Rejuran Korea Side Effects: Which Are Normal and Which Aren't
Dr. Jong Seon Kim · Director, Gangnam HERA7 min readLast updated 
On this page
Worried that Rejuran Korea side effects, like raised bumps or under-eye bruising, will still be on your face when you board your flight home?
Read this before you book the injection day.
By the end you'll know which reactions are normal and how long they usually last, what reviews get right and wrong, which Rejuran method fits your skin, and what decides the cost. That's enough to choose a version, and a day, that suits your face and your trip.
Hello, I'm Dr. Jong Seon Kim, Director, Gangnam HERA Plastic Surgery Clinic, and a Board Member of the International Petit Medical Society.
At HERA, the specialist who consults with you is the one who performs your treatment. The sealed vial is opened in front of you, and Korean and international patients pay the same price, with a written estimate before treatment.
I wrote this because most people who worry after Rejuran are worrying about the bumps, which are expected, while the few signs that do need a doctor get far less attention.
The usual side effects are small raised bumps at each injection point, redness, tenderness and sometimes bruising. On the cheeks the bumps typically flatten within a day or two; bruises can take around a week, and thin under-eye skin tends to show everything for longer.
If your dates are fixed, send your flight-home date on WhatsApp with the one question on your mind: how many days before that flight should the injection be?
Book a consultation
Send us your question or a photo on WhatsApp and we will reply in English.
Which Rejuran method suits your skin?
Rejuran is a polynucleotide injection: purified DNA fragments from salmon, placed in the skin as many tiny deposits. Research reviews describe polynucleotides as supporting the skin's repair environment and the activity of fibroblasts, the cells that make collagen (Pharmaceutics review, via PubMed Central). Those tiny deposits are also the reason for the bumps. Each one is product sitting in the skin until it disperses.
At HERA there are three versions: Rejuran, Rejuran HB and Rejuran I. Rejuran I is the version designed for the eye area, where the skin is thinnest. Which one fits depends on the area and your goal, and I go through the differences in our polynucleotide skin booster guide.
Rejuran tends to suit you if your skin is thin, crepey or tired-looking and you want its texture and quality to improve gradually. It's a poor fit if what bothers you is lost volume or deep folds, because it doesn't fill. If you want collagen stimulation from a different material, Juvelook is the option people often weigh against it, and its reactions behave differently, as I explain in what's normal after Juvelook.
Which Rejuran side effects are normal, and which are not?
Most reactions come from the needle and the deposits themselves. A systematic review of polynucleotides in aesthetic medicine found that reported adverse effects were generally mild and short-lived, mostly at the injection site (Journal of Cosmetic Dermatology, via PubMed Central).
Risks and side effects to know
Common and temporary. Bumps at each injection point, usually flattening within one to two days on the face. Redness and mild swelling for about a day. Tenderness when you touch the area. Pinpoint marks and bruises, which can take around a week to fade, longer if you bruise easily.
Who should wait or skip it. As general medicine, I'd hold off if you have an active infection, cold sore or acne flare where the injections would go, if you've had a laser treatment or chemical peel on the same area very recently, or if you're taking isotretinoin. Pregnancy and breastfeeding are reasons to wait. Because the active ingredient comes from salmon, a fish allergy or a known allergy to any ingredient must be raised before anything is injected. Blood thinners and some supplements make bruising more likely, so bring the list.
What is not normal. Pain that gets worse after day two, redness that spreads, warmth, pus or fever can point to infection. Firm lumps still there after a couple of weeks deserve a look. Any change in vision after an injection near the eyes is an emergency, wherever you are.
If it happens after you fly home. See a doctor where you live promptly. Before you leave Seoul, keep a note of the product name, the areas treated and the date. The CDC's medical tourism advice is to bring copies of your treatment records home with you (U.S. Centers for Disease Control and Prevention).
