What Is PDRN, and Why Is It in Serums?

PDRN stands for polydeoxyribonucleotide: a mixture of DNA fragments, most often purified from the sperm cells of salmon species such as chum salmon or salmon trout. That is where the nickname "salmon DNA skincare" comes from. On an ingredient list, it usually appears under its cosmetic name, sodium DNA, rather than as "PDRN."

The ingredient did not start on a beauty counter. Researchers have studied PDRN and its relatives since the 1990s for wound care and for skin quality in aesthetic medicine, and in Korea it became widely known through injectable skin boosters offered in aesthetic clinics. Once the name was familiar, cosmetic brands followed with a far more accessible format: serums, ampoules, essences and creams you apply yourself.

A serum is the natural home for it. A thin, water-based texture spreads evenly, stays on the skin rather than being rinsed off, and layers easily under a moisturizer. In practice, most PDRN serums are built as hydration products: the DNA-derived ingredient sits alongside humectants such as hyaluronic acid or glycerin, and the everyday result people describe is skin that looks plumper, smoother and more comfortable.

In short, if you are searching "what is PDRN in skincare," the most useful answer is this: a salmon-derived DNA ingredient, borrowed from clinical aesthetics, reformulated as a leave-on product for hydrated-looking skin.

PDRN vs PN: What Is PN, and How Is It Different?

PN stands for polynucleotide. It comes from the same source material as PDRN, purified salmon DNA, and the two are often mentioned in the same breath. The difference is length. PN refers to longer DNA chains; PDRN refers to shorter and medium-length ones.

For years the two terms were used almost interchangeably, which a 2025 review in the journal Biomolecules described as a real source of confusion. The authors proposed a simple size cutoff: fragments below 1,500 kDa would be called PDRN, and fragments at or above it would be called PN. Not everyone uses that line yet, but it is the clearest working definition available.

Length changes how the material behaves. A 2025 review in Pharmaceutics comparing the two describes PN, with its longer fragments, mainly in terms of the structural, gel-like support it lends within tissue, and PDRN, with its shorter sequences, mainly in terms of how it interacts with skin cells through signalling pathways. These are findings from laboratory and clinical research on the ingredients themselves, largely in injectable form, not promises about any particular jar.

• PDRN (polydeoxyribonucleotide): shorter and medium-length DNA fragments; the name most shoppers know; the most common form in PDRN serums and essences.
• PN (polynucleotide): longer DNA chains from the same salmon source; long associated with clinic skin boosters; now appearing in home-care formulas as well.
• On the label: both are often listed as sodium DNA, so the distinction is usually explained by the brand rather than by the ingredient list.

That is why "PN skincare" and "polynucleotide serum" have started to show up in searches next to "PDRN serum." In home care, the newest formulas tend to combine the two rather than choose between them, and brands increasingly name both on the front of the pack. If you care about the distinction, read the brand's own description of what it includes, because the INCI list alone will not tell you.

PDRN Serum vs Clinic PDRN: Two Tools, Two Jobs

The word "PDRN" now covers two very different experiences. In a clinic, a practitioner places DNA-derived material beneath the skin's surface. At home, a serum is spread across the surface and stays there. It is more useful to think of these as different tools for different jobs than as a stronger and weaker version of the same thing.

The reason is size. DNA fragments are large molecules, and healthy skin is designed to keep large molecules out. Most of what is written about PDRN's effects comes from injection studies, while research on leave-on products is newer and smaller. There are early signals: a 2026 study in PLOS One looked at one specific medium-length PDRN preparation and reported signs of it reaching the upper, living layers of the epidermis in laboratory and pilot tests. That is one preparation in one study, from a research team with industry co-authors, so it is a reason for interest rather than a verdict on every PDRN serum.

What a serum can reasonably do is what good skincare does: keep the surface hydrated, support a comfortable-feeling skin barrier, and leave texture looking smoother and more even day to day. Clinic treatments are chosen for different goals, after a consultation, and they come with their own planning. If you are weighing that route, our guides to PDRN skin boosters in Korean clinics and to Rejuran explain how those treatments work, and our piece on Seoul's shift toward collagen boosters and PDRN covers the wider clinic trend.

Many people use both: clinic sessions a few times a year, and a PDRN or PN serum as part of the routine in between. Neither replaces the other.

Korea's PDRN and PN Home-Care Shelf

Walk through a Seoul beauty store and PDRN is everywhere: essences, ampoules, creams, toner pads and sheet masks. Brands you will see include Rejuran, which offers a home-care line alongside its clinic name, as well as Dr.Reju-All, VT Cosmetics, medicube and Anua, among many others. Most pair PDRN with familiar hydrators such as hyaluronic acid, and some add peptides or niacinamide. The right choice depends on your skin type, the texture you like and what else is already in your routine.

A newer direction is formulas that put PDRN and PN together. One example is Dr. Elreju PDRN + PN 2-Part Booster Serum, the consumer line from the company behind Elreju, a skin booster supplied to Korean aesthetic clinics. Its first defining fact is right on the label: PDRN and PN in the same formula. It comes as two vials. Vial 1 is a freeze-dried powder containing PDRN and PN, and Vial 2 is a hyaluronic acid liquid. You pour the liquid into the powder vial once, shake until it dissolves, keep it refrigerated, and apply it by hand each evening, with one set lasting seven days. It is a cosmetic, and the brand describes it simply as a "booster serum for daily glow." Full disclosure: BeautiPin stocks Dr. Elreju in our shop.

How to Use a PDRN Serum in Your Routine

A PDRN serum slots into a routine the same way most serums do: after cleansing and toner, before heavier creams. The usual Korean rule of thin to thick applies. Press a few drops over the face and neck, give it a moment to settle, then seal it in with a moisturizer.

Evening is the easiest time to start, since it lets the serum sit on the skin undisturbed. If you use it in the morning, finish with sunscreen as always. Two-part formats, where you mix components before first use, should follow the brand's own mixing, storage and timing instructions exactly.

PDRN and PN get along with most common ingredients. Hyaluronic acid, ceramides, panthenol and centella are natural partners. If you already use stronger actives such as retinoids or exfoliating acids, introduce the new serum on its own first and add one change at a time, so you can tell what your skin is responding to.

Before your first full application, try a small amount on the inner forearm and wait about a day. Then give the serum a fair trial: four to eight weeks of consistent use is a reasonable window to judge how your skin looks and feels, since daily hydration builds gradually rather than overnight.

What a PDRN Serum Can't Do

Honest limits make it easier to choose well. A PDRN or PN serum does not replace clinic treatments that place material beneath the skin, and it should not be expected to deliver the same kind of results. It is skincare, and it works on the terms skincare works on.

The evidence is still young. Much of what is known about PDRN comes from injection research, and studies of leave-on formulas are small, recent and often run on one specific preparation. Results from one product do not transfer automatically to another, and how skin looks after weeks of use varies from person to person.

Some concerns need a diagnosis before a product. Deep wrinkles, scarring, persistent redness and pigmentation have different causes, and a serum is not the tool that addresses them. It also does nothing for sun protection: daily sunscreen remains the most important step for keeping skin looking even and healthy, with or without PDRN.

Finally, a few practical notes. Most PDRN is salmon-derived, so it is not vegan, and anyone with a fish allergy should check with a doctor first. Do not apply it to broken skin or to areas with eczema or dermatitis, and stop if redness, swelling or itching appears. Whatever a serum does for how your skin looks lasts only as long as you keep using it.