PDRN and Salmon DNA in Skincare: What Is Claimed

PDRN is DNA purified from salmon sperm, labeled Sodium DNA. What the research supports, what it does not, and why molecular size matters.

Ingredients
21 AUG 2026
11 min read

PDRN is polydeoxyribonucleotide, a mixture of DNA fragments purified from salmon or trout sperm cells. On a cosmetic ingredient list it appears under the INCI name Sodium DNA. The clinical research on injected PDRN is real but small. Evidence for topical PDRN on intact skin is thin and recent. Most of the marketing runs ahead of it.

What is PDRN in skincare?

PDRN is a family of DNA fragments running from 50 kDa up to about 1,500 kDa. A 2021 review in Marine Drugs gives that range and names the source. It is the sperm cells of salmon trout (Oncorhynchus mykiss) or chum salmon (Oncorhynchus keta).

The extract is deproteinized. You are not putting sperm on your face. You are putting purified, fragmented fish DNA on your face, stripped of its proteins and peptides.

The proposed mechanism has two parts. PDRN acts as an agonist at the adenosine A2A receptor, and it feeds the nucleotide salvage pathway. A 2026 narrative review in Cureus describes A2A activation as suppressing inflammatory cytokines and raising VEGF. The salvage pathway supplies nucleotides to dividing keratinocytes and fibroblasts.

Note what the receptor is called. The target is the adenosine receptor. Adenosine itself weighs 267.24 g/mol, according to PubChem. PDRN is roughly 190 to 5,600 times heavier. Hold that gap.

Why "Sodium DNA" appears on your ingredient list

Sodium DNA is the INCI name for the sodium salt of deoxyribonucleic acid. COSMILE Europe lists one declared function for it: skin conditioning. It also lists the origin as animal, synthetic or plant.

That last detail matters more than any brand will tell you. The INCI name does not name the species. It does not name the fragment size. Two products can both say Sodium DNA and contain different molecules.

Position on the list is a weak signal too. Under 21 CFR 701.3(f), a brand may group ingredients at 1 percent or less. Those may then sit in any order. So a low position does not fix the concentration. The order inside that tail carries no information.

Ask a brand claiming PDRN for two numbers: the concentration in ppm, and the molecular weight range. The Cureus review notes that molecular weight is inconsistently reported even in published studies.

PDRN, PN, Sodium DNA and adenosine compared

Term	What it is	Size	Where you meet it
PDRN	Shorter DNA fragments from salmonid sperm	50 to under 1,500 kDa	Injectables, ampoules, creams
PN (polynucleotide)	Longer chains of the same material	At or above 1,500 kDa	Injectable clinic treatments, and topical use after a procedure
Sodium DNA	The INCI label name for DNA sodium salt	Not specified by the name	Cosmetic ingredient lists
Adenosine	A single small nucleoside	267.24 g/mol	Serums and ampoules

The PDRN and PN split is drawn at 1,500 kDa in the Cureus review. It puts PDRN below that figure and PN at or above it. Marine Drugs instead writes the PDRN range as 50 to 1,500 kDa. The two sources differ at the endpoint, and nothing here turns on it. The Cureus review also assigns the two materials different jobs. PDRN works through the receptor and the salvage pathway. PN forms a viscous three-dimensional matrix in the dermis and acts through matrix remodeling.

So a PN injectable and a PDRN ampoule are not the same product at two strengths. They are different molecules doing different things by different routes.

What the research on PDRN actually shows

Start with volume. A 2026 systematic review in Cureus searched PubMed, Embase and CENTRAL through January 2026. It found seven randomized trials covering 183 participants in total, across facial aesthetics, scar prevention and wound healing.

Seven randomized trials. One hundred and eighty-three people. Only three of the seven tested PDRN rather than PN. That is the randomized base for an ingredient sold worldwide.

The authors did not pool the results. Formulations, routes, schedules and outcome measures varied too much for meta-analysis. Several trials raised concerns under the Cochrane risk-of-bias tool. One was rated high risk for absent blinding and manufacturer sponsorship.

One finding is consistent. The clearest results sit in wound healing, where PDRN shortened healing time and sped re-epithelialization. No serious treatment-related adverse events were reported in any of the seven trials.

That profile fits the drug history. The narrative review records that the Italian Medicines Agency approved PDRN in 1994. Its listed uses were skin ulcers, dystrophic connective tissue disorders and superficial wounds. The Marine Drugs review notes that Korea approved PDRN as a DNA-derived drug.

