Rejuran and PDRN "salmon DNA": injections vs serums explained
What PDRN and Rejuran are, how "salmon DNA" injections differ from PDRN serums, what the evidence shows, side effects, costs in general and who should avoid it.
Written by the Glowpedia team · not yet reviewed by our dermatologist
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"Salmon sperm facials" sound like a joke, but PDRN has become one of the biggest K-beauty trends. Injected in clinics, it has a real medical background and a small but growing body of studies. In a serum or cream, it is mostly a gentle, hydrating ingredient with limited evidence so far.
Quick answer: PDRN (polydeoxyribonucleotide) is purified DNA fragments, usually from salmon or trout sperm cells. Injected into the skin, as in Rejuran and similar "skin boosters", it is used to improve texture, fine lines and skin quality, with small, mostly short studies behind it. PDRN serums cannot reach the same depth: expect hydration and a calmer look, not injection results.
What is PDRN?
PDRN stands for polydeoxyribonucleotide, a mix of short DNA fragments. It is extracted from the sperm cells of salmon or trout and then purified to remove proteins. In medicine, especially in Italy and South Korea, it has been studied for wound healing, diabetic foot ulcers and tissue repair.
Researchers think it works in two main ways:
- Calming and repair signals: PDRN activates adenosine A2A receptors, which are switches on cells linked to less inflammation and better repair.
- Recycled building blocks: cells can reuse the small pieces of DNA (nucleotides) through a "salvage pathway", which may help skin cells repair themselves.
Most of this comes from lab and animal research. How much these effects matter for wrinkles or skin texture in people is still being studied. Find more on the ingredient family on our PDRN page.
PDRN, PN and "salmon DNA": what the names mean
You will see several names that sound alike. They are related, but not the same.
| Name | What it is | Where you find it |
|---|---|---|
| PDRN (polydeoxyribonucleotide) | Shorter DNA fragments | Some injections, many serums and creams |
| PN (polynucleotides) | Longer DNA chains from the same fish source, forming a thicker gel | Most "salmon DNA" skin booster injections |
| Sodium DNA | A common name for DNA fragments on cosmetic ingredient lists | Serums, creams, sheet masks |
| "Salmon DNA" or "salmon sperm" | Marketing names for any of the above | Social media, clinic menus |
On a cosmetic label, PDRN often appears as sodium DNA. Injections and creams can share a name but behave very differently, because what matters most is how deep the ingredient goes.
What is Rejuran, and how does the treatment work?
Rejuran is a brand of polynucleotide (PN) injection from South Korea, and it has become the best-known name for this kind of treatment. Similar products exist in Europe and elsewhere. They are often called "skin boosters": injections that aim to improve skin quality rather than add volume like a filler.
What a session is like
A trained clinician places many tiny injections into the upper layer of the skin, across the face or in a target area such as under the eyes, the neck or areas with acne scars. Numbing cream is usually applied first, because the treatment can sting. A session often takes under an hour.
How many sessions
In Korea, a common plan is a course of three or four sessions spaced a few weeks apart, followed by occasional top-ups. Your clinic may suggest a different plan depending on your skin and goals.
What does the evidence say?
The evidence is promising but early.
- A 2025 systematic review (a study that pools earlier research) found nine studies of polynucleotide injections for cosmetic use, with 219 patients in total. Several showed improvements in wrinkles, texture and elasticity, and side effects were usually mild and short-lived.
- The same review rated the studies as low to moderate quality and said larger, well-designed trials are needed.
- Many studies were small, short, done in one country, or used different injection techniques, which makes them hard to compare.
In short: polynucleotide injections may improve skin quality modestly, especially texture and fine lines, but they are not a substitute for proven basics such as daily sunscreen and retinoids.
PDRN serums and creams: what can they do?
DNA fragments are large molecules, so when you apply them to the skin, most stay near the surface. There, PDRN acts as a gentle, water-binding and soothing ingredient. It suits dehydrated skin and is usually well tolerated.