Rejuran eye side effects: why the under-eye area behaves differently
Rejuran eye side effects are the same reactions you get elsewhere, just easier to see. Under-eye skin is thin, so a bump that vanishes overnight on the cheek can stay visible for a few days, and bruises show more. Swelling is often worse in the morning, because fluid collects there while you lie flat.
Say you have thin under-eye skin, you bruise easily, and you fly home on a Sunday. I'd want the eye treatment early in your stay. HERA is closed on Sundays, so a Saturday injection means boarding with the freshest bruises and no chance to come back in before you leave. If your skin is also flaring that week, I'd treat the cheeks on this trip and leave the eyes for the next one.
If the under-eye area is your main concern, send a close-up photo of your eyes in daylight with a neutral face, plus a list of any blood thinners or supplements you take, and ask which version would be used there.
Book a consultation
Send us your question or a photo on WhatsApp and we will reply in English.
What Rejuran reviews get right and wrong
Review threads tend to repeat three claims. “The bumps look like mosquito bites” is accurate, and expected: they're the product in the skin, not an allergy. “It's one of the more painful boosters” is partly true. Many shallow injections sting, and how much you feel varies with the area, the numbing and your own tolerance. Topical numbing cream is commonly used.
“One session changed everything” is the claim I'd treat with care. Studies of polynucleotides generally follow a course of treatments, with changes in texture and elasticity building over weeks (real-life assessment, Journal of Cosmetic Dermatology). A glow the next morning is often hydration and mild swelling.
What decides the cost of Rejuran in Korea?
I don't put figures on this page, but these are the things that move the number:
- the version: Rejuran, Rejuran HB or Rejuran I
- the area: full face, under-eye only, or both
- how many sessions you plan, and whether they fit one trip
- whether you combine it with another treatment on the same visit
Korean and international patients pay the same price at HERA, with no surcharge for foreigners, and you get a written estimate before treatment, so you see the figure before anything is injected. You can browse the treatment menu and doctors on the HERA English site, then ask on WhatsApp what it would cost for your case, with a photo of the area.
If you're combining treatments, side effects add up. A lifting device brings its own reactions, which I cover in Ultherapy side effects and what can go wrong with Thermage. A wrinkle-relaxing injection on the same trip has its own list in muscle-relaxing injections side effects.
Genuine product, opened in front of you
Two things matter for trust here. Only genuine, approved products are used, and the sealed vial is opened in front of you, so you know what's going into your face. And the specialist who consults with you is the one who performs your treatment, never handed off to someone else.
We don't rush through high volumes. Every treatment begins with a 1:1 consultation, and that's where we agree on only what you need.
How should you plan recovery around your flight?
The timeline below is general and typical. Easy bruisers and the under-eye area sit at the slower end.
| When | Face | Under-eye |
|---|---|---|
| Same day | Bumps, redness and pinpoint marks | Bumps, puffiness, bruising may appear |
| Day 3 | Bumps usually gone; any bruise turning yellow | Bumps flattening; morning swelling easing |
| Day 7 | Most people look as usual | Most bruising fading |
For the first day or two, many doctors suggest skipping alcohol, saunas and hard workouts, and not rubbing or massaging the treated skin.
Avoid the day before your flight.
Fresh bumps, possible bruising and a long seat in dry cabin air make a poor combination, and you lose the chance to be seen again if something looks off. Leave a few days between injection and departure, more for the eyes.
The treatment itself. If you want the clinical detail — who it suits, how a session runs, recovery and the honest limits — it is set out on our Rejuran page.
Visiting HERA in Gangnam
HERA is at 4F, 9 Seocho-daero 73-gil, Seocho-gu, Seoul, three minutes from Gangnam Station. Take the external elevator on the side of the building up to the 4th floor. Hours are Monday and Friday 10:00–20:00, Tuesday to Thursday 10:00–19:00 and Saturday 10:00–17:00, with lunch from 13:00 to 14:00; the clinic is closed on Sundays and public holidays. HERA is registered with Korea's Ministry of Health and Welfare to treat international patients, and consultations can be held with an English interpreter.
