The salmon DNA ingredient sold both as a clinic injection and as a serum. What it is, what the small body of research shows, why the two forms are not the same thing, and what 4 skincare experts said about it on camera.
Polynucleotides, and their close cousin PDRN, are the "salmon sperm" ingredient that has gone from Korean clinics to serums on every shelf. Is the serum the same thing as the injection? Can DNA from a fish really do anything for your skin? And is a pricey PDRN serum worth it?
First, a bit of untangling: two different things share this name, and the experts treat them differently. One is an injection given in a clinic, often under the eyes. The other is a serum or cream you put on at home. The warmer words in our index mostly go to the injections, while the topical serums draw the sharper doubts.
We went through 6 mentions of polynucleotides and PDRN from 4 skincare experts we track, among them a dermatologist and independent skincare reviewers. Together they give polynucleotides a Guru Score of 25%, a number held down mostly by those doubts about the serums. The research is small for the injections and thinner still for the serums [3, 4]. Below, what the experts said sits next to what the studies found, so you can see where the two line up.
Polynucleotides are purified fragments of DNA, usually from salmon or trout, used to support skin repair: as an injected "skin booster" in clinics and as an ingredient in serums. The experts we track are divided, and the serums draw most of the doubt. For the injections, small studies report smoother, firmer skin with mild side effects, but reviews rate the evidence as low to moderate quality [3, 4]. For serums on unbroken skin, there is very little human research, and the molecules are far larger than skin normally lets through [1, 8, 10].
| Question | What we found |
|---|---|
| What is it used for? | Skin quality: fine lines, firmness and thin skin under the eyes as an injection, and soothing or repair as a serum [2, 6]. |
| Do skincare experts recommend it? | They are divided. The serums draw sharper doubts than the injections. |
| Where does it come from? | Usually purified DNA from salmon or trout sperm. Plant-derived versions also exist, with much less research behind them [1, 11]. |
| Injection or serum? | Different things. The injections have small clinical studies; serums on intact skin have very little [3, 10]. |
| Is it a filler? | No. A review found hyaluronic acid filler better for restoring volume, with polynucleotides aimed at skin quality instead [6]. |
| Who should avoid it? | Anyone with a fish or shellfish allergy should raise it before treatment, as the usual source is fish [1, 14]. |
Polynucleotides are chains of DNA building blocks. In skincare and aesthetics the name usually means DNA fragments purified from the sperm of salmon or trout, which is where the "salmon sperm facial" nickname comes from [1]. You will see two names: PDRN (polydeoxyribonucleotide) and PN (polynucleotides). They come from the same kind of source, but a 2024 review describes them as distinct: PN has longer chains and a higher molecular weight than PDRN [2].
PDRN started out in medicine. It is a registered drug with tissue-repairing and anti-inflammatory effects, studied for wound healing, including diabetic foot ulcers [1]. Lab and animal studies suggest it works mainly by switching on a receptor called the adenosine A2A receptor, which calms inflammation and encourages repair, and by supplying building blocks that cells can recycle [1]. For PN, that same review notes there is no objective data on how it works; it is assumed to act like PDRN [2]. In aesthetics, the same idea is used to try to improve skin quality: firmness, elasticity and fine lines [3].
It is not the same as a peptide, even though it is often sold alongside them. Peptides are chains of amino acids; polynucleotides are chains of nucleotides, the units of DNA [1, 2].
Here is what each of these experts said on camera, with a link to the moment they said it.
You could put a Salmon sperm PDRN that will help with that. This is a soothing. It's not an active. [...] And so, it's great to use this kind of peptide post micro needling.Watch ▸
For me, I liked these products. I don't think that PDRN is bad at all. In fact, I really anticipate and await more published research on PDRN. [...] I went and spent a lot of money on these and I don't feel like I needed to.Watch ▸
At this point, PDRN in topical skin care products is theoretical. It's not based in any proven science.Watch ▸
Honestly, I so far I'm not overly impressed with it, but um I do need to do more testing on each of these, so I will report back.Watch ▸
With the verdicts split, the caveats are where the useful detail sits.
The research on the injections is real but small. A 2025 systematic review found 9 studies with 219 patients in total, rated them low to moderate quality, and found promising results for wrinkles, texture and elasticity, with mild, short-lived side effects. It called for rigorous, high-quality studies before firm conclusions [3]. Two of its authors declared ties to a company that makes or distributes polynucleotide injectables [3].
