Evidence register
Every evidence verdict published on this site, grouped by verdict and ordered from strongest to weakest. Published so that the whole set can be read at once, and so that revisions are visible rather than quiet.
An evidence note states a claim in the form it is usually made, says what kind of evidence would settle it, says what kind exists, and gives a verdict from a fixed vocabulary of seven terms. No verdict contains a number. The vocabulary is defined in full on the editorial standards page.
Nothing on this site is graded favourably because it is popular, and nothing is graded unfavourably because we are sceptical of the category. Several verdicts here are deliberately directed at claims that would suit our own editorial position if they were true, and they are graded on the same basis as the rest.
Established
Repeatedly demonstrated in independent human studies of a design capable of showing it, and not seriously disputed.
A prescriber must personally assess a patient before prescribing injectable cosmetic medicines.
Advertisers must hold evidence for objective claims before making them.
EstablishedSection 5.4, What may lawfully be claimed
Advertising cosmetic interventions to under eighteens is prohibited.
EstablishedSection 5.5, Under eighteens and the law
Consent is a process of dialogue rather than a signature on a form.
Valid consent requires more than a signed form.
EstablishedSection 6.2, What good consent looks like
The person performing the procedure is responsible for the consent discussion.
EstablishedSection 6.2, What good consent looks like
Sun protection improves the long term appearance of skin.
EstablishedSection 6.6, Deciding not to
Supported, with caveats
Human evidence points this way, but the studies are few, small, short, industry funded, or measured something adjacent to the claim.
The material is fully broken down and nothing remains in the tissue in the long term.
Supported, with caveatsSection 1.1, What polynucleotides actually are
Most of the risk of this treatment comes from the act of injecting rather than from the material.
Supported, with caveatsSection 4.4, Risks that come from injecting
Filler placed in the area years ago remains relevant to a decision today.
Supported, with caveatsSection 4.6, The history that should change the plan
Plausible but unsettled
There is a reasonable biological argument and some human signal, and the question has not been answered by a study capable of answering it.
Polynucleotide injectables work by supplying DNA that the skin uses to repair itself.
Plausible but unsettledSection 1.1, What polynucleotides actually are
A polynucleotide result outlasts the material because it changes what the cells are doing.
Plausible but unsettledSection 1.5, How it differs from hyaluronic acid
Injected polynucleotides act on adenosine receptors in human skin to change cell behaviour.
Plausible but unsettledSection 2.1, The claimed mechanism, step by step
Laboratory evidence that polynucleotides stimulate fibroblasts supports the cosmetic use of the treatment.
Plausible but unsettledSection 2.6, Laboratory findings and people
Avoiding exercise, alcohol and heat after treatment reduces bruising and swelling.
Plausible but unsettledSection 3.5, Aftercare, sorted by reason
Autoimmune conditions are a contraindication to this treatment.
Plausible but unsettledSection 4.1, Who is a poor candidate
Thinly evidenced
The claim circulates widely and rests on a small, weak or indirect body of work that would not support it if read strictly.
Purification removes fish protein to the point that the product is safe for people with fish allergy.
Thinly evidencedSection 1.2, Where the material comes from
Complications from polynucleotide treatment are rare.
Thinly evidencedSection 1.4, Marketing category, regulatory category
There is good evidence that polynucleotide treatment improves skin quality.
Thinly evidencedSection 2.2, The shape of the evidence
Patient satisfaction scores demonstrate that a cosmetic treatment is effective.
Thinly evidencedSection 2.4, Reading a study a clinic quotes at you
Maintenance sessions are required to preserve the result.
Thinly evidencedSection 3.1, What a course actually involves
Polynucleotide scalp injections treat hair loss.
Thinly evidencedSection 3.2, Treatment areas, and why they differ
Bruising can be prevented by stopping supplements before treatment.
Thinly evidencedSection 3.4, What recovery genuinely looks like
The product is safe for people with fish allergy because purification removes fish protein.
Thinly evidencedSection 4.3, Fish sourcing and allergy
Contested
Competent people who have read the same material disagree, and the disagreement is not resolved by the published record.
Research on PDRN supports the use of PN products in facial skin.
ContestedSection 1.3, PN and PDRN are not the same abbreviation
Withholding figures makes a reference less useful.
The 2021 Act does not apply to polynucleotide injections because they are not fillers.
Not established
The evidence needed to support the claim has not been produced. This is not the same as the claim being false.
Longer chain polynucleotide preparations produce better cosmetic results than shorter chain preparations.
Not establishedSection 1.3, PN and PDRN are not the same abbreviation
Polynucleotides improve skin quality in a way that hyaluronic acid skin boosters cannot.
Not establishedSection 1.5, How it differs from hyaluronic acid
A practitioner's confidence about a product indicates that the product is well supported.