One photo is enough to start. Send a daylight photo of the area that bothers you on WhatsApp and ask which Rejuran version fits it, and on which day of your trip. When you come in, I'll examine your skin in person and recommend only what fits it.
FAQ
Frequently asked questions
Q1Can I fly the day after Rejuran?
Flying itself is usually not the problem. The issue is boarding with fresh bumps or bruises and no chance to be seen again if something looks wrong. Leave a few days between the injection and your flight, and more if you're having the under-eye area treated.Q2Can I wear makeup after Rejuran?
Many doctors suggest keeping makeup off the treated skin for the first day, while the tiny injection points close. Ask at your consultation what applies to the areas you're having treated.Q3I'm allergic to fish. Can I still have Rejuran?
Rejuran's active ingredient comes from purified salmon DNA, so a fish allergy has to be raised before anything is injected. The doctor examining you weighs your allergy history before deciding whether it's suitable.Q4Are the bumps a sign the injection was done badly?
No. The small bumps are the product sitting in the skin and are expected after Rejuran. Lumps that are firm, uneven or still there after a couple of weeks are different and deserve a check by a doctor.Q5How many Rejuran sessions do people usually need?
Studies of polynucleotides usually follow a course of several sessions spaced weeks apart, because changes in skin quality build gradually. The number that makes sense for you is agreed at your consultation, based on your skin and your travel plans.
Real stories
What Our Patients Say
Videos posted by patients who came from abroad.
Is morning the best time for upper eyelid fillers? 🤔 Our doctor explains why the timing of your appointment can make a difference during your consultation. Watch until the end to learn why. ✨
@gnheraclinic_en
Can one thread lift improve both lifting and skin quality? 🤔 Our doctor explains how the key components of the Aptos Thread Lift work and what makes it different from traditional threads. Watch until the end to learn more. ✨
@gnheraclinic_en
Thinking about a thread lift? 🤔 Aptos is more than just a PDO thread. Our doctor explains what makes it different and why it's become a popular lifting option. Watch until the end to learn how it works. ✨
@gnheraclinic_en
Would you choose sedation for Ultherapy? 🤔 Our doctor shares why he personally wouldn't recommend it—even for his own family. Watch the full explanation before making your decision. ✨
@gnheraclinic_en
HIFU or RF — which one does your face actually need? They both lift your skin — but in completely different ways. Which one is right for your face? Explained by a Korean aesthetic doctor. Save this before getting a lifting treatment.
@gnheraclinic_en
Noticing drooping mouth corners after 40? A small change can make a big difference. Lip filler + corner Botox ✔ Restore lip volume ✔ Lift the mouth corners ✔ Brighter smile 📍Gangnam HERA Clinic – Seoul Korea Follow @gnheraclinic_en
@gnheraclinic_en
Re2O vs Rejuran Which skin booster is right for your skin? Korean aesthetic doctor explains the difference.
@gnheraclinic_en
HIFU = Hollow Cheeks? Depends on your face type. Slim faces + strong HIFU can cause volume loss. Customized treatment is key.
@gnheraclinic_en
Jaw Botox mistake? Here’s why some faces look “peanut-shaped.” Placement matters. Save this before your next appointment.
@gnheraclinic_en
Want a smaller-looking face? It’s about placement. Save this.
@gnheraclinic_en
One treatment I’d recommend for parents? You might be surprised.
