PDRN — polydeoxyribonucleotide — is a mixture of DNA fragments, most commonly extracted from salmon or trout gonadal tissue, used in wound healing and aesthetic medicine. It is not a peptide. It appears in this formulary because it is used alongside peptides in regenerative and aesthetic practice, and because its regulatory position in the United States differs sharply from its status elsewhere.
This guide situates PDRN within the broader field of peptide therapy and is written for clinicians. It is clinical education, not medical advice, and nothing here should be read as a treatment recommendation or protocol.
What is PDRN?
PDRN is a preparation of DNA fragments of defined molecular weight range, purified from the gonadal tissue of salmonid fish. The choice of source is deliberate: fish DNA is highly conserved with human DNA at the level of the nucleotide building blocks, and the purification process is designed to remove proteins and peptides that would otherwise pose an immunogenic risk.
It is worth stating clearly that PDRN is not a peptide and does not act through peptide receptors. It is a nucleic acid preparation with an unusually well-defined pharmacologic target for a product of its type.
How PDRN works
PDRN has two proposed mechanisms, and unusually for this category, the primary one is specific and receptor-mediated.
The principal mechanism is agonism at the adenosine A2A receptor. A2A activation promotes angiogenesis through increased VEGF expression, stimulates fibroblast proliferation and collagen synthesis, and exerts anti-inflammatory effects by damping pro-inflammatory cytokine production. That combination — new vessel formation, matrix production, reduced inflammation — maps directly onto the requirements of tissue repair.
The secondary mechanism is the salvage pathway. Degradation of the polynucleotides supplies nucleosides and nucleotides that cells can reuse for DNA and RNA synthesis, sparing the energetically expensive de novo route. In tissue that is actively proliferating to repair itself, that substrate supply is plausibly useful.
Having a named receptor is a meaningful distinction from many products in the regenerative category, where the mechanism is often described only in general terms.
How it is used internationally
PDRN has been used in Europe and in Korea for a considerable period, with regulatory approvals in various jurisdictions covering indications including diabetic foot ulcers and other difficult wounds, where the published literature is strongest.
In aesthetic medicine, polynucleotide products — marketed under names including Rejuran and others — are injected intradermally for skin quality, hydration and texture, with substantial popularity in Korean aesthetic practice and growing use elsewhere. Ophthalmic applications for dry eye have also been studied.
The evidence base is more substantial than for many compounds in this formulary, particularly in wound healing, though much of it comes from specific regions and study quality varies. It is not equivalent to a large multicentre trial program, and cross-jurisdiction approval is not FDA approval.
The real concentrations, product by product
Concentration is where most PDRN and polynucleotide discussion goes wrong, because the figures are quoted without the denominator. The table below is taught by Francisco Hernández, MD in Empire’s peptide certification, from the published product literature.
| Product | Active and concentration | Volume | Technique | Sessions |
|---|---|---|---|---|
| Placentex (Italy, a drug) | PDRN 5.625 mg per 3 mL ampoule, so 1.875 mg per mL | One 3 mL ampoule | Intramuscular, with perilesional use | Per indication |
| Plinest | Polynucleotide HPT 40 mg per 2 mL, so 20 mg per mL | 2 mL | Intradermal microdroplet and linear retrograde, 30 to 32 gauge | 3, or 4 for advanced aging, every 14 or 21 days |
| Plinest Eye | Polynucleotide HPT 15 mg per 2 mL, so 7.5 mg per mL | 1 to 2 mL, about 1 mL per side | Intradermal, needle or 27 gauge cannula | 3 to 4, every 14 to 21 days |
| Rejuran (Korea) | Polynucleotide 20 mg per mL | Up to 1 mL per side | Superficial dermis, serial puncture, 32 to 33 gauge | 3, two weeks apart |
Do not read that column as a potency ranking. These are different fractions, different routes and different indications. A 20 mg per mL gel is not ten times a 1.875 mg per mL drug, and comparing the numbers as though they were interchangeable is the second most common error after the denominator itself.
Sources: Romagnuolo M et al., Biomedicines 2023;11(4):1190 (PMID 37189808); Cavallini M et al., J Cosmet Dermatol 2021;20(3):922–928 (PMID 32799391).
United States regulatory status
PDRN is not FDA-approved as a drug in the United States. Products containing polynucleotides marketed for injection to alter skin structure or function fall within the FDA's drug and device frameworks, and lacking approval, their promotion and use for those purposes is not authorized.
This creates a familiar and genuine confusion. A clinician may encounter credible published research and legitimate international approvals, and reasonably conclude the product is established — which it is, in those jurisdictions. The regulatory position in the United States is a separate question with a separate answer.
Providers should be clear on that distinction before offering these products, and should verify status directly rather than relying on distributor representations. Our peptide formulary tracks status for every agent in the curriculum.
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