Not establishedSection 1.6, Reading the product
A UK clinic will always be able to show you the product packaging.
Not establishedSection 1.6, Reading the product
The improvement outlasts the injected material because the tissue itself has changed.
Not establishedSection 2.1, The claimed mechanism, step by step
The absence of strong evidence means the treatment does not work.
Not establishedSection 2.2, The shape of the evidence
The question of whether the effect persists after clearance has been answered.
Not establishedSection 2.3, What is not known
Anyone can currently state a complication rate for this treatment in the United Kingdom.
Not establishedSection 2.3, What is not known
A published study supporting a treatment means the treatment is supported.
Not establishedSection 2.4, Reading a study a clinic quotes at you
A substance that accelerates wound healing will improve the appearance of intact skin.
Not establishedSection 2.6, Laboratory findings and people
The recommended number of sessions and interval between them is the optimal schedule.
Not establishedSection 3.1, What a course actually involves
Polynucleotide treatment improves the appearance of the backs of the hands.
Not establishedSection 3.2, Treatment areas, and why they differ
Polynucleotide treatment improves under eye hollowing and dark circles.
Not establishedSection 3.3, The under eye area
Prolonged swelling in the periorbital area after this treatment is rare.
Not establishedSection 3.3, The under eye area
Aftercare instructions are standardised across the sector.
Not establishedSection 3.5, Aftercare, sorted by reason
Stopping polynucleotide treatment leaves the skin worse than before it started.
Not establishedSection 3.6, What happens when you stop
Repeated courses over many years are safe.
Not establishedSection 3.6, What happens when you stop
Polynucleotide treatment is unsafe in pregnancy.
Not establishedSection 4.1, Who is a poor candidate
Complications from this treatment are very rare.
Not establishedSection 4.2, Effects, side effects, complications
Absence of reported allergic reactions shows the product does not cause them.
Not establishedSection 4.3, Fish sourcing and allergy
Premises offering injectable cosmetic treatment in England are inspected.
Not establishedSection 4.4, Risks that come from injecting
Cosmetic complications should be managed by the clinic that caused them.
Not establishedSection 4.5, If something goes wrong
Every practitioner offering these treatments is answerable to a professional regulator.
Not establishedSection 4.5, If something goes wrong
A completed medical history form makes a treatment safe.
Not establishedSection 4.6, The history that should change the plan
Only medically qualified people may inject cosmetic injectables in the UK.
Not establishedSection 5.1, Who may legally inject
A practitioner on a healthcare register is necessarily more skilled at this procedure.
Not establishedSection 5.1, Who may legally inject
Non surgical cosmetic procedures in England are now licensed.
Not establishedSection 5.2, The licensing power, and its status
The sector is entirely unregulated.
Not establishedSection 5.2, The licensing power, and its status
Polynucleotide treatment requires a prescription.
Not establishedSection 5.3, Prescribing and remote prescribing
Clinic advertising claims for this treatment have been assessed by a regulator.
Not establishedSection 5.4, What may lawfully be claimed
All clinics offering injectable cosmetic treatment are inspected.
Not establishedSection 5.6, Premises, indemnity and redress
Every practitioner offering this treatment carries indemnity insurance.
Not establishedSection 5.6, Premises, indemnity and redress
A free consultation is equivalent to a paid one.
Not establishedSection 6.1, What a consultation should cover
A practitioner who answers questions confidently is well informed.
Not establishedSection 6.3, Questions marketing copy cannot answer
Asking questions damages the relationship with a practitioner.
Not establishedSection 6.3, Questions marketing copy cannot answer
One of these treatments is better than the others.
Not establishedSection 6.4, Comparing the regenerative injectables
A course purchased as a package is better value than paying session by session.
Not establishedSection 6.5, Cost, without a price list
Marketing claim only
The statement originates in promotional material and has no published clinical support that we can locate.
Salmon DNA is uniquely compatible with human skin.
Marketing claim onlySection 1.2, Where the material comes from
The product is approved, and therefore the treatment is proven to work.
Marketing claim onlySection 1.4, Marketing category, regulatory category
Figures quoted for how long polynucleotide results last are based on measurement.
Marketing claim onlySection 2.5, Why we publish no numbers
Polynucleotide treatment involves no downtime.
Marketing claim onlySection 3.4, What recovery genuinely looks like
Because polynucleotides are naturally derived, they carry less risk than synthetic injectables.
Marketing claim onlySection 4.2, Effects, side effects, complications
Regenerative injectables are a coherent treatment category.
Marketing claim onlySection 6.4, Comparing the regenerative injectables
Cosmetic treatment is an investment.
Marketing claim onlySection 6.5, Cost, without a price list
Not having cosmetic treatment carries a cost, because ageing continues.
Marketing claim onlySection 6.6, Deciding not to
Revisions to this document
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