PDRN in Skincare: What Salmon DNA Serums Can (and Can't) Do

If your feed has been full of "salmon DNA", "Rejuran" and "PDRN" lately, you're not imagining it. It's one of the most heavily marketed K-beauty ingredients of the year. The short version: the injectable form has genuine clinical evidence behind it. The serum on the shelf mostly doesn't, and the reasons are more about physics than about marketing.

What PDRN is

PDRN stands for polydeoxyribonucleotide: long chains of DNA fragments, usually extracted from salmon (or trout) sperm and purified to remove proteins. It's thought to work in two ways. It appears to activate a cell receptor called adenosine A2A, which is involved in healing and calming inflammation, and it may supply building blocks that cells reuse when repairing tissue. A close relative, polynucleotide (PN), is the other name you'll see; they're related materials processed differently (this narrative review of polynucleotides and PDRN in dermatology explains the difference).

Where the evidence is

Almost all of it is for injectable use. PDRN injections have been used clinically for wound healing and tissue repair, and in aesthetic clinics as a "skin booster". Dermatologists quoted in Dermatology Times describe the injectable evidence as strong, including split-face studies where PDRN beat a hyaluronic acid filler.

The topical evidence is thin by comparison. The same article mentions one small late-2025 trial of a plant-derived PDRN that found a modest improvement in elasticity around the eyes, which is interesting, but it was a single study of a specific formula and not representative of most serums.

The absorption problem

A rule of thumb in skin science is that a molecule needs to be under roughly 500 daltons to cross intact skin passively. Standard PDRN fragments are vastly larger: the dermatologists quoted put them at 50 to 1,500 kilodaltons, which is 50,000 to 1.5 million daltons. Applied to the surface, they are very unlikely to reach the fibroblasts deep in the dermis where the repair effect is supposed to happen. The dermatologists in that article put it bluntly: results equal to injections aren't realistic from a serum, and most brands don't publish the molecular weight, any encapsulation method or delivery data.

So what is a PDRN serum doing? Probably what its other ingredients do. Most contain hyaluronic acid, glycerin, panthenol or niacinamide, which hydrate and soothe, and those can make skin look smoother and calmer. That's useful, but it isn't DNA repair. A cheaper serum with the same supporting ingredients may do the same job.

Should you try a PDRN serum?

If you like the texture and the price doesn't bother you, it's a reasonable hydrating serum. Just don't pay a premium expecting the results people post after clinic treatments. Check what else is in the formula (our ingredient scanner will flag any pore-clogging ingredients), and look for brands that say how their PDRN is processed and cite a study on their own product rather than on injections.

Check with a doctor first if: you have a fish or salmon allergy (it's fish-derived, and we couldn't find reliable data on topical reactions either way), you're pregnant or breastfeeding (there's no safety data we could find), or you have a skin condition that is currently active. Plant-derived PDRN exists and some brands label it that way.

Using it with other products

PDRN has no known irritation or chemical conflicts, so it layers easily. Try our checker for specific pairs: niacinamide, vitamin C, retinol. The usual order applies: thinnest first, then the cream, then sunscreen in the morning. There's a short profile on the PDRN ingredient page.

If you're considering the clinic version

Treatments like Rejuran use polynucleotide injections. That's a medical procedure, not a skincare step, so ask the practitioner: what exactly is being injected, who makes it, can you see the box and batch number, and are the needles and products single-use and sterile? Be wary of anyone who promises a specific outcome after one session. See our note on exosome treatments for the same questions.

Quick answers

Is PDRN really salmon DNA?

Mostly, yes: it's purified DNA fragments from salmon or trout. Some products use plant-derived versions instead.

Is PDRN better than hyaluronic acid?

They do different things, and for serums there's no good head-to-head evidence. Hyaluronic acid has years of research behind its hydrating effect.

Can I use PDRN with retinol?

Nothing suggests a conflict. If your skin is irritated by retinol, a calming serum may help, but don't expect PDRN to cancel the irritation.