@gnheraclinic_en
✨ Under-Eye Filler Correction & Re-Treatment ✨ Sometimes, filler isn’t about adding more — it’s about doing it properly and safely. In this case, the under-eye area required: ✔ Filler dissolving (hyaluronidase) ✔ Careful assessment of the depth and placement ✔ A natural re-treatment for a smoother result The tear trough is one of the most delicate areas of the face, so precision and experience truly matter. At Gangnam HERA Clinic in Seoul, we specialize in: 💎 Under-eye filler correction 💎 Tear trough rejuvenation 💎 Natural, balanced results (never overfilled) If you’re visiting Korea and looking for a trusted clinic in Gangnam, Seoul, we provide full English support for international patients. 📍Gangnam, Seoul 📩 DM us to book a consultation
@gnheraclinic_en
✨ Chin Filler for Facial Balance ✨ A small change can make a big difference — especially in your side profile. At Gangnam HERA Clinic in Seoul, chin filler is designed to: ✔ Improve facial harmony ✔ Enhance the jawline naturally ✔ Create a softer V-line effect ✔ Support a more defined profile (without surgery) Our treatments are doctor-performed, highly precise, and always tailored to your unique facial structure. If you’re looking for natural chin filler in Gangnam, Seoul, we offer full English support for international patients. 📍Gangnam, Seoul 📩 DM us for consultation & booking
@gnheraclinic_en
✨ Natural Lip Filler in Seoul (Gangnam) ✨ Subtle, balanced, and beautifully tailored to your facial features. At Gangnam HERA Clinic, our lip filler treatments focus on: 💗 Soft volume (not overdone) 💗 Better lip symmetry 💗 A more youthful, refreshed look 💗 Doctor-performed, precision-based results If you’re visiting Korea and looking for a trusted clinic in Gangnam, Seoul, we provide full English support for international patients. 📍Located in Gangnam, Seoul 📩 DM us to book your consultation
@gnheraclinic_en
Restore Your Youth: The Magic of Hand Fillers ✨✋ Do you find yourself hiding your hands because of visible veins, tendons, or wrinkled skin? As we age, we lose volume in our hands, making them look older than we feel. But you don't have to let your hands give away your age! At Gangnam HERA, we provide a professional solution to restore that smooth, youthful look: ✅ Volume Restoration: Fills in hollow areas where fat has been lost. ✅ Vein & Tendon Camouflage : Softens the appearance of protruding vessels for a softer look. ✅ Smooth Texture : Deeply plumps the skin to reduce the "wrinkled" appearance. Experience an instant rejuvenation with natural-looking results. Let your hands match your youthful glow! 💎
@gnheraclinic_en
The Secret to "Soft Tofu" Skin? Only at Gangnam HERA! 🥛✨ Ever heard of the "Soft Tofu" Skin Booster? Just like the name suggests, it’s the ultimate secret to achieving a bouncy, bright, and milky-white complexion. The star ingredient is Glyju, a revolutionary booster made from Glyceollin (soybean-derived) ✅ Powerful Whitening: Blocks melanin synthesis for a clearer skin tone. ✅ Vascular Health: Promotes skin regeneration and healthy glow. ✅ Instant Hydration: Packed with Hyaluronic Acid to erase dryness. Why Gangnam HERA? 🤫 Glyju is amazing on its own, but we do it differently. At HERA, we combine it with an exclusive secondary treatment that boosts the results by 200%. This unique "Secret Formula" is available only at our clinic, giving you that signature whitening glow you can't find anywhere else. Ready for your Soft Tofu transformation? Experience the newest trend in Gangnam! 💎
@gnheraclinic_en
Juvelook I + EBD The Perfect Synergy 💉⚡️ Why combine Juvelook I with Energy-Based Devices (EBD)? Because they work better together! Juvelook I: Stimulates deep collagen production. EBD : Tightens skin tissue using thermal energy. At Gangnam HERA, we provide both to give you volume and lifting at the same time. 🕒 Already had Juvelook? We recommend a 2–3 week interval for absorption before starting your device treatment.
@gnheraclinic_en
I asked AI (Gemini 3.0) about the future of lips, and the answer was clear: Be Yourself. ✨ 🎬 2026 Lip Trends (Quick Summary) 1️⃣ Beyond Volume 👄 Less is More! It’s all about a natural, healthy glow over fake volume. 2️⃣ Hybrid Care 💧 Filler + Skin Booster (Rejuran/Exosome). Shape with filler, hydrate with boosters. 3️⃣ Advanced Safety 🛡️ New materials, longer results, and fewer side effects. (P.S. I asked Gemini how old it is, and it said it doesn’t age... Must be nice! But for us humans, we have Gangnam HERA to keep us youthful! 😂) 📍 Visit us in Gangnam for your 2026 personalized lip design.
