Authority as an injectable medical device. It is injected into the dermis to support skin repair, texture and elasticity. It is not a filler: it adds no volume, does not lift and does not remove pigment. Fish allergy is checked first.
Also called: polynucleotide (PN) injections, 婴儿针, リジュラン
Rejuran is made by PharmaResearch in Korea and is registered with Singapore’s Health Sciences Authority as an injectable medical device. The active material is polynucleotide — chains of nucleotides purified from salmon DNA, filtered and sterilised so that what is injected is the polymer, not genetic information. Rejuran Healer carries polynucleotide at approximately 20 mg/mL, around 2 per cent.
Two terms get used interchangeably and should not be. PN denotes polynucleotide, the longer-chain material in the Rejuran range. PDRN denotes polydeoxyribonucleotide, shorter fragments of the same family used in other preparations. Products built on each are not the same product, and a page that treats the two as synonyms is describing something else.
It is not a filler. Nothing in the syringe is engineered to occupy space or hold a contour. What is being bought is a signal to the tissue, delivered where the tissue can act on it.
“Nobody is injecting fish into your face. Here is what is actually in the syringe. Purified DNA fragments.”
Dr Sin YongOn what polynucleotides are · from his Instagram explainer series
Polynucleotides act on the repair environment of the dermis rather than on its bulk. Two effects are described in the literature: an influence on fibroblast activity and extracellular matrix turnover, and signalling through adenosine A2A receptor pathways, which is also the route through which the molecule’s anti-inflammatory action is described. The material additionally behaves as a hydrophilic polymer in the tissue it occupies.
The practical consequence is that Rejuran is directed at how skin behaves rather than at how much of it there is. It changes no dimension of the face, and tissue that is signalled to repair still has to do the repairing.
“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
Rejuran Healer is the standard facial preparation, polynucleotide at approximately 20 mg/mL, injected intradermally across the face.
Rejuran S is formulated at a higher viscosity and is intended for scarred skin, where the material is placed into and around the scar rather than spread across a field — one component of a wider approach to acne scarring.
Rejuran I is lower in viscosity, intended for the thin skin of the periorbital area. Under-eye complaints are frequently not skin complaints at all: hollowing, shadow and herniated fat all present as “dark circles” — distinctions set out in the under-eye filler guide and under tear trough refinement. Which a face has is decided by examination, not by product choice.
Rejuran HB combines polynucleotide with hyaluronic acid, so it carries both a repair signal and a hydrating component in one syringe.
Rejuran is directed at skin texture, fine lines, elasticity, the quality of post-acne skin and the appearance of enlarged pores — dermal-quality complaints, the territory where a repair signal is a sensible thing to deliver.
It adds no volume. A hollow or a deficient contour is a structural problem and needs material engineered to stay where it is put. No polynucleotide preparation does that.
It does not remove pigment. Melasma, sun-induced marks and post-inflammatory hyperpigmentation are chromophore problems, addressed by light-based and topical approaches.
It does not shrink pores. Nothing shrinks a pore — a pore is a fixed anatomical opening. What changes is how strongly it contrasts with the skin around it, which is a question of surface texture and dermal support, and that is what a repair signal can address.
Because the material is purified from salmon DNA, fish allergy is asked about and assessed before anything is offered. It is not used in pregnancy or while breastfeeding, not injected through active infection or inflamed skin, and a keloid tendency is weighed where the intention is to inject into or around scarred tissue. Anyone expecting volume, a lift or pigment clearance is being offered the wrong treatment.
Examination looks at the skin under good light and under stretch. Post-acne skin has to be sorted: rolling scars tethered to the dermis, boxcar scars with a fixed wall, ice-pick tracts, and residual redness or pigment that is not scarring at all. Those are treated differently, and a polynucleotide addresses the skin-quality component. Nothing here substitutes for that examination.
Topical anaesthetic is usual. Delivery is by fine needle in a distributed pattern of micro-injections, or by an injector device placing small volumes at a set depth; which is used depends on the area. Small papules or wheals appear at the injection points as the material sits — the expected appearance, not a complication. The plan and any intervals are set individually at review rather than quoted in advance.
Recovery varies. The papules settle as the material is taken up; bruising is possible, particularly around the eyes where skin is thin and vessels superficial. What warrants prompt review rather than waiting: pain that increases instead of settling, spreading redness and warmth, or swelling that does not subside. Between visits a plain barrier-supporting routine such as weekly maintenance is usually all that is asked for.
The common events are local: bruising, swelling and tenderness at the injection points, and visible papules that settle. Nodules can occur where material is deposited unevenly or too superficially, and infection is uncommon but possible with any needle through skin.
