PDRN vs polynucleotide vs exosome: three regenerative ingredients, explained side by side

Key facts

The three ingredients at a glance

• PDRN: shorter salmon DNA fragments, first used as a wound-healing medicine; also found in skincare as c-PDRN.
• PN: longer salmon DNA chains, used mainly as injectable skin boosters given by a doctor.
• Exosomes: cell-released vesicles carrying proteins and RNA; sources and purity vary widely between products.
• Large molecules pass intact skin poorly, so topical products work nearer the surface than injections.
• None of the three is a filler: they aim at skin quality, not volume or lift.
• At SkinRev Lab: injected PN by Dr Sin Yong; needle-free c-PDRN facial by Aesthetic Therapists; no exosome treatments.

Side by side

PDRN, PN and exosomes compared

This is a general comparison. Products under the same label can differ in concentration, purity and intended use, so ask what is actually being used.

PDRN and PN

Same source, different chain length

PDRN is a mixture of DNA fragments purified from the sperm DNA of salmon trout or chum salmon, with active proteins removed. Laboratory and animal work suggests it acts mainly through adenosine A2A receptors, which are involved in tissue repair and calming inflammation, and that it supplies nucleotides cells can recycle. It was used for wounds and diabetic foot ulcers before aesthetics.

For years PDRN and PN have been used for products of very different lengths. A 2025 review proposed a cut-off at 1,500 kDa: PDRN for shorter chains, PN for longer ones. The authors note it is a proposal, not a regulatory rule, so a label alone does not tell you the chain length, concentration or route.

Route matters more than the name. Intact skin keeps out most molecules larger than about 500 daltons, and DNA fragments are far larger, so a cream or facial works closer to the surface and more gently than an injection. The clinical studies of PN used injections.

Exosomes

Exosomes: early evidence and unclear products

Exosomes are extracellular vesicles, far smaller than a cell, that carry signalling molecules between cells. Aesthetic products may be made from human mesenchymal stem cells grown in culture, from plants (often called exosome-like vesicles) or from animal sources, and isolation methods vary. Two products labelled exosomes may have little in common.

A 2025 systematic review of stem-cell-derived exosomes for scars, ageing and pigmentation found six human studies with 99 participants. Results were promising, but the authors called the evidence preliminary because of small samples, mixed designs and short follow-up. Because exosomes are usually applied after microneedling or laser, it is also hard to separate their effect from the procedure.

In Singapore, HSA publishes the ASEAN Cosmetic Directive list of substances that must not be in cosmetics; entry 416 is cells, tissues or products of human origin. HSA also states that notifying a cosmetic does not mean it is approved. The US FDA says there are currently no FDA-approved exosome products.

Who should wait

Who this is not suitable for

These cautions apply to injected PN and to any regenerative product placed into the skin.

• Pregnancy or breastfeeding: skin boosters are not advised.
• Fish or seafood allergy: tell the doctor before PN or PDRN is used.
• Active infection, cold sores, a rash or broken skin in the area.
• Autoimmune disease, keloid tendency, blood thinners or a bleeding tendency: discuss first.
• Anyone offered a product whose source, registration or intended use cannot be explained clearly.
• If you want lifting, volume or scar levelling, none of these ingredients alone will do it.

At SkinRev Lab

What SkinRev Lab offers instead

Injected polynucleotide boosters, including Rejuran Healer, are performed by Dr Sin Yong, MBBS (Singapore), MRCS (Edinburgh), MSc Practical Dermatology (Cardiff), at SkinRev Lab, #B1-28 CityLink Mall, 1 Raffles Link, linked underground to City Hall and Esplanade MRT, open daily 11am to 8pm, and at IN Eternity Clinic, Pacific Plaza, priced at consultation.

The Rejuran PDRN Facial is a non-medical facial by Aesthetic Therapists that applies cosmetic-grade c-PDRN with Meso Touch transdermal technology, no needles, in 60, 75 or 90-minute sessions. The Needleless SkinBooster is another needle-free option for hydration and tone.

SkinRev Lab does not offer exosome facials or exosome injections. If you have been offered one elsewhere, ask what the product is, where it comes from and how it is registered. WhatsApp +65 8266 9585 to book an assessment.

Sources

References & sources

1. Squadrito F, Bitto A, Irrera N, et al. Pharmacological activity and clinical use of PDRN. Front Pharmacol. 2017;8:224. doi:10.3389/fphar.2017.00224
2. Marques C, Porcello A, Cerrano M, et al. From polydeoxyribonucleotides (PDRNs) to polynucleotides (PNs): bridging the gap between scientific definitions, molecular insights, and clinical applications of multifunctional biomolecules. Biomolecules. 2025;15(1):148. doi:10.3390/biom15010148
3. Lampridou S, Bassett S, Cavallini M, Christopoulos G. The effectiveness of polynucleotides in esthetic medicine: a systematic review. J Cosmet Dermatol. 2025;24(2):e16721. doi:10.1111/jocd.16721
4. Al Shammrie FF, Alhemshy LZ, Althawy MM, et al. The efficacy of MSC-derived exosome-based therapies in treating scars, aging and hyperpigmentation: a systematic review of human clinical outcomes. Reports (MDPI). 2025;8(4):268. doi:10.3390/reports8040268
5. Bos JD, Meinardi MM. The 500 Dalton rule for the skin penetration of chemical compounds and drugs. Exp Dermatol. 2000;9(3):165-169. doi:10.1034/j.1600-0625.2000.009003165.x
6. Health Sciences Authority. Annexes of the ASEAN Cosmetic Directive (updated January 2023). Annex II, entry 416: cells, tissues or products of human origin.
7. Health Sciences Authority. How cosmetic products are regulated by HSA.
8. US Food and Drug Administration. Consumer alert on regenerative medicine products including stem cells and exosomes. 22 July 2020, content current as of 9 April 2024.

Common questions

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