What is Rejuran?
Rejuran is a polynucleotide skin booster made by PharmaResearch in Korea. It is registered with Singapore's Health Sciences Authority as an injectable medical device, and a doctor places it in the dermis. The polynucleotide is purified from salmon DNA.
It is not a filler. It adds no structural volume, does not lift and does not remove pigment. It is said to act on skin repair signalling, so the aim is texture and quality, not a different shape. Change builds gradually over a course, and the course itself is set for you.
Two points cause confusion. First, shop-sold Rejuran creams and ampoules are cosmetics that sit on the surface, and they are not the same as the injected treatment. Second, polynucleotide (PN) and polydeoxyribonucleotide (PDRN) are not the same product. PN is the longer-chain material, and PDRN refers to the shorter fragments used in other preparations. If a product name is unclear, ask exactly what is being injected. Nicknames in this field are used loosely.
How does polynucleotide act in the dermis?
Polynucleotide targets the repair environment of the dermis, not its bulk. Dr Sin Yong places it as many tiny deposits. The aim is a signal to fibroblasts, the cells that make skin structure. Nothing in the syringe is built to take up space, so the target is how the skin behaves and not the shape of the face.
A 2025 review sets out how the molecules are thought to differ. It links the longer DNA chains in PN mainly to remodelling of the extracellular matrix, the framework around skin cells, and the shorter fragments in PDRN mainly to adenosine receptor activation. [2] This is a review of mechanisms, not a treatment trial, so it cannot tell you how your own skin will respond.
The skin still has to carry out the repair itself, which is why any change is gradual and results vary. Other injectables do different jobs, and the skin booster guide sets out which class fits what the skin lacks.
What is the difference between Rejuran Healer, S, I and HB?
| Preparation | What it is | Tends to suit | Cannot do |
|---|---|---|---|
| Healer | Standard facial preparation, placed intradermally across the face | Texture, fine lines, elasticity and overall skin quality | Add volume, lift or clear pigment |
| S | Higher-viscosity preparation placed into and around scars | The skin-quality part of acne scarring, alongside structural scar work | Release a tethered scar or resurface a fixed-wall scar |
| I | Lower-viscosity preparation for thin skin around the eyes | Fine lines and crepey skin, once the under-eye cause is diagnosed | Correct hollowing, shadow or fat that has moved forward |
| HB | Polynucleotide with hyaluronic acid in one syringe | Skin that needs a repair signal and hydration | Replace a filler or a structural treatment |
Who is Rejuran suitable for?
Rejuran tends to suit people concerned with texture, fine lines, reduced elasticity or tired-looking skin quality. It also fits post-acne skin quality as one part of a wider plan. Which preparation you have is decided at examination, not by product preference. Men are assessed the same way, and there is no set age. If you are hoping for volume, a lift, clearer pigment or smaller pores, this is the wrong treatment, and it is better to know that first. A Rejuran facial needs a licensed medical clinic, as a doctor must place the material in the dermis. Salon serums applied to the surface are a different treatment, even when the name sounds similar. Rejuran can be considered for dullness, thin or sensitised skin, fine texture and shallow scarring. It is not suited to sagging, deep lines or volume loss. Rejuran is used across skin types, including Asian skin, and suitability is judged by your skin and history, not by your age or a preference for one brand.
Fish allergy and who should wait
Fish allergy is checked first. Because the material is purified from salmon DNA, a fish or salmon allergy is a reason to assess carefully or choose a different skin booster. Allergic reaction is rare, but fish allergy is still asked about directly rather than assumed absent.
Pregnancy or breastfeeding. Active infection or inflamed skin at the injection site.
A keloid tendency where injecting in or around scars. Blood-thinning medicines or a bleeding tendency. Allergy to topical anaesthetic.
Volume loss or hollowing, melasma or pigmentation, and tethered or fixed-wall scars need a structural, light-based or scar plan, instead of or alongside the injectable.
