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Salmon DNA in Skincare: What PDRN and PN Actually Mean on the Label
Salmon DNA sounds like something out of a film. On a skincare label it means one specific thing, and once you know what, the rest of the label gets a good deal easier to read.
Salmon DNA is PDRN
They are two names for one ingredient. PDRN, polydeoxyribonucleotide, is DNA cut into short pieces, and the DNA is taken from salmon or trout. Salmon DNA is the front of the box version. PDRN is the version people who read ingredient lists use. On the list itself it usually appears as sodium DNA or simply as DNA, which is the third name for the same thing and the one that trips people up.
Why the fish
Because the DNA can be taken from salmon in quantity and purified reliably, and the industry that first used the ingredient settled on that source. After purification it is a set of DNA fragments with the proteins and other material removed. It is no longer fish in any sense you could smell, taste or feel, and a serum with it in does not smell of the sea.
PDRN and PN
You will see both. PN stands for polynucleotide, and it is the same material cut into longer chains. PDRN is the shorter cut. Both come from the same source, both are large molecules that hold water, and both sit on the surface of skin when they are in a serum. The difference in chain length is real to a chemist. On the surface of your face, it is not a difference a cosmetic can honestly claim to show you, so do not pay extra for one over the other on the strength of the letters alone.
Is it vegan
No. It comes from an animal, so a PDRN serum is not vegan, and a label that says both PDRN and vegan on the same box is worth a question about where the DNA came from. If that matters to you, hyaluronic acid does the same water holding job on the surface and is usually made by fermentation rather than taken from anything.
If you have a fish allergy
Most fish allergies are to proteins in the fish, and the purification is meant to remove those. Nobody should take that on trust from a label. Ask a pharmacist before using a PDRN serum, patch test a small area behind the ear or on the inner arm first, and stop if anything stings, itches or reddens. Anyone seeing a doctor about their skin or about an allergy should ask them and follow that answer over this page.
Pink is a colour
A great many PDRN serums are pink, and the pink has become a kind of shorthand for the ingredient. It is a colour and not a measure. It tells you the shade of the serum and nothing about how much PDRN is in it or what it will do. Judge the bottle by its ingredient list and its verbs, not by its tint.
What the words do not tell you
How much PDRN is in the bottle, which labels rarely say. The order of the ingredient list is the honest clue, because lists run from most to least. What the serum will do for you, which is in the verbs: looks, appears and feels are appearance words a cosmetic may use, and words about changing your skin are not. And whether the bottle was tested, because a link to published research about an ingredient is research about the ingredient, not a test of that bottle.
What a PDRN serum can honestly promise
The look of plumper skin. The look of a smoother surface. Skin that looks and feels more hydrated while you use it. PDRN is a large molecule that holds water, and on the surface that is its job, the same job hyaluronic acid does. It is a real, ordinary, visible thing to buy. Anything past it, and any number attached to it, is the page selling harder than the ingredient can support.
Where Silka fits
Silka is a PDRN serum with a microneedle roller head on the bottle. Everything above applies to it: patch test first, ask a pharmacist first if fish is a problem for you, and expect the look of plumper, smoother, more hydrated skin while you keep it up and nothing further. We would rather say that plainly than borrow a word from a hospital.