You slept a full night, and the mirror still disagrees. The shadow under your eyes did not get the message, concealer only half hides it, and by now you have probably seen polynucleotides described as regeneration in a syringe. The interest is fair. The description is not, and the under-eye is the area where treating the wrong thing shows the most.
Do polynucleotides work under the eyes? For the quality of the skin itself, its thickness, texture and hydration, yes, modestly. In the only proper head-to-head study under the eye, they did about as well as a plain hyaluronic acid, and slightly better on texture. What they do not do is fill a hollow or lighten a pigment. So the real question is not whether they work, but which of the things an under-eye can be is the one troubling yours.
Start with the name, because it misleads. Polynucleotides are fragments of DNA, and calling an injection by that name makes people assume it repairs the DNA in their skin. It does not. What it actually does is more ordinary, and more useful, and worth understanding before you spend a few hundred pounds on it.
What polynucleotides are
They are long chains of purified DNA, usually taken from salmon or trout, cleaned of the proteins that would cause a reaction and cut to a set range of lengths. Injected into the skin, they are not read as genetic instructions. They work as a signal: they hold water in the tissue, mop up free radicals, and prompt fibroblasts, the cells that build and maintain the skin’s support structure, to work harder (systematic review, PMID 39645667). That mechanism comes from laboratory and animal studies; the human trials measure the result, not the pathway, so I keep it at that level.
In short: they signal the skin’s own cells and improve the tissue around them. They do not repair your DNA. The honest mechanism is the more interesting one anyway.
What that does to the skin
A fibroblast prompted this way behaves, for a while, like a younger and busier one: making more of the proteins that give skin its structure, and holding more water. On skin that suits it, that shows as an under-eye a little thicker, less crepey and better hydrated, so the tired, bluish look that comes from thin skin eases. It improves the quality of the skin, not its volume or its position. Nothing is filled and nothing is lifted.
Polynucleotides change the quality of the skin, not its shape. They will not fill a shadow, and no dose of them will.
The point that decides itWhat the under-eye evidence shows
Proven in people, modestly. The most relevant study is a 2022 randomised, double-blind, split-face trial: 27 people, three injections two weeks apart, polynucleotide on one side of the eye area and a plain (non-crosslinked) hyaluronic acid on the other (split-face RCT, PMID 32248707).
- On the overall aesthetic scores, there was no significant difference between the two sides.
- Polynucleotide did do better on two skin-quality measures, surface roughness and pore size, and held its improvement in elasticity and hydration a little longer.
- There were no serious side effects on either side.
So the result is real but modest: a small edge on skin texture over a treatment that was already doing something, in a small study. A 2025 systematic review of the wider evidence says much the same, consistent, well tolerated, and still waiting for the large, high-quality trials that would let anyone promise more (PMID 39645667). I would rather tell you that than pretend the evidence is stronger than it is.
Why an under-eye looks tired, and which part this treats
Before treating anything, this is the assessment that matters. “Dark circles” is not one thing. It is usually three, mixed in different amounts:
- A hollow or shadow, where the dip from lower lid to cheek has deepened and casts a shade. That is about structure and light, and it is treated, when it should be, with carefully placed filler, not by improving the skin.
- Pigment, real brown colouring in the skin, often inherited or from the sun. That needs a pigment treatment; polynucleotides do not lighten it.
- Thin, poor-quality skin, through which the muscle and vessels underneath show as a bluish tint, and which looks crepey on its own. This is the part polynucleotides genuinely help.
They treat the third, and only the third. Used on a shadow or a pigment, they will disappoint, which is how a good treatment gets a bad name. Much of the value of the consultation is simply working out, honestly, which of the three is doing the most on your face.
How long they last, and how many sessions
The effect builds over a short course rather than arriving in one visit, and it fades the same way. In the trial it was three sessions two weeks apart (PMID 32248707), which is close to how I do it: a course of three, two to three weeks apart, then a review, with a maintenance session after around six months. One session is a start, not the treatment. Any exact figure you are given for a single session is a guess. At Baudelaire, polynucleotides for the under-eye are £325 for a single session, or £875 for the course.
Polynucleotides are a safe, well-evidenced way to improve the quality of thin under-eye skin, sold under a name and a story that promise something else. Taken for what they are, they are worth having. Taken for what they are sold as, they are not.
I can improve the skin under your eye. I cannot turn a shadow into skin, and I would rather tell you that in the room than have you find out later.