Now the gap. Search ClinicalTrials.gov for polydeoxyribonucleotide and you get 16 registered studies as of August 2026. Read the intervention column. Most deliver it by injection or another clinical procedure, not by topical application. Three apply a topical formula with microneedling. Two of those enrolled 30 participants each, and one enrolled 25.

Can PDRN get through intact skin?

This is the question the category avoids. Here is the arithmetic.

The 500 Dalton rule appeared in Experimental Dermatology in 2000. It argues a compound must be under 500 Da to cross the corneal layer. PDRN runs from 50,000 to 1,500,000 Da. That is 100 to 3,000 times the proposed ceiling.

The rule is a rule of thumb, not a law, and later work has found exceptions. It still frames the problem correctly. A molecule of that size does not stroll through the stratum corneum because a label says it should. This is the same reason your serum sits on top and dries.

The best topical evidence to date is a 2026 paper in PLOS One. It tested a salmon-derived PDRN of roughly 1,200 base pairs, averaging no more than 850 kDa. Confocal Raman spectroscopy tracked signal into the viable epidermis of a reconstructed epidermal model over 24 hours. A labeled-tracer study in porcine skin supported it.

Read the fine print. Three of the five authors work at commercial skincare biotech firms. The porcine work followed a FITC label, and a label can travel without its intact carrier. The in-vivo Raman portion used one volunteer, and relative penetration reached about 3 percent at 24 hours. The clinical arm enrolled 31 Chinese women aged 35 to 55. Its design was randomized, double-blind and split-face over 28 days.

High-frequency ultrasound compared a 0.1 percent PDRN eye cream against 0.1 percent retinol. Gains in periocular dermal thickness and density were roughly two-fold greater. That is a real finding at 31 people and four weeks. It is not proof that every ampoule listing Sodium DNA does anything at all.

What happens when you apply PDRN after microneedling

Needling changes the size question, which is why the two subjects keep meeting. A 2021 review in Acta Pharmaceutica Sinica B describes microneedles as generating reversible microchannels that let macromolecules permeate.

Those channels are temporary. A 2011 study in Pharmaceutical Research measured barrier recovery in hairless rat skin within three to four hours. Unoccluded channels closed within 15 hours. That is animal data, and human timing will differ.

One randomized trial in the systematic review paired microneedling with topical salmon PDRN at 3 percent. Vera and colleagues published it in 2025, in 24 women aged 30 to 50. The comparator arm received microneedling with platelet-rich plasma, over six weeks. The review reports greater wrinkle reduction with PDRN and comparable pigmentation outcomes. There was no untreated control, and the review rated the trial as raising some concerns for bias.

The best-controlled split-face trial is a 2022 study in Dermatology and Therapy. Thirty subjects with Fitzpatrick types III to V had three radiofrequency microneedling sessions at two-week intervals. Each face received topical polynucleotides on one side and saline on the other.

Twenty-nine completed. Imaging showed faster improvement on the treated side at two months. Mean pain scored 2.2 out of 10, and no serious adverse events occurred. One center, one device, 29 people, one topical agent.

The two 2026 reviews are scoped differently, so read them together. The systematic review counted seven trials across three indications. The narrative review asks a narrower question. It states that no published human randomized trial has compared PDRN as a post-procedure modifier in aesthetic patients. That covers laser, peel, needling and radiofrequency. The Vera trial above is the closest counterexample to that statement. The 2022 split-face trial used polynucleotides, not PDRN.

Safety before technique

Needling is a controlled injury and the aftercare is not optional. Skip a session on active acne, an active infection, a cold sore outbreak, broken skin or sunburn. Do not needle on oral isotretinoin. Speak to a clinician first with a keloid history, during pregnancy, or on blood thinners.

Start at the shallowest depth and stay there for several sessions. Read who should not microneedle and the aftercare rules before you touch a dial. Apply nothing fragranced, acidic or exfoliating to open channels, and keep frequency low.

Five PDRN claims that outrun the evidence

"Clinically proven to regrow collagen." The systematic review found three randomized PDRN trials among seven. That does not settle an outcome claim.
"Same as Rejuran in a bottle." Rejuran is a purified PN injectable at 20 mg/mL. A cream is neither that molecule nor that route.
"Penetrates deep into the dermis." The Raman work in the one delivery paper stopped at viable epidermis. The arm that reached dermis was porcine skin following a tracer.
"Contains PDRN" with no number. Sodium DNA on a list carries no concentration and no molecular weight.
"Salmon sperm facial." The material is deproteinized, fragmented DNA. The phrase is a headline, not a description.

Is PDRN vegan, and does plant PDRN work?