@gnheraclinic_en
Stop guessing! Here is the REAL difference between Rejuran i and Juvelook i. 👇 ✅ Rejuran i Hydration & Glow. Perfect for fixing dry, "crepey" skin and adding that healthy inner radiance. ✅ Juvelook i Natural Volume. Perfect for filling hollow tear troughs by boosting your natural collagen. No bumps, just smooth skin. One heals the skin, the other fills the hollows. Which one is your concern? Tell us in the comments! 💬
@gnheraclinic_en
Say goodbye to vertical neck wrinkles—WITHOUT surgery! 🙅♀️✨ Vertical neck lines used to be the hardest to treat, often needing a surgical neck lift. But the trend has changed. Now introducing the CaHA Skin Booster treatment! 💉 By spreading diluted calcium filler evenly under the vertical folds, we stimulate your skin to regain its firmness and bounce naturally. Perfect for ✅ Loss of skin elasticity ✅ Deep vertical neck bands ✅ Those wanting surgical results without the downtime The future of neck rejuvenation is here at Gangnam HERA. 🤍
@gnheraclinic_en
Even without lifting, your look can change this much. By adding only the necessary amount of filler to the temples, lateral cheeks, and chin, and combining chin Botox with Juvelook Eye, we refined the overall balance. Not to look unnaturally younger, but natural and smooth. This is a case that shows how much of a difference filler alone can make. 📩 For consultations and appointments, please contact us via DM or WhatsApp. * Results may vary by individual.
@gnheraclinic_en
As we enter our 40s, many people start to notice: ✔️ Looser facial contours ✔️ A double chin ✔️ Deeper neck lines Improvement isn’t only about “lifting.” By reducing excess volume, refining the contours, and adding volume only where needed, the overall appearance can change significantly. This case combines: Ultherapy, fat-dissolving injections, Botox, and filler. Not to look unnaturally younger, but to look natural, clean, and refined. We offer facial contouring tailored for your 40s, with a balanced and thoughtful approach. For inquiries and appointments, please contact us via DM or WhatsApp.
@gnheraclinic_en
A special New Year message from the doctors at HERA. 💌 May your 2026 be as bright and glowing as the skin you’ve always dreamed of. We are so grateful to be part of your beauty journey. Stop the screen to reveal the blessing waiting for you! 🧧✨ Wishing you a year of overflowing happiness and health. Happy New Year! 🎊
@gnheraclinic_en
Body Ultherapy? 👀 Meet Sizer. 📢FDA-approved for belly fat reduction. Goes deeper. Works better. Sizer + fat-dissolving injections = 🔥
@gnheraclinic_en
On YouTube
Hear it from the doctors before you fly
Our doctors explain HERA's main treatments, lifting, filler and skin boosters, on camera, so you know who you are meeting and how they think before you land in Seoul.
Korean audio · auto-translated captions available on YouTube
16 videos
- 6:24Filler
Dr. Kim and Dr. Lee sort out how fillers, collagen injections and skin boosters differ, and which concern each one is for.
Dr. Jong · Dr. Jong - 7:36Clinic & doctors
HERA podcast ep. 3 — Dr. Kim and Dr. Lee look at the same face and explain the treatments they would choose, and why.
Dr. Jong · Dr. Jong - 8:07Lifting
What APTOS threads are, who they are recommended for, and a real patient's treatment and before-and-after.
Dr. Jong - 5:44Lifting
How APTOS compares with other lifting threads, what recovery is like and how long results last.
Dr. Jong · Dr. Jong - 4:20Filler
Dr. Kim shows how injection technique changes with the amount of filler, and how filler dissolves.
Dr. Jong - 5:50Filler
What a hollow upper eyelid is, filler vs fat grafting, how long it lasts and what to watch for.