Independent studies on topical PDRN for wrinkles are limited. Most evidence is from lab studies or small studies funded by brands. Some clinics apply PDRN after microneedling to help it get in, but that is a procedure, not a home routine. If you enjoy a PDRN serum, think of it as a pleasant hydrating step.
Injection or serum? A quick comparison
| Injected PN or PDRN | Topical PDRN | |
|---|---|---|
| How deep it goes | Into the dermis (the deeper layer of skin) | Mostly the surface |
| Evidence | Small clinical studies, low to moderate quality | Limited, mostly lab or brand-run |
| Possible effects | Texture, fine lines, skin quality | Hydration, calmer-looking skin |
| Who does it | A trained, licensed clinician | You, at home |
| Downtime | Bumps, redness, possible bruising for a few days | None for most people |
| Cost | High per session, repeated over a course | Moderate |
Risks, side effects and who should avoid it
After injections, most people have small bumps, redness and tenderness for a day or two. Bruising is possible, especially under the eyes. Rarer risks of any injection include infection, lumps and allergic reactions.
Be cautious, and ask your doctor first, if you:
- have a fish or salmon allergy: the material is highly purified, but caution is sensible;
- are pregnant or breastfeeding: there is little safety data, so most clinics do not offer these injections;
- have an active skin infection, cold sores or a rash in the area to be treated;
- have an autoimmune disease or take blood-thinning medicines, which can affect healing and bruising.
Before and after injections, many clinics ask you to pause strong actives such as retinoids and exfoliating acids for a few days. Follow your clinic's instructions.
Cost and regulation
Prices vary widely by country, city and clinic, and you pay per session over a course of several sessions. Prices in South Korea are often much lower than in North America, Europe or the Gulf countries, which is why some people travel for treatment.
Regulation also varies. Polynucleotide injections are approved as medical devices in South Korea and are available in Europe. In the United States, we could not find an FDA-approved PDRN or polynucleotide injection for cosmetic use as of 2025. Be wary of clinics offering imported or unlabeled products, and ask what product is used and how it is approved where you live.
How long until results
- Injections: any improvement builds gradually over the course of treatment, usually becoming visible after a few sessions. It is not instant like a filler, and maintenance sessions are needed to keep results.
- Topical PDRN: skin may feel more hydrated within days. Any change in texture is likely to be small.
When to see a doctor
- Before treatment: have a proper consultation with a dermatologist or a qualified, licensed clinician who explains the product, the risks and the plan.
- After treatment, seek medical care quickly for pain that gets worse instead of better, spreading redness or warmth, pus, fever, lumps that do not settle within a couple of weeks, or any change in vision.
- If you have a skin condition such as rosacea, eczema or active acne, ask a dermatologist whether injections are suitable for you.
FAQ
Is it really made from salmon sperm?
Yes. The DNA is usually extracted from the sperm cells of salmon or trout and then highly purified to remove proteins.
Is PDRN vegan?
No. It is animal-derived. Some brands now sell plant-based "PDRN-like" ingredients, but these are different materials and have even less research behind them.
Is Rejuran the same as a filler?
No. Fillers add volume to hollows and folds. Polynucleotide skin boosters aim to improve the quality and texture of the skin, with a subtler effect.
Can I use PDRN with retinol or vitamin C?
Topical PDRN is gentle and is generally fine to use alongside other products. Around injections, follow your clinic's advice about pausing strong actives.
Does it help under-eye dark circles?
Some clinics use skin boosters under the eyes, where skin is thin. Results vary, and dark circles have several causes, so a consultation first is sensible.
Sources
- Pharmacological activity and clinical use of PDRN (PubMed Central, NIH)
- The effectiveness of polynucleotides in esthetic medicine: a systematic review (PubMed, NIH)
- Injectable "skin boosters" in aging skin rejuvenation: a current overview (PubMed Central, NIH)
- From polydeoxyribonucleotides (PDRNs) to polynucleotides (PNs): bridging the gap between scientific definitions, molecular insights, and clinical applications (PubMed, NIH)