Rejuran or Profhilo: which fits?
| Rejuran | Profhilo | |
|---|---|---|
| Material | Polynucleotides from salmon DNA | Hybrid hyaluronic acid, without chemical crosslinkers |
| Main purpose | Repair signalling and texture | Hydration and the skin envelope |
| Placement | Many fine deposits in the dermis | A small number of injection points per side |
| Tends to suit | Damaged, textured or sensitive skin, thin under-eye skin, and scars as part of a plan | Dehydrated, dull, crepey skin. The more usual choice for the neck |
| Visible after | Pinpoint marks or papules at each point | Bumps at injection points |
| Precaution | Fish or salmon allergy | Allergy to HA or a component |
| Neither can | Add volume, lift a cheek or define a chin | Add volume, lift a cheek or define a chin |
The short answer on choosing
Choose according to what your skin lacks. If it is mainly dehydrated and dull, Profhilo fits the brief. If it is mainly damaged, textured or sensitive, Rejuran fits. If you need both, they can be used together, but they are sequenced and not given in one sitting. Combining them means two full protocols, so it is sensible to rank what matters most and start there. Rejuran is also the one more often considered for acne scars, using the thicker S preparation. Neither replaces a lifting treatment. Laxity beyond a certain point is an energy-based question, and no skin injectable substitutes for that. An in-person assessment with Dr Sin Yong settles the choice, and no treatment may also be the right answer.
What it cannot do
Hollows need a structural plan, such as fillers.
Sagging is assessed for energy-based lifting or other options.
Melasma, sun marks and post-inflammatory marks need a different plan.
Pore size does not change with this injection.
Under-eye hollows and shadow need the cause diagnosed first. See tear trough care.
Tethered or fixed-wall scars need subcision or resurfacing alongside it.
Is needle-free Rejuran the same as the injection?
No. A product on the skin surface is a different treatment from an injection into the dermis, even when the names sound alike. Ask how the product reaches the skin and who gives it. Findings from studies of the injection cannot be carried over to surface products.
| Option | How it is given | Where it fits |
|---|---|---|
| Rejuran injection | Placed in the dermis by micro-injection, by a doctor | The treatment on this page |
| Polynucleotide or salmon DNA serum | Applied to the surface, sometimes after a device that makes fine channels | A separate treatment that does not place the same material at the same depth |
| Topical exosomes | Applied straight after fractional laser or RF microneedling; not injected here | An add-on to that procedure. See the exosome guide |
| Deep Synergy Booster | Needle-free; actives delivered using focused ultrasound | A separate hydration step, not a polynucleotide injection |
Can Rejuran be combined with laser or RF microneedling?
Yes. Rejuran can sit in one plan with treatments that do a different job, and the order matters. Dr Sin Yong sets the order and spacing at assessment, so that each treatment can be judged before the next is added. Scar plans belong to acne scar treatment.
| Paired with | Its job in the plan | How timing is set |
|---|---|---|
| RF microneedling | Targets the dermis at a chosen depth, for texture, pores and some scars | Usually first, with the booster placed into settled skin at review |
| Subcision | Releasing a tethered scar | Before any booster |
| Resurfacing | Fixed-wall scars, which a booster cannot reach | The depth left after subcision decides the next step |
| Pigment treatment | Melasma and sun marks, which Rejuran does not target | Set at assessment |
| Filler | A separate structural problem, such as a hollow | A recent filler in the same area is a reason to wait |
| Profhilo | Hydration and the skin envelope | Sequenced, not given in one sitting |
How Dr Sin Yong approaches Rejuran
Dr Sin Yong assesses the skin and gives the injections himself. His opening question is whether the problem lies in the skin or in the structure beneath it.
He looks at the skin in good light and under stretch. Post-acne skin is sorted into rolling scars, boxcar scars, ice-pick tracts and leftover redness or pigment, because polynucleotide reaches only the skin-quality part. He asks what has been injected before, and uses ultrasound where that history includes filler.
He says no when the goal is one the product cannot meet: volume, a lift, pigment clearance or smaller pores. He says so plainly when a hollow, a dropped contour or a tethered scar needs a structural plan instead. No booster is offered for dark circles that turn out to be hollowing, shadow or fat.
A recent laser, peel, filler or thread in the same area means waiting, so that each treatment can be judged on its own. Earlier filler in the planned area is mapped first. A fish or salmon allergy is a reason to choose a different skin booster, and any history of severe allergy is talked through before anything is offered.