Dr. Jong - 5:20Filler
Dr. Kim breaks down lip proportion, volume and mouth corners using well-known Korean celebrities' lips as examples.
Dr. Jong - 5:39Skin & boosters
Hydration, pores, breakouts or tone — matching the skin booster to what your skin actually needs.
Dr. Jong - 6:05Skin & boosters
Dr. Lee explains how Lituo and CaHA work, how they are injected and how often.
Dr. Jong - 5:00Skin & boosters
What Juvelook Eye is, what it is used for, how many sessions it takes and how long it lasts.
Dr. Jong - 5:56Lifting
Why lines form around the eyes, which treatments are combined, and Eye Thermage vs Eye Ulthera.
Dr. Jong - 4:58Lifting
Why Dr. Lee cares about lifting, and what he looks at first when he sees a patient.
Dr. Jong - 3:30Clinic & doctors
Dr. Han talks about what matters most in a consultation and the approach behind every treatment.
Dr. Jin - 5:29Skin & boosters
A tour of HERA's main devices and which skin concern — pores, texture or firmness — each one helps with.
Dr. Jong - 4:40Clinic & doctors
Three areas brides care about, recommended treatments, and what still works with a month to go.
Dr. Jong · Dr. Jong - 4:39Clinic & doctors
What an AI skin scan measures — wrinkles, pigment, firmness, pores — and why a doctor's consultation still matters.
Dr. Jong · Dr. Jong
Shorts
One question, under a minute
HERA TV
The doctors explain it on camera — then in writing
Each piece is written by the doctor from their own YouTube video: the patient question, why it happens and how we approach it.
6:24korean plla fillerKorean PLLA Filler? Filler vs Collagen Booster vs Skin Booster
Is PLLA a filler? Two Gangnam HERA doctors sort out the three injectable families that confuse most patients — filler, collagen boosters and skin boosters — and how to combine them by area.
Dr. Jong Seon Kim7 min read
4:21neck line fillerNeck Line Filler: One Treatment, Start to Follow-Up
A Gangnam plastic surgeon treats a young patient's two neck lines on camera — why the lines form, why they are filled slightly high at first, how much it hurts, and what the follow-up visit showed.
Dr. Jin Yi Han6 min read
5:39korean skin boosterKorean Skin Booster: How to Choose by Your Skin's Main Problem
There are so many Korean skin boosters that patients freeze. A Gangnam doctor sorts them by the four problems that matter — hydration, pores, inflammation and brightness — and names the one he would pick if he could only choose one.
Dr. Jong Seon Kim7 min read
HERA Journal
Keep reading
Skin boostersHow Long Does Rejuran Take? Chair Time, Bumps and Trip Days
A Rejuran visit usually takes half a day at most, and the small injection bumps typically flatten within one to three days. The full course takes longer: sessions are spaced two to four weeks apart.
8 minRead →
Skin boostersWhen Does Rejuran Start to Show? Bumps, Weeks and Your Flight
Rejuran's injection bumps usually settle in a day or two and hydration often shows within weeks, while texture changes build over a course. Dr. Jong Seon Kim on which day of your Seoul stay to book it.
8 minRead →
Skin boostersHow Long Does Rejuran Last? Months, Sessions and Trip Days
After a course of about three sessions spaced weeks apart, Rejuran's effect commonly holds for six months to a year. The bumps settle in one to three days, so session spacing shapes your trip more than downtime.
8 minRead →
Visit us
Find Gangnam HERA
In Seocho-gu, Seoul, a three-minute walk from Gangnam Station Exit 9. Tap the map for directions.
Address
4F, 9 Seocho-daero 73-gil, Seocho-gu, Seoul, Republic of Korea
Opening Hours
Tuesday, Wednesday, and Thursday: 10:00 AM – 7:00 PM; Monday, Friday: 10:00 AM – 8:00 PM; Saturday: 10:00 AM – 5:00 PM; Lunch break: 1:00 PM – 2:00 PM; Closed on Sundays and public holidays