Allergic reaction is rare, but it is the reason fish allergy is asked about directly rather than assumed absent. Where injection is in or around scar tissue, a personal or family history of keloid formation is weighed before proceeding.
Profhilo. Profhilo is hyaluronic acid — 64 mg per 2 mL, thermally bonded hybrid complexes that disperse through tissue. A different molecule, acting on hydration and the skin envelope.
Hyaluronic acid skin boosters place non-cross-linked or lightly bonded HA intradermally to hydrate where it is put. See skin boosters for how the classes separate.
PDLLA biostimulators. Poly-D,L-lactic acid acts as a resorbable scaffold recruiting the patient’s own collagen over a longer arc — a structural intention rather than a skin-quality one. See collagen biostimulators.
Pico laser. Picosecond laser works photoacoustically on pigment particles and on focal dermal injury. It addresses a chromophore; an injectable does not.
Ablative CO2 resurfacing removes columns of tissue so the wall of a structural scar is remodelled. Where a scar is tethered or has a fixed edge, signalling the skin to repair will not lift it — that is resurfacing or subcision territory, under acne scar treatment.
Treatment is planned individually, so cost follows the plan rather than a published list.
A figure quoted before examination would not reflect your presentation. Cost is set out at consultation, before anything is agreed.
Rejuran is generally well tolerated when it is injected by a doctor after assessment, but like any injectable it carries risks that should be stated before treatment. It is registered with Singapore's Health Sciences Authority as a medical device, and the polynucleotide is purified and sterilised from salmon DNA so that what is injected is the polymer, not genetic material.
The common effects are local and expected: small papules at the injection points, swelling, tenderness and bruising, more so around the eyes. Less common are nodules where material sits unevenly or too superficially, and infection. Allergic reaction is rare, which is why fish allergy is asked about directly rather than assumed absent.
Safety also depends on who is treated. Rejuran is not used in pregnancy or while breastfeeding, or through active infection or inflamed skin, and a keloid tendency is weighed before injecting near scars. It is given with sterile technique by a doctor; a product of uncertain origin, or injection outside a medical setting, removes the safeguards that make the treatment predictable.
A 'Rejuran facial' usually means Rejuran Healer injections, not a facial in the spa sense. The name has stuck because the treatment covers the whole face and is often booked as regular skin maintenance, but the product works only because it is placed into the dermis by micro-injection, which in Singapore is a medical treatment performed by a doctor.
Some salons offer facials with polynucleotide or 'salmon DNA' serums applied to the surface, sometimes after a device that creates fine channels. These are different treatments: a topical serum does not deliver the same material to the same depth, and findings from studies of the injectable cannot be transferred to it.
If you are booking a Rejuran facial, it is worth confirming three things: that it is the injectable product, that a doctor is administering it, and which preparation in the range is being used. The visit itself, the papules that follow and the recovery are described above.
| Option | What it does | What it cannot do | Typical recovery | Who it tends to suit |
|---|---|---|---|---|
| Rejuran Healer | Standard facial preparation: polynucleotide at about 20 mg/mL placed intradermally across the face | Add volume, lift or clear pigment | Small papules at the injection points that settle; bruising possible | Texture, fine lines, elasticity and overall skin quality on the face |
| Rejuran S | Higher-viscosity preparation placed into and around scars | Release a tethered scar or resurface a fixed-wall scar | Papules and possible bruising over the treated scars | The skin-quality component of acne scarring, alongside structural scar work |
| Rejuran I | Lower-viscosity preparation for the thin periorbital skin | Correct hollowing, shadow or herniated fat under the eyes | Bruising is more likely around the eyes | Fine lines and crepey skin around the eyes, once the under-eye cause is diagnosed |
| Rejuran HB | Polynucleotide combined with hyaluronic acid in one syringe | Replace a filler or a structural treatment | Papules that settle; bruising possible | Skin that needs both a repair signal and hydration |
The sequence below describes phases, not a timetable: how quickly each passes depends on the settings used, the area and the person, and is discussed at consultation.
People expecting volume, a lift, pigment clearance or smaller pores tend to respond poorly, because Rejuran is directed at skin quality only.
The fee depends on the area treated, which Rejuran product suits the skin (Healer, S, I or HB), the amount used, whether needle or injector device delivery is chosen, and whether it is combined with another treatment. A written quote is given at consultation, after Dr Sin Yong has examined the skin. The consultation also decides whether Rejuran is advised at all, or whether the concern, such as volume or pigment, needs a different treatment.
How quotes work at this practice: how we quote.
It adds no volume and does not lift; it is a polynucleotide directed at how skin behaves, not how much of it there is.
