Clinical education article · Updated March 2026 · 9 min read · For licensed medical aesthetics practitioners
For US medical aesthetics practitioners, PDRN and polynucleotides (PN) are among the most clinically significant molecules to enter the regenerative space since collagen biostimulators. Yet in the US market, the science separating these two molecules is rarely covered in depth — leaving many practitioners to navigate product selection based on marketing materials rather than peer-reviewed data.
Interest has been building steadily, partly driven by the global success of PDRN-based products from South Korea — notably Rejuran — and partly by the arrival of established European PN formulations from manufacturers like Mastelli, Croma-Pharma and Promoitalia, all produced under rigorous EU MDR 2017/745 regulatory standards. What practitioners often lack is a clear, evidence-based framework for distinguishing the two: when to choose one over the other, how to structure rational injection protocols, and what the clinical data actually support.
This article provides that framework. It covers the molecular biology, receptor mechanisms, clinical indications and protocol design for both PN and PDRN — with product links to the Fräya Med Supply US store, which offers certified European PN products to licensed US practitioners.
Bottom line for US practitioners: PDRN and polynucleotides (PN) share the same chemical backbone and both activate the adenosine A2A receptor. The difference is molecular weight: PDRN (< 1500 kDa) binds the receptor faster with stronger anti-inflammatory and tissue-repair effects; PN (≥ 1500 kDa) builds a sustained dermal scaffold with stronger long-term ECM remodeling. Think of it this way: if collagen biostimulators (Sculptra, Radiesse) address volume and structural lift over time, PN/PDRN address skin quality and cellular regeneration — a different deficit, a different mechanism, an equally evidence-based intervention.
What Are Polynucleotides (PN)?
Polynucleotides (PN) are long-chain deoxyribonucleotide polymers with a molecular weight of ≥ 1500 kDa, extracted from fish gonads — primarily trout (Mastelli, Croma-Pharma) or salmon (Promoitalia). Their high molecular weight gives them greater viscoelasticity and allows them to form a three-dimensional porous scaffold within the dermis, supporting extracellular matrix (ECM) remodeling over a multi-session treatment course.[1]
In the US market, the term ‘PN product’ has become broadly used — but this covers a spectrum. Some products contain high-MW fractions exclusively; others contain mixed PN/PDRN fractions. Always consult the product IFU for reported molecular weight data before making a clinical selection.
What Is PDRN?
PDRN (polydeoxynucleotides) are shorter-chain deoxyribonucleotide fragments with a molecular weight below 1500 kDa, typically derived from salmon sperm cells (Oncorhynchus keta, O. mykiss). Their lower molecular weight produces faster tissue diffusion, higher enzymatic stability, and stronger affinity for the adenosine A2A receptor — driving a more pronounced anti-inflammatory and tissue-repair response.[2]
US practitioners are most likely to recognize PDRN through Korean products such as Rejuran, which has been well studied in the South Korean and Asian aesthetic markets. European-manufactured formulations now bring the same molecular category to the US under CE/MDR certified quality standards.
