What is PDRN skincare? The salmon DNA ingredient explained

By the Real Korea 101 editorial team · Published November 13, 2026 · Sources checked November 13, 2026

Short answer: PDRN (polydeoxyribonucleotide) is a purified mix of DNA fragments, most often extracted from salmon. It is used in two very different ways: as an injectable treatment given in clinics, and as an ingredient in creams, serums and masks you apply at home. Under Korean law, a PDRN cosmetic is still a cosmetic, which means it is legally defined as having only light effects on the body and may not be advertised as if it were a medicine.

What PDRN actually is

PDRN stands for polydeoxyribonucleotide. In plain terms, it is DNA that has been extracted, purified and broken into fragments. A 2024 review in the International Journal of Biological Macromolecules describes PDRN as a registered DNA-derived proprietary drug containing a mixture of DNA fragments with molecular weights between 50 and 1500 kDa, extracted mainly from salmon, with a highly pure active substance (more than 95 percent). The same review notes that researchers are now looking at other sources besides salmon and comparing their advantages and disadvantages.

A 2025 narrative review in Biomolecules says PDRN and the closely related PN (polynucleotides) have drawn scientific attention since the 1990s for possible uses in wound healing and skin rejuvenation, and that they are sold in several forms: gels, creams, serums, masks and injectables.

Korean company PharmaResearch, which makes the well-known Rejuran brand, says in its own press materials that it manufactures and sells medicines, medical devices, cosmetics and dietary supplements, focused on salmon-derived materials it calls DOT PDRN and DOT PN. One company spanning drugs, devices and cosmetics is part of why the ingredient name shows up in such different places.

PDRN vs PN: why the names are confusing

You will see both "PDRN" and "PN" on Korean product pages and clinic menus. They are related DNA-derived polymers, and even scientists have used the terms loosely. The 2025 Biomolecules review states that the interchangeable use of "PDRN" and "PN" in the literature has caused considerable confusion, and proposes a size-based cutoff at 1500 kDa: "PDRN" for chains below 1500 kDa and "PN" for longer chains at or above it. That is a proposal by the review authors, not a legal or industry-wide standard.

For a shopper, the practical takeaway is simple: PDRN and PN are not two unrelated ingredients, and a product's choice of label does not by itself tell you how it was made or how much is inside.

Clinic treatment vs cosmetic product

This is the distinction that matters most. A "skin booster" injection at a dermatology clinic and a PDRN serum from a beauty store may share an ingredient name, but they are regulated, used and studied differently.

What the research says so far

Injections

A 2025 systematic review in the Journal of Cosmetic Dermatology searched studies published between 2010 and 2024 on polynucleotide injections in aesthetic medicine. It found only nine studies, of low and moderate quality, covering 219 patients in total. Seven of the nine took place in Korea. The review reports that injections showed promising outcomes for wrinkles, skin texture and elasticity, with statistically significant results in several studies, and that side effects were generally mild and temporary, such as swelling, redness and itching at the injection site.

The same review is clear about its limits: none of the included studies achieved full scores in the quality appraisal, study designs varied widely, and the authors call for rigorous, high-quality studies to confirm effectiveness and safety. Two of its authors also disclosed ties to companies in the polynucleotide business. We mention this not to dismiss the work, but because it is part of the published record.

Products applied to the skin

For topical use, the evidence we could check is limited. One example is a 2010 abstract in the International Journal of Cosmetic Science describing a 12-week test in which a cream with 3 percent sodium DNA from salmon milt, or a control cream, was applied by male volunteers, ten per group. The authors reported better skin elasticity than the control after the fourth week, a tendency toward lower water loss and higher skin moisture at 12 weeks, and that more than 90 percent of the DNA cream group felt their skin roughness had improved. That is a small study, and a questionnaire result is a self-report, not a measurement.

Many other papers on PDRN are laboratory or animal studies. These are useful for scientists, but they do not tell you what a cosmetic will do on your face.

What the manufacturer says

PharmaResearch's own March 2026 press release describes its REJURAN COSMETICS line as built on its patented c-PDRN ingredient from salmon DNA, with formulas "clinically designed to improve the look of texture, hydration, and radiance". Note the wording: "the look of" is cosmetic language about appearance, which is different from a medical claim. This is manufacturer-published information, not an independent review.

How Korean law treats PDRN cosmetics

Korea's Cosmetics Act, overseen by the Ministry of Food and Drug Safety (MFDS), sets the rules that every PDRN cosmetic sold in Korea must follow. Three parts are worth knowing.

• What a cosmetic is. Article 2 defines a cosmetic as something applied to the body for cleansing, beautifying, brightening the appearance, or maintaining or improving the health of skin and hair, "which have light effects on the human body". Goods that are medicines under the Pharmaceutical Affairs Act are excluded.
• No medicine-style advertising. Article 13 forbids labeling or advertising likely to mislead consumers into thinking a cosmetic is a medicine, and forbids presenting a non-functional cosmetic as a functional one.
• Functional cosmetics need MFDS review. Products that claim to aid whitening, wrinkle improvement, UV protection and a few other listed functions must go through an MFDS evaluation or report for safety and effectiveness. Their labels must show the words "functional cosmetic" or the MFDS logo.

PDRN is not one of the functional categories in itself. So when a PDRN cream says it improves wrinkles, the question to ask is whether that specific product was registered as a wrinkle-improvement functional cosmetic, not whether it contains PDRN.

How to read a PDRN product page

1. Find where PDRN sits in the full ingredient list. Ingredient lists show what is inside; Korean law requires them on the outer package.
2. Look for the functional cosmetic mark if the product claims wrinkle, whitening or UV benefits.
3. Separate appearance words from medical words. "Helps skin look smoother" is cosmetic language. "Regenerates", "heals" or "treats" points toward a medicine, which a cosmetic may not imply in Korea.
4. Check what any "clinical test" actually measured, how many people took part and whether it compared against a control product.
5. Patch test first. The American Academy of Dermatology suggests trying a new product on a small spot, such as the inner arm, twice a day for 7 to 10 days. If you have allergies to fish, ask the brand about the source of its PDRN before using it. We could not find official guidance on this point.

New to Korean skincare in general? Our beginner routine guide explains where a serum fits.

This article explains public information and is not medical advice. For skin conditions or clinic treatments, talk to a licensed doctor.