A Serum Is Not a Skin Booster

Short answer. A PDRN injection in Korea is a prescription product made from purified fish DNA fragments and injected into the skin by a doctor, while a PDRN serum is a cosmetic that sits on the surface, so the same four letters describe two different things. Rejuran, the name most visitors know, is technically PN (polynucleotide), a longer-chain cousin regulated in Korea as a medical device rather than a drug; ask which product is in the syringe, not which trend is on the menu.

The ingredient went viral. The injection did not change.

PDRN is now in serums from Korean brands and from global names that launched their own versions this year. In Seoul, the same word shows up on clinic price tiles, next to "salmon DNA," "Rejuran," and "skin booster." Visitors who bought a bottle at home message a Gangnam clinic asking for "the real PDRN." The coordinator books whatever the clinic stocks. Sometimes that is PDRN. Often it is PN.

If you remember one test, remember this. Ask for the product name and whether it is a drug or a medical device. If the answer is a brand you can look up, you know what you are getting. If the answer is "our PDRN," you are buying a word.

What does PDRN actually mean?

PDRN stands for polydeoxyribonucleotide. It is DNA, purified mainly from salmon or trout sperm cells, broken into fairly short fragments. (ref. 2, 3) In the lab and in wound-healing studies, PDRN appears to act mostly by switching on the adenosine A2A receptor, a signal linked to calmer inflammation, new small blood vessels and tissue repair. Its broken-down pieces can also be recycled by cells as building blocks. (ref. 2, 3)

PN, short for polynucleotide, is the same family with longer chains. Longer chains hold water and form a thicker gel, so PN behaves more like a scaffold in the skin than a signal. (ref. 2) That is why PN products are sold as skin boosters and even as joint injections. (ref. 2, 4)

There is no agreed molecular-weight line between the two, and a 2025 review notes that labels use the terms loosely. Some products labelled PN turned out on analysis to be mostly PDRN. (ref. 2, 5) The words on the box are a starting point, not a lab report.

How is a PDRN serum different from a PDRN injection?

By where it goes and what it is allowed to be. A serum is a cosmetic. In Korean cosmetics, PDRN is usually listed on the label as sodium DNA or hydrolyzed DNA, and plant-based versions now exist too: one luxury launch uses PDRN from rice DNA. (ref. 1, 2) It is applied to the top layer of skin. Most of the published research on PDRN is on injections, cells and animals, so how much a cream does depends on the whole formula, not the headline ingredient. (ref. 2)

An injection is a medical product placed into the dermis with a needle. In Korea, the regulator, the Ministry of Food and Drug Safety (MFDS), approves PDRN injections as prescription drugs, mainly for wound healing and tissue repair after skin grafts. PN injections such as Rejuran are regulated as medical devices. (ref. 2, 4) Clinics use both for skin-quality treatments.

Categories as described in a 2025 review citing MFDS databases and in Korean pharma press (ref. 2, 4). Not a product recommendation.

The table is the reason a serum is not a cheaper version of the injection. It is a different product in a different category, doing a different job at a different depth.

Is Rejuran PDRN or PN?

PN. Rejuran is a polynucleotide product, regulated in Korea as a medical device, and a 2025 review lists it as the example of a PN skin booster. (ref. 2) The confusion is understandable: the same company sells PDRN cosmetics, the same salmon source appears in both, and English menus use "salmon DNA" for everything. (ref. 1, 4) Our guide to Korean skin treatments covers Rejuran as one of the clinic treatments visitors ask about.

For your booking, the difference is practical. Ask which product the clinic uses, whether it is PN or PDRN, and how many cc go into one session.

What the evidence says, and what it does not

There is real research here, and it is thinner than the marketing. PDRN has decades of wound-healing work behind it, including a clinical trial in diabetic foot ulcers. (ref. 3) For cosmetic PN injections, a 2025 systematic review found nine studies with 219 patients, of low to moderate quality. The results looked promising for fine lines, texture and elasticity, side effects were mostly mild and short-lived, and the authors called for rigorous, high-quality trials. (ref. 6)

In practice, Korean dermatologists use PN widely. In a survey of 235 board-certified dermatologists, 88% used PN injections, most often for fine lines on the cheeks and around the eyes. The most common plan was three sessions spaced four weeks apart, injected with a very fine 33G needle into the dermis, and 79% combined it with lasers, radiofrequency or HIFU. (ref. 7)

What that does not tell you is what one session will do to your face. Nobody can promise that. A skin-quality injection is a slow, modest change judged over weeks, not a filler and not a lift. If your goal is sagging, read our thread lift guide first. If your goal is shape, this is the wrong tool. Under-eye hollows and bags are their own question, covered in our under-eye guide.