A tethered scar is released by subcision before any booster goes in, and the depth left behind decides the next step. For post-acne skin he often pairs the injectable with resurfacing or RF microneedling, since polynucleotide alone addresses skin quality.
“Rejuran signals the skin to repair. It does not fill, it does not lift, and it does not remove pigment.”
How should I prepare for Rejuran?
Preparing is mostly about telling the clinic what it needs to know, and choosing a day that allows for the bumps.
What happens during a Rejuran treatment?
What is normal after Rejuran, and what is not?
Small bumps at each injection point are expected. They flatten as the polynucleotide is taken up, and how quickly depends on the area and on you. Anything that gets worse instead of settling needs action.
| What you notice | What it may mean | What to do |
|---|---|---|
| Small raised bumps at each point | Expected: material sitting in the dermis | Leave them alone. No make-up until the points have closed |
| Redness and warmth on the day | Expected: from the needle | Cool compress; no heat, alcohol or hard exercise |
| A bruise, more often around the eyes | Possible: thin skin with vessels near the surface | It fades by itself. Cover it once the skin has closed |
| One lump that stays after the rest have gone | Material may sit unevenly or too near the surface | Have it examined, not massaged. Ultrasound shows where it sits |
| Itching or hives spreading beyond the treated area | Possible allergic reaction | A doctor the same day, or A&E if none can see you |
| Fever, spreading redness, pus, or a red hot lump | Possible infection | A doctor the same day, or A&E if none can see you |
| Skin turning white, grey or mottled, or pain that is getting worse | Possible blocked blood vessel | Urgent assessment by the injector or A&E now |
| Change in vision or eye pain | Emergency | Call 995 |
| Trouble breathing or swallowing, or swelling of the tongue or throat | Emergency | Call 995 |
Aftercare
Skip make-up, heat, alcohol and vigorous exercise. A cool compress can ease swelling while the papules start to flatten.
The time to restart depends on how your skin settles, and it is given in your written aftercare instructions.
Papules settle and bruising fades. Any change in texture or hydration is gradual.
Increasing pain needs urgent assessment by the injecting doctor or at A&E. Spreading redness or swelling that does not subside needs a doctor the same day, or A&E if none is available.
When does change show, and how long does it last?
Any change shows slowly, not on the day. The early bumps are not the result. Texture and hydration are judged later, once the bumps and any bruising have gone, because polynucleotide relies on your own repair response and that differs from person to person.
No duration can be promised. Plans are staged, with a first phase and then maintenance spaced further apart if it is wanted, and each phase is reviewed before the next is set. No standard course is quoted. Because change is gradual, a visit just before an event brings the bumps but not the change you are hoping for. Results vary.
What are the side effects of Rejuran?
Like any injectable, Rejuran has risks that you should hear about first. Small papules, swelling, tenderness and bruising are common, more so around the eyes. Nodules are less common, and they can form where material sits unevenly or too superficially. Infection is also less common. Allergic reaction is rare. Published evidence on polynucleotides is limited, and most of it is of low or moderate quality.
What have studies of polynucleotide measured?
Studies have measured skin-quality features, and the evidence is still limited. A 2025 systematic review found nine studies with 219 patients, all of low or moderate quality. [3] Its authors found side effects generally mild and transient. Injection areas and techniques varied, and the authors said rigorous, high-quality studies are still needed.
Single trials are small. A 2022 randomised, double-blind, split-face trial of 27 people compared a polynucleotide filler on one side with non-cross-linked hyaluronic acid on the other, around the eyes. [4] Visual analogue scale and global aesthetic improvement scores did not differ significantly. Instrument readings of roughness, pore volume, elasticity and hydration favoured the polynucleotide side, and no serious adverse events were reported. The abstract does not name the product, so it may not be a Rejuran preparation.
None of this predicts your own response, and results vary.
How much does Rejuran cost in Singapore?
Treatment is planned individually, so cost follows the plan and not a published list. No price is set beforehand, so a written quote is given at consultation. It depends on the area, the preparation, the amount used, the delivery method, whether other treatments are needed, and how the plan is staged. Treatment for appearance is not claimable under MediSave or MediShield Life, and most private insurance plans exclude it.