Mechanism of Action: One Receptor, Two Clinical Profiles
The most common misconception in PN/PDRN education is the assumption that they operate through entirely different biological pathways. In reality, both PN and PDRN activate the adenosine A2A receptor — present on fibroblasts, endothelial cells and keratinocytes. The distinction lies in receptor kinetics and the downstream cascade that predominates, determined by molecular weight.[2][4]
A2A Receptor Activation: Documented Downstream Effects
When deoxyribonucleotide metabolites engage the A2A receptor, the following effects have been documented across peer-reviewed studies:[2][4]
• NF-κB and MAPK signaling inhibition — downregulation of pro-inflammatory cytokines TNF-α and IL-6
• Intracellular cAMP elevation — anti-apoptotic and anti-inflammatory cellular response
• VEGF upregulation — neovascularization and improved microvascular perfusion
• MMP-1 downregulation — reduced collagenase activity, preservation of existing collagen
• Fibroblast proliferation and activation — collagen type I and III synthesis, ECM remodeling
How Molecular Weight Shapes the Clinical Outcome
PDRN (lower MW) engages the A2A receptor faster and more efficiently. Its dominant clinical expression is tissue repair, inflammation control and accelerated healing — making it the rational choice for post-procedure recovery, wound healing contexts and conditions with an active inflammatory component.[2]
PN (higher MW) produces a sustained scaffolding effect in the dermis, with stronger emphasis on long-term fibroblast activation and structural ECM remodeling. Results build progressively across a treatment series rather than manifesting acutely.[1]
The Salvage Pathway: A Second Mechanism of Action
Both molecules also contribute nucleotide precursors through the salvage pathway: exogenous DNA fragments are degraded by tissue nucleases; the released purine and pyrimidine bases re-enter cellular nucleotide synthesis, supporting DNA repair and cell proliferation. This mechanism is particularly relevant in post-ablative and damaged skin contexts where cellular repair demand is elevated.[5]
PN vs PDRN: Side-by-Side Clinical Reference
The following table summarizes clinically relevant differences. Note that the mechanism column reflects shared A2A receptor activation with distinct kinetics and downstream emphasis — not two fundamentally separate pathways.[1][2][4]
| Parameter | Polynucleotides (PN) | PDRN |
| Molecular weight | ≥ 1500 kDa | < 1500 kDa |
| Receptor | Adenosine A2A (slower kinetics, sustained scaffold) | Adenosine A2A (faster kinetics, higher receptor affinity) |
| Dominant downstream effect | ECM remodeling, fibroblast proliferation, collagen synthesis | Tissue repair, anti-inflammatory, microcirculation (VEGF) |
| Dermal behavior | 3D scaffold formation — longer tissue residence | Rapid diffusion — faster onset, quicker clearance |
| Best clinical fit | Chronic photo-aging, skin quality loss, structural density, long-term regeneration | Post-procedure healing, active inflammation, alopecia, acute repair |
| Typical protocol | 3–4 sessions every 2–3 weeks; maintenance every 4–8 weeks | 3–4 sessions; intervals vary by indication |
| Regulatory standard | CE/MDR certified (EU MDR 2017/745) | CE/MDR certified (EU MDR 2017/745) |
Clinical Indications: Matching the Molecule to the Patient
Photo-Aging and Chronic Skin Quality Loss
The most common presentation in US aesthetic offices: reduced dermal density, loss of radiance and textural irregularity without a clear volumetric deficit. PN-dominant products address this through sustained fibroblast activation and ECM scaffolding. Results build across 3–4 sessions before measurable structural improvement is visible — practitioners should set appropriate patient expectations upfront.[1]
Post-Ablative and Post-Procedure Recovery
After ablative laser, fractional RF or aggressive chemical peel, the tissue is primed for repair but vulnerable to prolonged inflammation. PDRN’s faster A2A receptor engagement and NF-κB inhibition make it the rational choice here — supporting reduced erythema duration and accelerated re-epithelialization. Timing: begin 5–7 days post-procedure once initial re-epithelialization is confirmed.[4]
Acne Scarring and Structural Remodeling
Improving acne scars requires structural ECM remodeling — reducing dermal tethering, stimulating new collagen deposition, and improving surface regularity. Higher-MW PN formulations are well suited for this indication, particularly products designed for intensive regeneration such as Newest (Mastelli) and Nucleofill Strong 2.5%.
Androgenetic Alopecia
PN-based scalp therapy improves follicular microvascularization via VEGF upregulation and supports dermal papilla cell activity. Dedicated scalp formulations are administered via mesotherapy technique into superficial scalp layers. Clinical data support combination with PRP, showing superior hair shaft thickness improvement compared to PN monotherapy.[6]
Pre-Treatment Tissue Preparation
Running a PN series before introducing HA fillers or collagen biostimulators (Sculptra, Radiesse) optimizes the tissue substrate — improving hydration, cellular metabolism and vascularization. Practitioners familiar with the concept of tissue priming before volumetric procedures will find PN a rational evidence-based tool for this purpose.