A 2026 review of randomised trials found 7 trials with 183 people across skin rejuvenation, scars and wound healing. The clearest benefit was in wound healing. Of the 4 rejuvenation trials, only one compared polynucleotides with an inactive treatment, and in that one the polynucleotides were applied to skin just treated with radiofrequency microneedling [4, 9]. No serious side effects were reported [4].
Head to head, a 2014 trial in 72 people found a polynucleotide injection did about as well as a hyaluronic acid filler on crow's feet, with no significant difference between the two [5]. Under the eyes, a 2026 review concluded that hyaluronic acid filler remains better for restoring volume, while polynucleotides improve skin quality measures such as elasticity and fine lines, and said differences between studies prevent definitive conclusions [6]. Much of the under-eye evidence is observational: one 2026 study of 42 patients found people rated their under-eyes better after injections, but it had no comparison group [7].
Experts outside our index are cautious too. A 2024 review found studies reporting improvements, others reporting limited or no benefit, and said more research is needed to understand how polynucleotides work and how best to use them [2].
No, and this is the most useful thing to know before you spend money on either. Nearly all the clinical research is on polynucleotides placed into the skin: injected, or applied straight after a procedure such as microneedling that opens the skin [3, 4, 9].
Polynucleotide "skin boosters" are injected by a practitioner, usually as a course of three or four sessions two weeks apart in the studies [3, 5]. In the UK and EU they are sold as medical devices: the polynucleotide products used in the studies we read are CE-marked class III medical devices [12]. In the US, the FDA's page on approved dermal fillers lists hyaluronic acid, calcium hydroxylapatite, poly-L-lactic acid and PMMA, and polynucleotides are not among them [13]. If a clinic offers polynucleotide injections, ask exactly which product it is, and choose a qualified medical practitioner.
A serum has to get through the outer layer of your skin, which keeps out most molecules much bigger than about 500 daltons [8]. PDRN is measured in kilodaltons, from 50,000 daltons upwards [1], so getting it through intact skin is the open question. Even researchers developing a topical PDRN describe how it is delivered into skin as insufficiently defined [10].
Human evidence for leave-on PDRN products is very thin. We found one small randomised trial of a PDRN eye cream on unbroken skin: 31 women for 28 days, compared against a retinol eye cream rather than a plain cream [10]. Plant-based PDRN, now common in serums, is mostly backed by lab work, and a 2026 review warns against treating it as equivalent to the fish-derived kind [11].
In the studies, side effects from injections were mostly mild and short-lived, such as swelling, redness, bruising or itching where the needle went in [3], and no serious treatment-related side effects were reported in the randomised trials reviewed in 2026 [4]. Those trials were small and short, so rare or long-term problems would not show up yet [4].
Most polynucleotides come from salmon or trout [1]. A 2026 paper on choosing skin boosters lists fish or shellfish allergy among the first things a practitioner should screen for with fish-derived products [14]. Tell your practitioner about any fish allergy, and check the label of a serum if you react to fish.
There is no good evidence either way. Clinical studies of polynucleotide injections exclude people who are pregnant or breastfeeding [7, 12], so ask your doctor or midwife before using them.
It depends which form you mean. Injections are a clinic treatment, not a routine step, and the course and spacing are set by your practitioner; the studies we read mostly used three or four sessions two weeks apart [3, 5]. For a serum, the usual skincare rules apply.
Cleanse, apply the serum, then moisturiser, then sunscreen in the morning. PDRN serums are usually sold as soothing, hydrating products, so they sit easily in either routine.
This is where the experts who like it reach for it, and it is closest to how the research uses it [4, 9]. Follow your practitioner's aftercare instructions first. Freshly treated skin absorbs whatever you put on it, so only use a product they are happy with.
A serum is not a substitute for the injection, and neither is a substitute for daily sunscreen and a proven active such as a retinoid. Our retinol guide covers the anti-ageing step with the most evidence.
PDRN serums are gentle and do not exfoliate, so they pair easily. The usual rule still applies: add one new product at a time, so you can tell what your skin is reacting to.
A common pairing, both in clinics and in serums. Several injectables combine the two, including the one used in a 2026 acne scar study [12]. In a serum, both are there to hydrate.
We found no trial of the two used together on the skin. Retinol has far more evidence for ageing skin, so if you can only pick one active, pick that. A gentle PDRN serum can sit in the same routine once your skin has settled into retinol.
