Skin boosters
Rejuran salmon DNA side effects: OK with a fish allergy? Cost, reviews, methods
The salmon DNA in Rejuran is purified, but a fish allergy, a skin infection or pregnancy are still reasons to ask before an injection. The clinic answers WhatsApp messages within 24 business hours.
Written and medically reviewed by Dr. Jang Dong-hoon · Founder & Medical Director
Published · 10 min read
Do you have a seafood allergy and wonder about Rejuran salmon DNA side effects before booking a treatment in Seoul?
Read this first, before your flight and injection date are fixed.
By the end you will know what “salmon DNA” means inside this injection, which side effects are normal and how long they last, who should wait, what decides the cost, and which review claims hold up. With that, you can decide whether Rejuran fits your skin and your health history, or whether another method makes more sense.
Hello, I'm Dr. Jang Dong-hoon, Founder & Medical Director of THE Beautiful Clinic in Seoul.
At our clinic I consult, plan and treat myself. The consultation begins with a 3D scan of your skin, before any price list is opened. You can ask on WhatsApp in English or Bahasa Indonesia, and the clinic answers within 24 business hours.
I wrote this because many people picture “salmon DNA” as fish meat being injected into the face. In reality, the reasons doctors more often find to postpone are ordinary ones: inflamed acne, a medication you are taking, or a laser you had last week.
The most common Rejuran salmon DNA side effects are pain during the injection, redness, swelling, small bumps at the injection points and bruising, which settle within a few days for many people. Allergic reactions are rarely reported, but a history of fish or salmon allergy is a reason to talk to the doctor before the injection.
If you are unsure, write your allergy list on WhatsApp: foods, medications and the reactions you have had. Then ask one thing: does Rejuran make sense with a history like mine?
What is the “salmon DNA” in Rejuran, exactly?
Rejuran contains polynucleotides (PN), chains of DNA taken from the reproductive cells of salmon or trout and then purified. A scientific review comparing PN and PDRN explains that both come from similar sources, differ in chain length and processing, and are used to support repair of skin tissue.
For the allergy question, this is the part that matters. A fish allergy is generally triggered by fish proteins, mainly parvalbumin, and DNA itself is not the usual trigger. Purification is designed to remove those proteins. So the risk is small, but I can't call it zero, because a very sensitive person can react to an extremely small residue.
One more thing that often gets mixed up. An allergy to shrimp, crab or clams is a shellfish allergy, driven by a different protein called tropomyosin. Many people react to shrimp yet eat fish without trouble, and the reverse also happens. So “seafood allergy” needs to be specific: which seafood, and what kind of reaction.
So when people ask about Rejuran salmon DNA side effects, most of the answer is about the needle and the fluid entering the skin, and only a small part is about the fish.
Common side effects and how long they usually last
One Rejuran session means many small punctures in the upper layer of the skin. A systematic review of polynucleotides in aesthetic medicine reports side effects that are generally mild and temporary, mainly pain, redness and swelling at the injection points. The table below sums up what you are likely to see in the mirror.
| Reaction | Usually | What you can do |
|---|---|---|
| Pain during the injection | During the procedure, then fades quickly | Tell the doctor if you are sensitive to pain and ask about the low-pain type |
| Small bumps at injection points | Settle within one to two days for many people | Don't massage or press them |
| Redness and swelling | A few hours to about two days | Short cold compress, skip the sauna |
| Bruising at one or two points | Can last about a week | Plan important events or photos after it |
| Itching, hives, spreading swelling | Rare | Contact a doctor right away; trouble breathing is an emergency |
Infection is also rare, but redness that keeps spreading, feels hot, produces pus or comes with fever in the days after the injection needs a doctor's exam. A firm bump that does not shrink after one to two weeks should also be seen in person.
If the bumps are your main worry, Rejuran side effects in Korea covers how long the bumps last and what happens around the eyes.
When should you postpone Rejuran?
This section matters most if you have allergies or take regular medication. In general, a doctor will suggest postponing or choosing a different material if:
- You have reacted to a PN or PDRN injection before, or have a confirmed fish allergy.
- There is inflamed acne, infection, an open wound or active cold sores in the area to be treated.
- You recently had a laser, a peel or filler in the same area.
- You are taking isotretinoin or a medication that affects healing; blood thinners also raise the chance of bruising.
- You are pregnant or breastfeeding, because safety data in these groups are limited.
Say you are 50, live in Surabaya, and once broke out in itchy hives after eating shrimp, but you eat salmon without problems. That history points more toward a shellfish allergy than a fish allergy. I would ask when the last reaction happened, how severe it was and which medications you take now before deciding anything.
It is a different story if you have had lip swelling or trouble breathing after eating fish. With that history I would not inject PN, and we would talk about a booster made from another material.
If your history matches anything on the list above, send on WhatsApp the names of the medications you take and, if you have one, a photo of your allergy test result. Ask which booster material makes more sense for that history.
Rejuran reviews: which claims hold up?
On TikTok and forums, a few claims about Rejuran come up again and again. Here they are, sorted by the medical facts.
“The bumps are gone overnight.” Partly true. Many small bumps do settle within one to two days, but a bruise at one or two points can last longer, so don't book an important event for the next day.
“If you're allergic to seafood, you can never have Rejuran.” Too simple. What matters is whether it is a fish or a shellfish allergy, and how severe the past reaction was.