Periorbital Rejuvenation
Dedicated low-viscosity periorbital formulations are designed for the specific demands of this anatomical zone — thinner skin, proximity to critical structures, and requirement for micro-papular technique. Dedicated products (Plinest Eye, PolyPhil Eye) are not interchangeable with full-face formulations.
Injection Protocols
Full-Face Skin Quality Protocol
• Sessions: 3–4 treatments at 2–3 week intervals
• Maintenance: 1 session every 4–8 weeks
• Technique: serial puncture (nappage), microdroplet or retrograde linear threading; mid-to-superficial dermis, 1.5–2 mm depth
• Products: Plinest / Plinest Fast | PolyPhil Next | Nucleofill Medium / Strong
Post-Laser / Post-Procedure Recovery Protocol
• Timing: begin 5–7 days post-procedure once re-epithelialization is confirmed
• Sessions: 3–4 treatments every 10–14 days
• Products: Newest (Mastelli) — intensive regeneration and tone/texture repair | Nucleofill Strong 2.5% — deep fibroblast stimulation
Periorbital Protocol
• Sessions: 3–4 every 10–14 days
• Technique: micro-papular, 0.2–0.5 cm spacing; dedicated low-viscosity formulations only
• Products: Plinest Eye | PolyPhil Eye
Scalp and Alopecia Protocol
• Sessions: 3–4 every 3–4 weeks
• Technique: mesotherapy into superficial scalp layers; 0.5 ml per injection point
• Combination with PRP: supported by clinical data — superior hair shaft thickness vs. PN alone[6]
• Products: Nucleofill Hair | PolyPhil Hair
Combination Protocols: PN + HA
When a patient presents with both skin quality loss and volume depletion, PN and HA fillers address both deficits within a single treatment plan. Three approaches:
• Sequential (preferred): complete the PN series first; introduce HA filler 2–3 weeks after the final PN session. The optimized tissue substrate typically yields a more natural, longer-lasting volumetric result.
• Same-session: both products in a single visit — PN in the superficial-to-mid dermis, HA in the appropriate plane for volume. Practical for patients with limited availability.
• Single hybrid product: Renefil is a hybrid PN + HA formulation — combining regenerative biostimulation and volumetric support in one injectable, for practitioners seeking a streamlined single-product approach.
PN + Biostimulator (Sculptra, Radiesse): PN series first — 2–3 sessions to prime tissue quality — biostimulator introduced 2–3 weeks later. PN optimizes cellular metabolism and hydration before the longer-acting biostimulant is placed, potentially supporting outcome quality and longevity.
PN & PDRN Products: Selection Guide for US Practitioners
All products below are manufactured by established European companies under EU MDR 2017/745, the most rigorous injectable medical device regulatory framework currently in effect. They are available to licensed US practitioners via Fräya Med Supply.
| Brand | Manufacturer | Products | Technology | Primary Indication |
| Nucleofill | Promoitalia, Italy | Medium (2%), Strong (2.5%), 25, Hair | Salmon DNA, HPT purification | Photo-aging, laxity, density loss, scalp/alopecia |
| Plinest | Mastelli, Italy | Plinest, Fast, Eye, Body, Newest | Trout DNA, PN-HPT™ | Full-face revitalization, acne scars, periorbital, post-ablative recovery |
| PolyPhil | Croma-Pharma, Austria | PolyPhil, Next, Eye, Hair | PN-HPT, EU MDR certified | All skin types and ages; periorbital; scalp — single EU-certified supplier |
| Renefil | Relife, Italy | Multiple viscosity variants | Hybrid PN + HA formulation | Simultaneous skin quality loss and volume depletion — PN + HA in one injectable |
Certified quality, professional access: All products are CE/MDR-certified medical devices manufactured under EU MDR 2017/745. Available exclusively to licensed medical aesthetics practitioners. Register at frayamedsupply.com to access the full catalog.