Often sold together, and neither exfoliates. They are different things: peptides are made of amino acids, polynucleotides of DNA [1, 2]. Our peptides guide covers what the experts say about them.
Polynucleotides are purified fragments of DNA, usually from salmon or trout sperm, used to support skin repair [1]. They are injected in clinics as a "skin booster" and added to serums and creams. The experts we track are divided, with the sharper doubts aimed at the serums.
Both are purified DNA fragments from the same kind of fish source, and the names are often used loosely. A 2024 review describes them as distinct, with PN made of longer, heavier DNA chains [2]. PDRN is also a registered drug, studied for wound healing [1]. On a skincare label, either name tells you little about how much is in the bottle or whether it reaches your skin.
Small studies suggest a modest improvement in skin quality, such as fine lines, texture and elasticity [3]. A 2025 systematic review found 9 studies with 219 patients, rated low to moderate quality, and called for better research [3]. One trial found them about as good as a hyaluronic acid filler on crow's feet [5]. Promising, but not proven.
There is very little evidence that they do on unbroken skin. PDRN molecules are far larger than the roughly 500 dalton size that skin normally lets through [1, 8], and we found one small trial of a PDRN eye cream, in 31 women over 28 days [10]. Dr Dray calls topical PDRN theoretical. A PDRN serum may still be a pleasant, gentle product.
They do a different job. A 2026 review found hyaluronic acid filler better for restoring lost volume under the eyes, while polynucleotides improved skin quality, such as elasticity and fine lines, with a favourable safety record [6]. Which suits you is a question for a qualified practitioner.
We found no FDA approval for a polynucleotide injectable. The FDA's page on approved dermal fillers lists hyaluronic acid, calcium hydroxylapatite, poly-L-lactic acid and PMMA, and polynucleotides are not among them [13]. In the UK and EU, the injectables are sold as CE-marked medical devices [12]. Serums are sold as cosmetics, which do not need approval to make the claims on the box.
Talk to your practitioner first. Most polynucleotides are purified from salmon or trout DNA [1], and a 2026 paper on choosing skin boosters lists fish or shellfish allergy as something to screen for before using fish-derived products [14]. Plant-based versions exist, though they have much less research behind them [11].
There is no good evidence either way, so ask your doctor or midwife first. Clinical studies of polynucleotide injections exclude people who are pregnant or breastfeeding [7, 12], which means nobody has measured how safe they are then. Most people would wait until after pregnancy for an elective injection.
In studies, they were mostly mild and short-lived, such as redness, swelling or bruising at the injection site [3]. A 2026 review of randomised trials found no serious treatment-related side effects [4]. The trials were small and short, so rare or long-term effects could still be missed. Choose a qualified medical practitioner.
Studies usually give a course of three or four sessions two weeks apart, rather than a single treatment [3, 5], and results are judged over months. Your practitioner sets the exact plan.
This is where the experts who like PDRN use it. Darnell Cox layers a salmon PDRN product after microneedling as a soother. It is also closest to how the research uses it: one trial applied polynucleotides to skin just treated with radiofrequency microneedling and found wrinkles improved faster on that side [9]. Follow your practitioner's aftercare first.
No. PDRN is made of DNA fragments, chains of nucleotides, while peptides are chains of amino acids [1, 2]. They are often sold in the same serums and described the same way, as soothing or repairing, but they are different molecules. Our peptides guide covers what the experts say about peptides.
They are divided. Darnell Cox likes PDRN after microneedling, AliceintheRabbitHole liked her PDRN serums but felt they were not worth the money, and Dr Dray calls topical PDRN theoretical.
4 experts, 6 mentions, every one traced to a video you can watch. Sponsored takes are excluded.
This guide combines two kinds of information. The expert consensus comes from 6 mentions of polynucleotides and PDRN by 4 skincare experts in their YouTube videos. Each one was read, given a Yay, Mixed or Nay verdict and linked to the moment it was said. Sponsored takes are excluded. The research sections summarise published studies and medical sources, listed in full above.
The Guru Score measures how warmly the experts talk about polynucleotides. It is not a measure of clinical effectiveness, and this guide is not medical advice. It has not been reviewed by a doctor.
This guide is general information, not medical advice. The Guru Score reflects how warmly the experts we track talk about polynucleotides; it is not a measure of clinical efficacy. Speak to a dermatologist or doctor about a diagnosed skin condition, and before using any medicine.