PDRN

Polydeoxyribonucleotide. It is a fragment of DNA, most often sourced from salmon, chosen because its structure is close enough to human DNA for skin to recognise it.

It started in medicine as a wound healing treatment, then moved into Korean skincare over the last few years. The interest is in repair rather than exfoliation or brightening.

You will also see it written as salmon DNA or polynucleotide. Same idea.

The research points at three things: calming inflammation, supporting the barrier and encouraging the skin to repair itself.

In practice people reach for it when skin is irritated, red or looking tired rather than when they want a dramatic change. It sits closer to a barrier cream than to a retinol in what it asks of your skin.

Most of the strong clinical evidence comes from injectable PDRN used in clinic. A topical version cannot do the same thing, so treat it as a gentle supporting ingredient, not a replacement for a procedure.

Pick the format that fits where your routine has a gap.

• Serum: Anua PDRN Hyaluronic Acid Capsule 100 Serum or SkinCeuticals Phyto Corrective with PDRN from Biotech Serum
• Something stronger: Medik8 Exo-PDRN Prismatic+ or Genosys Bio Meso PDRN Homecare Ampoule 5000
• Mask: Biodance Rejuvenating Caviar PDRN Real Deep Mask 4 Pack or COSRX PDRN Exosome Skinplaning Glaze Mask
• Moisturiser: Dr. Althea PDRN Reju 5000 Cream or Anua PDRN Hyaluronic Acid 100 Moisture Cream
• Toner or mist: COSRX 5 PDRN B5 Vital Soothing Toner or Purito Oat PDRN Gentle Refining Toner

If you only want one, make it a serum. That is where the concentration usually sits.

Yes, and this is one of PDRN's better qualities. It is calming rather than active, so it does not compete with your other steps.

A useful pattern is PDRN on the nights after a retinol night, to take the edge off the dryness. Or layer a PDRN serum under your moisturiser on any night.

The only thing to watch is layering too many serums at once. Three is usually where absorption stops improving and pilling starts.

PDRN is purified DNA rather than fish protein, and protein is what allergic reactions respond to. In principle that makes it low risk.

In practice, if you have a diagnosed fish or shellfish allergy, talk to your doctor before using it and patch test on your inner arm for a few days first.

Some brands now use plant derived or fermented alternatives if you would rather avoid it entirely.

Calming and comfort show up quickly, often within the first week. Skin feels less tight and looks less red.

Anything to do with firmness or texture needs eight to twelve weeks of consistent use, same as any repair focused ingredient.

It works best as a steady background step rather than something you reach for in a crisis.