Frequently Asked Questions
What is the difference between PDRN and polynucleotides?
The core difference is molecular weight. PDRN (< 1500 kDa) has shorter chains that bind the adenosine A2A receptor faster, producing stronger anti-inflammatory and tissue-repair effects. Polynucleotides (PN, ≥ 1500 kDa) form a longer-lasting dermal scaffold with stronger fibroblast activation and ECM remodeling. Both molecules act through the same receptor — they are not mechanistically unrelated.[1][3]
Is Rejuran PDRN or polynucleotides?
Rejuran is a PDRN product — it uses salmon-derived polydeoxynucleotides with a reported MW typically below 1000 kDa. European products such as Nucleofill, Plinest and PolyPhil generally contain higher-MW PN fractions or mixed fractions. They are biologically related but clinically distinct. Always verify MW data in the product IFU before selecting for a specific indication.
Can PN be used before HA filler?
Yes, and it is a well-established combination approach. PN administered first optimizes the dermal substrate — improving hydration, vascularization and cellular metabolism — before HA is introduced. Sequential protocols (PN series → HA 2–3 weeks later) typically yield more natural and longer-lasting volumetric results. Renefil offers a hybrid PN + HA single-product option for simplified or same-session protocols.
What is the best PN product for post-laser skin recovery?
For post-ablative recovery, products with a strong regenerative and anti-inflammatory profile are preferred: Newest (Mastelli) for intensive structural repair, and Nucleofill Strong 2.5% for deep fibroblast stimulation. Begin treatment 5–7 days post-procedure once re-epithelialization is confirmed.[4]
Are these products CE/MDR certified?
Yes. All products available at Fräya Med Supply are CE-marked medical devices manufactured under EU MDR 2017/745 — the European Union’s most comprehensive regulatory framework for injectable medical devices. This certification requires documented clinical data, post-market surveillance, and rigorous quality management systems — providing a defined safety and efficacy standard for licensed practitioners.
How do polynucleotides work for hair loss?
PN scalp therapy works through two primary mechanisms: VEGF upregulation improves microvascular perfusion around the follicular unit, and A2A receptor activation supports dermal papilla cell activity. Dedicated scalp formulations (Nucleofill Hair, PolyPhil Hair) are administered via mesotherapy. Clinical data support combining PN with PRP for superior outcomes in androgenetic alopecia.[6]
References
[1] Cavallini M et al. Polynucleotides in aesthetic medicine: a review. J Cosmet Dermatol. 2023;22(3):732–740. doi:10.1111/jocd.15579
[2] Veronesi F et al. PDRN and VEGF stimulation in wound healing: experimental and clinical findings. Eur J Histochem. 2022;66(s1):3367. doi:10.4081/ejh.2022.3367
[3] Marques AP et al. Proposed nomenclature for polynucleotides and polydeoxynucleotides in aesthetic medicine: MW cut-off at 1500 kDa. J Cosmet Dermatol. 2025;24(2):e16123. doi:10.1111/jocd.16123
[4] Squadrito F et al. The role of the adenosine A2A receptor in PDRN pharmacology. Curr Pharm Des. 2020;26(7):757–764. doi:10.2174/1381612826666200213100004
[5] Lee SH et al. The salvage pathway of nucleotide synthesis and its role in deoxyribonucleotide therapy. Int J Mol Sci. 2021;22(9):4537. doi:10.3390/ijms22094537
[6] Gentile P et al. Effectiveness of PDRN and PRP in androgenetic alopecia: randomized controlled trial. Aesthet Plast Surg. 2023;47(4):1592–1601. doi:10.1007/s00266-022-03141-y
All references are peer-reviewed publications. Product information should be verified against current Instructions for Use prior to clinical application. Regulatory status of products in the United States should be confirmed by the practitioner prior to ordering or use.
Browse PN & PDRN products — licensed US practitioners: → Nucleofill range | → Plinest range | → PolyPhil range | → Renefil (PN + HA hybrid) |
frayamedsupply.com/us | contact@frayamedsupply.com
