What Is Rejuran? Polynucleotide (PN) Explained: Uses, Safety and Approval Status

What is Rejuran, and what is a polynucleotide (PN)?

Rejuran is a brand of injectable that contains PN (polynucleotide) as its active material, made by PharmaResearch of South Korea [3][5]. The maker describes Rejuran as a medical device [5].

A polynucleotide is a long-chain polymer built from DNA units [1]. For current products the raw material comes mainly from the reproductive cells of salmon and trout [1][3]. So it is not collagen and not hyaluronic acid.

The authors of a 2026 expert-opinion paper propose that PN may form a water-holding, net-like scaffold in the dermis and may activate fibroblasts, the cells that make collagen [3]. The same authors say the exact mechanism is still under investigation [3]. So do not assume PN works like other collagen stimulators just because of how it is marketed. See the whole group in [[collagen-stimulator-types-explained]].

What is the difference between PN, PDRN and Rejuran?

PDRN and PN are similar DNA-derived polymers and the two words are used interchangeably in studies, while Rejuran is one maker's brand name [1][3]. A 2025 review says this swapping of terms has caused confusion among clinicians and scientists [1].

The authors of that review propose a cut-off: DNA chains of short to medium length (molecular weight below 1500 kilodaltons) would be called PDRN, and longer chains PN [1]. This is the authors' proposal, and other papers cited here still use the two words interchangeably [1][2].

The first drug containing PDRN was Placentex, approved in Italy in 1994 and made by Mastelli, as an injection for certain connective-tissue disorders; its PDRN was first extracted from human placenta [1]. That is a different product from Rejuran, and it was not an approval for cosmetic use.

What does Rejuran do, according to the studies?

A systematic review found that PN injections improved wrinkles, skin texture and elasticity with statistical significance in several studies, but rated the evidence low to moderate quality [2]. Its authors conclude that there is no consensus on how best to use PN and that higher-quality studies are needed [2].

The review covers 9 studies with 219 participants in total, published from 2014 to 2022 [2]. Seven were done in Korea and two in Italy [2]. None scored full marks for quality, and differences in how outcomes were measured meant the results could not be pooled [2].

Crow's feet were the most studied area (4 studies); others covered the scalp, acne scars, nasolabial folds, post-inflammatory dark marks and the cheeks [2]. One example is a randomised, double-blind, split-face trial comparing Rejuran with hyaluronic acid around the eyes of 27 Korean women, followed for 28 weeks. Pore volume improved more on the PN side than on the HA side at weeks 16 and 28 [2].

The longest follow-up among the included studies was 28 weeks [2]. In one study the skin-texture improvement seen at 3 months was somewhat smaller at 6 months but still better than before treatment [2]. So there is no standard figure for how long results last.

An international expert panel, including a dermatologist from Thailand, proposes four uses for PN: hydration and rejuvenation, deeper structural support, care of rosacea and eczema, and scars [3]. This is expert opinion, not a regulator-approved indication. Some authors are advisers to or employees of the maker, and the writing was funded by the maker. The authors themselves say the evidence is still limited [3].

A second 2024 review gives a similar picture: some studies found significant gains in elasticity and hydration, others reported limited or no benefit, and it asks for more research [4].

Who is Rejuran for, and who should be careful?

The studies mostly enrolled Korean and Italian adults, so they cannot say who benefits most, and no list of contraindications taken from a Rejuran leaflet was found in the sources read [2]. Average ages ranged from 33.9 to 55.71 years, most participants were women, and no included study was done in Thailand [2].

The expert panel calls PN a promising option for sensitive skin or skin with a damaged barrier [3]. That is the opinion of experts with ties to the maker, and it is low-level evidence [3].

Because PN is made from salmon or trout DNA [1][3], ask the doctor whether a seafood or drug allergy history matters, and ask to see the leaflet of the exact product the clinic will use. The doctor judges your skin and health history case by case.

What are the side effects and risks of Rejuran?

No severe side effects were reported in the included studies; what was reported were local effects such as swelling, pain, itching, redness and bruising, and long-term safety data are limited [2][3]. The 2024 review summarises side effects overall as mild and transient [2].

The numbers differ a lot between studies. One randomised study reported treatment-emergent local adverse events in 31.9% of participants. Other studies found swelling at the injection site in 50.00% and 71.42%, while two studies found no side effects at all [2].

The expert panel says no cases of granuloma (a hard lump) or vascular occlusion have been linked to PN in the literature, but rare events cannot be excluded, and long-term data from registries or post-market surveillance remain limited [3]. Each included study had only 5 to 72 participants [2], too few to show very rare risks.

A second review reminds doctors to be aware of the limits and possible risks of PN [4]. Injections should be done by a licensed doctor only.

Is Rejuran approved or registered?

What can be checked is that the maker says Rejuran is a medical device and a news report says Korea approved one version; Thai FDA (อย.) and US FDA status must be checked by registration number [5][6][7].

South Korea: Korea Biomedical Review reported on 3 August 2021, citing a PharmaResearch statement, that Rejuran HB Plus, a PN-based medical device, had won approval from Korea's Ministry of Food and Drug Safety [6]. The report covers one version, not every product in the Rejuran line.

Europe: in a press release on 28 August 2025, the maker's CEO said Rejuran is the only PN-based medical device approved under the EU Medical Device Regulation (EU MDR) [5]. That is the maker's own statement, and this article could not check it against a European database.

United States: no US FDA document approving Rejuran was found in the sources read, so this article does not treat it as approved. The FDA's own databases could not be searched directly while writing. Compare Sculptra, which has a clear FDA approval page: [[sculptra-plla-explained]].

Thailand: no Thai FDA (อย.) page giving a Rejuran registration number could be opened, so Thai status is not confirmed here. The Thai FDA's Medical Device Control Division runs a site for checking products [7]. Ask to see the registration number on the box or documents of the product the clinic uses, and check it with อย. before deciding.

What should I ask a doctor before having Rejuran?

Ask which product and registration number will be used, what evidence supports the area you want treated, what the risks are, and who handles problems afterwards [2][3][7]. This is a procedure for a licensed doctor, not something to buy and inject yourself.

To see how skin boosters differ from fillers, read [[skin-booster-vs-filler]]. Related substances are covered in [[exosome-skin-explained]] and [[profhilo-explained]].

Questions to take with you [2][3][7]:

• Which Rejuran product is it, and does the registration number on the box match what the Thai FDA site shows? [7]
• What evidence supports treating the area I want, and who took part in those studies? [2]
• Which allergies, seafood allergy history and skin conditions should I tell you about? [3]
• Which side effects can happen, and what is still unknown, such as long-term safety? [2][3]
• If something looks wrong afterwards, who looks after me and how do I reach them?
• Are you a licensed doctor trained on this product?