A pore is a fixed opening and pigment is a chromophore problem; Rejuran addresses texture and dermal support only.
Rejuran is a polynucleotide preparation made by PharmaResearch in Korea and registered with Singapore’s Health Sciences Authority as an injectable medical device. The polynucleotide is purified and sterilised from salmon DNA, with chain lengths spanning roughly 50–1,500 kDa. Rejuran Healer carries it at approximately 20 mg/mL, around 2 per cent.
No. Nothing in the range is engineered to occupy space or hold a contour, and none of it corrects a structural deficit. Rejuran is directed at the repair environment of the dermis — fibroblast activity, matrix turnover and inflammatory signalling. A hollow or a deficient jawline needs material designed to stay where it is placed, which is a different class of product entirely.
PN means polynucleotide, the longer-chain material used in the Rejuran range. PDRN means polydeoxyribonucleotide, shorter fragments of the same molecular family used in other preparations. The two terms are often treated as interchangeable in marketing copy, but the products built on each are not the same, and the distinction is worth asking about directly.
Healer is the standard facial preparation. S is formulated at a higher viscosity for scarred skin, where material is placed into and around the scar rather than spread across a field. I is lower in viscosity and intended for the thin skin of the periorbital area. HB combines polynucleotide with hyaluronic acid. Which is appropriate is decided at examination.
Post-acne skin contains several different things: rolling scars tethered to the dermis, boxcar scars with a fixed wall, ice-pick tracts, and residual redness or pigment that is not scarring at all. A polynucleotide addresses the skin-quality component. A tethered or fixed-wall scar is a structural problem and needs structural work — subcision or resurfacing — alongside it.
Nothing shrinks a pore. A pore is a fixed anatomical opening, and no injectable, laser or topical closes it. What changes is how strongly a pore contrasts with the skin around it, which depends on surface texture and on dermal support beneath. That contrast is what a repair signal delivered into the dermis can act on.
The plan, the preparation used and any interval between visits are set individually at review, after the skin has been examined and its response assessed. No standard course is quoted here, because appropriate staging depends on the area treated, what the skin is doing, and whether structural work is being planned alongside the injectable.
Recovery varies. Small papules or wheals appear at the injection points and settle as the material is taken up; bruising is possible, particularly around the eyes where skin is thin. Nodules and infection are uncommon; allergic reaction is rare. Increasing pain, spreading redness and warmth, or swelling that does not subside warrant prompt review rather than waiting.
Fish allergy is asked about and assessed before anything is offered, because the polynucleotide is purified from salmon DNA. It is not used in pregnancy or while breastfeeding, and not injected through active infection or inflamed skin. A keloid tendency is weighed where the intention is to inject into or around scar tissue. Anyone expecting volume, lift or pigment clearance is being offered the wrong treatment.
Topical anaesthetic is usually applied first, and most people describe a series of small pricks with some stinging as the material is placed. The skin around the eyes and over scars tends to be more sensitive. Comfort is checked during treatment, and delivery by fine needle or injector device is chosen according to the area.
Yes, and for post-acne skin it often should be, because a polynucleotide addresses skin quality while tethered or fixed-wall scars need subcision or resurfacing. Rejuran can also sit alongside pigment treatment, or a filler for a separate structural problem. The order and spacing are decided at assessment so that each treatment is given at a sensible point in healing.
The fee depends on the area treated, which Rejuran product suits the skin, the amount used, the delivery method and whether it is combined with another treatment. A written quote is given at consultation, after Dr Sin Yong has examined the skin. No price is set beforehand, and the consultation decides whether Rejuran is advised at all.
It is worth considering for skin texture, fine lines, elasticity or post-acne skin quality, where a repair signal to the dermis is a sensible approach. It is a poorer fit for anyone expecting volume, lift, pigment clearance or smaller pores, because it does none of these, or anyone allergic to fish.
No duration can be promised. How long skin quality stays improved depends on your skin, age, sun exposure, skincare, the product used and the area treated, since tissue that is signalled to repair still has to do the repairing. Intervals and review timing are set individually at consultation.
It involves multiple micro-injections, so papules, bruising and swelling are expected, and nodules or infection can occur. It adds no volume, lift or pigment change and is not used in pregnancy or with fish allergy. A plan is built over visits, and change varies between individuals.
Available on Orchard Road, Singapore. By appointment with Dr Sin Yong.
Rejuran is a polynucleotide injectable used in Singapore, directed at skin texture, fine lines, elasticity and the quality of post-acne skin. It is not a filler and adds no volume.
Medically reviewed by Dr Sin Yong, MBBS (NUS), MRCS (Edinburgh) · Last updated 20 September 2026 · Editorial policy
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