“You see the result the next day.” Not quite. Skin can look fresher once the swelling goes down, but the improvement in skin quality from PN builds slowly and is usually developed over a course of sessions.
“Rejuran hurts a lot.” Pain varies with the area and each person's threshold. Does a Rejuran injection hurt? walks through it from the first needle to the flight home.
Methods: Rejuran types and options without fish DNA
Our clinic offers several forms of Rejuran: Rejuran for the face, Rejuran i for the eye area, Rejuran HB as the low-pain type, and Rejuran delivered with Dermashine. There is also the salmon injection (PDRN), which uses shorter DNA chains. The difference between the two is in PDRN for dry skin: serum or injection.
All of these options still come from fish DNA. If your allergy history makes PN a poor choice, there are boosters made from other materials, such as Juvelook, which is PLA based. Each material works on a different timeline, so the choice of material matters more than the brand. You can see the boosters we have on the Rejuran and skin booster treatment page.
If you are also considering lifting on the same trip, the side effects are different again. Read Thermage side effects before combining the two, and tell the doctor if you have had filler or threads in the last six months.
What decides the cost of your Rejuran?
I don't write figures here, because your cost depends on things that only become clear after the skin is examined. The main ones are the amount of product in cc, the Rejuran type (face, i or HB), the size of the area, whether Dermashine is used, and how many sessions are in the course.
If another material turns out to suit your allergy history better, the calculation changes with it. Ask on WhatsApp what it would cost for your case, with a photo of the area you want treated. You can also tick Rejuran in the booking selector and send the list on WhatsApp.
Your days in Seoul and after you fly home
The clinic is on the 2nd floor of the Jinryeong Building, a two-minute walk from Exit 5 of Nonhyeon Station (Sinbundang Line). There is no patient parking, so come by subway or taxi. Hours are Monday to Thursday 10:30 to 19:30, Friday 10:30 to 20:30 and Saturday 10:30 to 16:30 without a lunch break. Weekdays have a lunch break from 13:00 to 14:00, and the clinic is closed on Sundays and public holidays. The full address and contact options are on the THE Beautiful Clinic home page.
Boosters can often be done right after the consultation. If you have an allergy history, my advice is not to schedule the injection on your last day before the flight. Leave at least one day in Seoul so any redness or bumps can be watched.
Once home, small bumps and mild bruising usually need no treatment. Avoid saunas, hard exercise and long exposure to the tropical sun in the first days, and wear sunscreen. The CDC advises medical travelers to carry copies of their treatment records and to arrange follow-up care with a doctor at home, so ask for a note of the product name and the treated areas before you leave.
See a doctor in Indonesia if you notice spreading redness, heat, pus, fever, or a firm bump that keeps growing. Widespread hives, swelling of the lips or tongue, and trouble breathing are emergencies: go to the nearest emergency room right away. For minor concerns, send a photo of the area to the clinic on WhatsApp.
The first step is simple: send one daylight photo of your face, your allergy and medication list, and your dates in Seoul on WhatsApp, and ask whether Rejuran or another material makes more sense for you. You can ask before booking anything. When you come, I examine your skin with the 3D scan and recommend the treatment that fits your skin and your health history.
The short version
- Rejuran contains polynucleotides (PN), purified DNA from salmon or trout reproductive cells.
- Common side effects are pain, small bumps, redness and bruising, usually settling within a few days.
- A fish allergy and a shrimp or shellfish allergy are different things; tell your doctor about both.
- Inflamed acne or infection at the site, a recent laser, isotretinoin and pregnancy are reasons to wait.
- Cost depends on the number of cc, the Rejuran type, the area and the number of sessions.
Questions patients ask
Does Rejuran contain fish protein?
Rejuran contains DNA chains (polynucleotides) purified from salmon or trout reproductive cells. Purification is designed to remove the proteins that usually trigger fish allergy, so the risk is small. People with a severe fish allergy should still discuss it with the doctor before the injection.
I'm allergic to shrimp. Can I still have Rejuran?
A shrimp allergy is a shellfish allergy, triggered by a different protein from fish allergy. Many people allergic to shrimp are not allergic to fish. Describe the reaction you had and when it happened, and the doctor will weigh it with you at the consultation.
How long do the bumps last after Rejuran?
For many people, the small bumps at the injection points settle within one to two days. A bruise at one or two points can last about a week. A firm bump that does not shrink after one to two weeks should be examined by a doctor.
Can I have Rejuran while pregnant or breastfeeding?
Safety data on polynucleotides in pregnancy and breastfeeding are limited, so the general advice is to wait until that period is over.
Can Rejuran be done on the day of the consultation?
Boosters can often be done right after the consultation. If you have an allergy history, leave at least one day in Seoul after the injection so any skin reaction can be watched before you fly.
What should I do if a reaction appears after I fly home?
Mild redness and small bruises usually fade on their own. Spreading redness, heat, pus or fever need a local doctor's exam. Widespread hives, lip or tongue swelling, or trouble breathing are emergencies.
Results and recovery vary between individuals, and every treatment can have side effects. Prices are from the clinic's price list and are confirmed at consultation. This article is general information, not a diagnosis.
Sources
About the author
Dr. Jang Dong-hoon
Founder & Medical Director
Founder and medical director of THE Beautiful Clinic in Nonhyeon, Gangnam. He sees every patient's skin analysis before a plan is drawn, and reviews every article on this blog against what the clinic actually does.
Credentials in full