The message that books the right injection

Send this before you pay a deposit:

1. "What is the product name, and is it PN or PDRN?"
2. "Is it a medical device or a drug in Korea?"
3. "How many cc per session, and how many sessions do you suggest?"
4. "Who injects, and is numbing cream included?"
5. "How long will the bumps or marks show? I fly on [date]."

A clinic that answers with a brand and a number is selling a treatment. A clinic that answers with "our signature PDRN" is selling a word.

Quick FAQ

What is a PDRN injection? A PDRN injection places purified, short fragments of fish DNA into the skin with a fine needle. In Korea, PDRN injections are approved by the MFDS as prescription drugs, mainly for wound healing and tissue repair, and clinics also use them for skin-quality treatments. (ref. 2, 4) It is done by a doctor, not a beautician.

What does PDRN stand for? PDRN stands for polydeoxyribonucleotide, a DNA-derived ingredient usually purified from salmon or trout sperm cells. (ref. 2, 3) Plant-based PDRN, for example from rice DNA, is now used in some cosmetics. (ref. 1)

What is the difference between PDRN and PN? Both are DNA fragments. PN (polynucleotide) has longer chains, holds more water and forms a thicker gel; PDRN has shorter chains and acts more as a signal for repair. (ref. 2) In Korea, PN injections are medical devices and PDRN injections are drugs. (ref. 2, 4)

Is Rejuran PDRN? No. Rejuran is PN (polynucleotide), regulated in Korea as a medical device. (ref. 2) The company also sells PDRN cosmetics, which is one reason the names get mixed up. (ref. 1, 4) Ask the clinic which product and which category it is.

Is a salmon DNA facial the same as a PDRN injection? Not always. "Salmon DNA facial" is a menu name that can mean a PN injection, a PDRN injection, or a topical treatment applied after a device. Ask what is injected, what is applied on the surface, and the product name.

Does a PDRN serum work like the injection? No. A serum is a cosmetic applied to the skin surface, while the injection places a medical product into the dermis. (ref. 2) Most published PDRN research is on injections, cells and animals, so a serum's effect depends on its whole formula. (ref. 2)

Why is PDRN suddenly everywhere? Because it crossed from clinics into cosmetics. Spate data reported by Seoul Economic Daily on 3 October 2026 put PDRN at 37.2 million monthly interactions across Google, TikTok and Instagram, up 609.8% in a year, with global brands launching PDRN products. (ref. 1) That is a measure of interest, not of results.

Are PDRN injections approved in Korea? Yes. The MFDS has approved PDRN injectables as prescription drugs, mainly for wound healing and tissue regeneration such as after skin grafts. (ref. 2) PN injectables such as Rejuran are approved as medical devices. (ref. 2, 4) Approval describes a product category, not a promised result for you.

What does a PDRN or PN injection feel like? Many small pricks. Korean dermatologists most often use a very fine 33G needle with many shallow punctures into the dermis. (ref. 7) Numbing cream is common; ask whether it is included and how long it sits before the injections start.

How many sessions of PN or PDRN do people get? In a survey of 235 Korean dermatologists, the most common plan for PN was three sessions spaced four weeks apart. (ref. 7) That fits a longer stay or repeat trips better than a single weekend. Your clinician may suggest a different plan.

Is there downtime after a PDRN injection? Usually little. Expect needle marks and small bumps that settle over a short period; side effects in published PN studies were mostly mild and short-lived. (ref. 6) Ask how long the bumps last before you book it the day before a flight or a photo.