Salmonid PDRN is animal-derived, so vegan alternatives are an active research area. A 2025 paper in Biochemical and Biophysical Research Communications tested plant PDRN from Gynostemma pentaphyllum callus. Its antioxidant and wound-healing effects in cell assays were comparable to salmon PDRN. It also raised barrier gene expression. The abstract reports those barrier-gene results without a salmon PDRN comparison.

Related work has examined low-molecular-weight PDRN from Paeonia lactiflora. That paper adds one four-week human study of ten subjects. It measured barrier recovery and periorbital elasticity. Both plant papers were written by authors employed at the ingredient companies developing the material. "Vegan PDRN" is a sourcing statement today, not an equivalence claim.

Where re:tones sits on PDRN

Our 01 re:vive-B3 Pore Tightening ampoule lists Sodium DNA. The composition sheet puts it at 100 ppb, published on the 01 science page. Our Sodium DNA is cleaved to 10 to 50 base pairs. At roughly 650 Da per base pair, that is about 6.5 to 32.5 kDa. That is below the 50 kDa floor this article uses for PDRN, so it is not PDRN. It is also 13 to 65 times the 500 Da ceiling this article just used. We make no claim that it crosses intact skin. The ampoule is named for Niacinamide at 21 percent. That is the figure we stand behind.

The same discipline applies to the rest of the line. Our argument is about published specs and stated concentrations, not about any single trending molecule. The re:tones Tap Pen has an 8 micron tip array. The depth collar runs from 0.5 to 1.5 mm with no clicks. Six intensity settings sit separate from depth. The cartridge feeds the ampoule to the tip, so it dispenses as you work. That is a description of the hardware. We make no claim about what reaches your skin or what your skin does with it. The re:tones Tap Pen and the re:tones ampoules do not diagnose, treat, cure or prevent any disease.

If PDRN research matures into strong human topical evidence, that will be worth saying. It has not yet. Saying so is more useful to you than another paragraph of adjectives.

Frequently asked questions about PDRN and salmon DNA

Is PDRN the same thing as salmon sperm skincare?

Yes, in origin. PDRN is purified from the sperm cells of salmon trout or chum salmon, per the Marine Drugs review. The extract is deproteinized, so what reaches the formula is fragmented DNA rather than intact cells. On the label it appears as Sodium DNA, which does not name the species.

Does topical PDRN actually absorb into skin?

The honest answer is that nobody has settled it. PDRN runs from 50 kDa to about 1,500 kDa. That is far above the 500 Da threshold proposed for barrier crossing. One 2026 PLOS One study tracked a preparation averaging no more than 850 kDa. The signal reached viable epidermis in a reconstructed model. That is one paper, with a single-subject in-vivo component and industry-affiliated authors.

What is the difference between PDRN and PN?

Chain length and mechanism. The Cureus narrative review places PDRN below 1,500 kDa and PN at or above it. PDRN is described as acting through the adenosine A2A receptor and the nucleotide salvage pathway. PN forms a viscous matrix in the dermis and acts through extracellular matrix remodeling.

Is PDRN safe if I have a fish allergy?

No published trial answers this directly, so treat it as unknown. Parvalbumins are the main source of fish food allergy, and PDRN is deproteinized. That is a reasonable expectation, not a tested guarantee. Ask an allergist before using a salmon-derived product on compromised skin.

Should I use PDRN after microneedling at home?

No published randomized trial has tested topical PDRN after at-home needling. One randomized trial in the cited review paired microneedling with topical salmon PDRN at 3 percent. It enrolled 24 people. It was a clinic procedure, not an at-home device, and it had no untreated control. Follow the safety rules, start shallow, and apply nothing acidic or fragranced to open channels.

How much PDRN should a serum contain?

No consensus figure exists, and most brands do not disclose one. The Cureus review notes that molecular weight is inconsistently reported even in published studies. Under US labeling rules, ingredients at 1 percent or less may be grouped at the end. That group carries no order. Ask for the number in ppm.

Is PDRN better than retinol or peptides?

The comparison is not settled. One 28-day split-face study of 31 women compared a 0.1 percent PDRN eye cream with retinol. Periocular dermal thickness gains were roughly two-fold greater. Retinol has decades of larger trials behind it. One small study does not overturn that.

Why do Korean brands feature PDRN so heavily?

Regulatory history and proximity. Korea approved PDRN as a drug, and Korean clinics popularized PN injectables. The cosmetic versions followed the clinical ones. Read more on how K-beauty ingredient trends form and how quickly they cross into export markets.