Can I get PDRN injections on a short trip to Seoul? Yes, one session fits a short trip. But the commonly used plan is a series several weeks apart, so one session is the start of a plan, not the whole plan. (ref. 7) Ask whether the clinic expects you back and what a single session can realistically do.

Can PDRN be combined with lasers? Often. In the Korean survey, 79% of dermatologists using PN combined it with lasers, radiofrequency or HIFU. (ref. 7) Combining raises the bill and can change the downtime, so ask what each part is for.

Is PDRN better than filler? They do different jobs. Filler adds volume or shape. PN and PDRN are used for skin quality, and a 2025 review describes PN as structural support and hydration, not volume. (ref. 2) If you want a fuller cheek or lip, a skin booster is not the tool.

Does PDRN tighten sagging skin? It is not designed to. Published studies of PN focus on fine lines, texture and elasticity, and the evidence is still limited. (ref. 6) For sagging, the conversation is about devices, threads or surgery; see our thread lift guide.

Can PDRN be used under the eyes? Korean dermatologists commonly use PN for fine lines below and around the eyes. (ref. 7) Bags and deep hollows are different problems; our under-eye guide explains which ones need surgery.

What is the difference between PDRN and exosomes? They are different ingredients. PDRN is DNA fragments. Exosomes are tiny particles released by cells. They have separate evidence bases, so ask for the product name and its regulatory category for each, rather than treating them as interchangeable.

How is a PDRN injection priced in Korea? Clinics usually quote by product, cc and number of sessions, and prices vary by clinic. This guide prints no price ranges. Ask for the product name, the cc per session, the number of sessions and whether numbing is included, in writing.

Is PDRN safe? Reviews describe PDRN and PN as well tolerated, with no serious safety signal reported in the studies they cover, and side effects in cosmetic PN studies were mostly mild and short-lived. (ref. 2, 6) Any injection can bruise or get infected, so choose a licensed doctor and a clean room.

Who should skip PDRN or PN injections? Anyone pregnant or breastfeeding, anyone with an active skin infection where the needle goes, and anyone with a known allergy to the product or its fish source should talk to a clinician first. If you are on blood thinners, expect more bruising and say so before treatment.

Medical note

This article is for general education and is not medical advice, a diagnosis, or a promise of outcome. It prints no prices; ask the clinic for an itemized quote. Products and brands are named to explain categories and how Korea regulates them, not to recommend a product or clinic, and cosmetics brands are mentioned only as industry context. If you are pregnant or breastfeeding, have a fish allergy, an autoimmune condition, or take blood thinners, speak to a qualified clinician before any injectable treatment.

References

1. PDRN Interest Jumps 610% as Dior, L'Oreal Join K-Beauty Trend. Seoul Economic Daily, October 3, 2026. Spate data: 37.2 million monthly interactions, up 609.8% year on year. Link
2. Kim ST. Comparison of Polynucleotide and Polydeoxyribonucleotide in Dermatology: Molecular Mechanisms and Clinical Perspectives. Pharmaceutics, 2025. Includes the Korean regulatory classification (PN medical device, PDRN pharmaceutical) citing MFDS databases. PMC
3. Squadrito F, Bitto A, Irrera N, et al. Pharmacological Activity and Clinical Use of PDRN. Frontiers in Pharmacology, 2017. Link
4. 연어 DNA로 의약품·의료기기 시장 잡는다... PDRN과 PN 무슨 차이 (Salmon DNA in drugs and devices: the difference between PDRN and PN). Hit News, May 27, 2025 (in Korean). Link
5. Marques C, Porcello A, Cerrano M, et al. From Polydeoxyribonucleotides (PDRNs) to Polynucleotides (PNs): Bridging the Gap Between Scientific Definitions, Molecular Insights, and Clinical Applications of Multifunctional Biomolecules. Biomolecules, 2025. PubMed
6. Lampridou S, Bassett S, Cavallini M, Christopoulos G. The Effectiveness of Polynucleotides in Esthetic Medicine: A Systematic Review. Journal of Cosmetic Dermatology, 2025. PMC
7. Rho NK, Han KH, Cho M, Kim HS. A survey on the cosmetic use of injectable polynucleotide: The pattern of practice among Korean Dermatologists. Journal of Cosmetic Dermatology, 2024. PubMed