Key takeaways
- Rejuran bumps usually flatten within 3 days. A lump that's still there after a week, or keeps growing, should be checked in person.
- Normal bumps: they appear right after the injections, feel soft, and get smaller every day.
- Possible nodule: it lasts past a week or shows up weeks later, and it may feel firm, look red, or hurt when pressed.
- Rejuran isn't FDA-approved in the US. In Korea, it's authorized by the MFDS as a medical device for temporarily improving facial wrinkles.
The small raised bumps you see after Rejuran usually flatten within about 3 days. If a lump is still there after a week, or it's getting bigger, redder, or sore, it's time to have it checked as a possible nodule. Those early bumps form because the injected gel draws in water at each injection point, and they spread out and settle as the days pass.
Why Do Rejuran Bumps Show Up, and How Long Do They Last?
Why Do Rejuran Bumps Show Up, and How Long Do They Last?
Those bumps are where the product went in. Rejuran Healer (sold in Korea simply as Rejuran) delivers polynucleotides, or PN, into the dermis in many tiny droplets. PN attracts water, so each droplet swells a little and lifts the skin above it. That's the bumpy, "embossed" look many people notice in the mirror that evening.
Polynucleotides (PN): purified DNA fragments taken from salmon or trout.
In an ultrasound study of 31 people who received 2 mL of Rejuran on the face, the product sat at an average depth of 0.55 mm. Ten minutes after injection, each droplet had already pulled in moisture, swelling into a small dome and spreading sideways. The same study measured how thick the dermis is across the face. It was 0.53 mm under the eyes and up to 1.18 mm at the temples and outer cheeks, which helps explain why bumps can look more obvious under the eyes.
Why Do Rejuran Bumps Show Up, and How Long Do They Last?
How long should you expect them? A panel of 101 East Asian practitioners who use a different PN product line agreed that bumps typically disappear within 72 hours. Redness and bruising at the injection points followed about the same timeline. Keep in mind that this is expert consensus on a related product, not a Rejuran trial, and everyone's skin is different.
Bump or Nodule? How to Tell by Timing and Touch
Bump or Nodule? How to Tell by Timing and Touch
A normal bump is there from the start and shrinks day by day. A nodule is a lump that stays the same size past a week, or one that appears weeks after your skin had already settled. Checking four things in the mirror can help you sort out which one you're looking at.
| What to check | Normal bump | Possible nodule or granuloma |
|---|---|---|
| When it appears | Right after the injections | Stays from day 1, or shows up weeks to months later |
| How it feels | Soft and small | Firm, or like a small bead that moves under the skin |
| Over time | Usually flat within 3 days | Same size after a week, or growing |
| What comes with it | Light redness, small bruise | Red or red-brown color, tenderness, oozing |
Granuloma: a firm lump that forms when immune cells wall off material the body can't break down.
One reason a lump lasts is that too much product went in too close to the surface. In a published case, a 40-year-old woman had hyaluronic acid skin booster injections for neck lines. The lumps appeared right away and were still there 6 months later, and the authors pointed to superficial placement and excess volume. That was a different ingredient from Rejuran, so it doesn't predict what will happen to you. Still, it's a good reason not to wait it out if your bumps aren't shrinking after a few days.
Can Rejuran Cause Lumps Months Later?
Can Rejuran Cause Lumps Months Later?
So far, published reports linking PN injections to granulomas or nodules are hard to find. That said, long-term follow-up data are still limited, so rare events can't be ruled out. A systematic review that pooled 9 studies and 219 people found no severe side effects. Milder reactions like pain, swelling, itching, and bruising typically cleared within a week.
Dermal fillers are a different story. Nodules and granulomas are listed as a less common risk, and side effects can appear weeks, months, or even years after the injection*.
Based on US FDA guidance on dermal fillers.
A granuloma usually shows up as a red or red-brown raised lump. When filler is involved, ultrasound can help show its depth and shape without a biopsy. If you feel a new lump months after Rejuran, don't assume it's from Rejuran. Have it examined so the actual cause can be found.
Skin Booster Side Effects: When to Contact Your Provider
Skin Booster Side Effects: When to Contact Your Provider
Bumps, light redness, and small bruises in the first 3 days are part of normal healing. Don't try to massage or squeeze them flat. Taking a photo each day in the same light makes it easier to see whether they're shrinking.
Skin Booster Side Effects: When to Contact Your Provider
Contact the clinic where you were treated and get checked if you notice any of these:
- A lump that hasn't shrunk after a week
- A lump that keeps growing, turns red, or hurts when you press it
- Pus, fluid draining from an injection point, or a wound that opens
- A new lump that appears weeks after your skin had settled
Seek medical care right away if the skin near the injection site turns white, gray, or blue, or if you have unusual pain. Go to the nearest emergency room if you notice vision changes or signs of a stroke: sudden difficulty speaking, numbness or weakness in your face, arms, or legs, difficulty walking, face drooping, severe headache, dizziness, or confusion*.
Based on US FDA guidance on dermal fillers. Rejuran isn't a filler, but it is injected, so these signs are worth knowing.
Planning Around a Trip to Seoul
Planning Around a Trip to Seoul
Flying isn't a reason to postpone Rejuran, unless you had sedation that day. Rejuran is usually planned as a series rather than a single visit, and the changes tend to build gradually. One session in Seoul doesn't replace the full course your provider recommends.
If you leave within the first 3 days, you may still have visible bumps on the plane, so plan your photos and meetings with that in mind. Once you're back home, you can send photos and questions to the clinic through WhatsApp. If you notice skin color changes, a growing painful lump, or any vision or speech problem, see a local doctor or go to a hospital first instead of waiting for a reply.
What to Ask Before Your Next Rejuran Session
How noticeable your bumps are depends partly on technique. Bumps tend to be more common when a needle places many tiny droplets, and bruising tends to be less common with a blunt cannula. Some practitioners also suggest using a lower-strength, PN-only product around the eyes to reduce bumps there.
Before your next session, ask, "For my under-eye area, will you use a needle or a cannula, and how deep will the product go?" That one answer makes it easier to compare with last time. If you can, show photos of how many days your bumps lasted, and point out any spot that stayed raised for more than a week. STON Clinic is in Myeongdong, inside Lotte Hotel Seoul near Euljiro 1-ga Station. When you message us, include your treatment date, the areas treated, and a clear photo of any lump.
If this raised a question about your own skin
Ask a questionReferences
- Ultrasound study of Rejuran injection depth and bumps in 31 people — Plast Reconstr Surg Glob Open, 2025 — PubMed Central
- Systematic review of 9 PN injection studies, results and side effects — J Cosmet Dermatol, 2025 — PubMed Central
- Expert consensus on bumps, redness, bruising, and aftercare with a related PN product — Clin Cosmet Investig Dermatol, 2025 — PubMed Central
- Expert perspectives on PN uses and reports of nodules or granulomas — Clin Cosmet Investig Dermatol, 2026 — PubMed Central
- Case of neck lumps lasting 6 months after a hyaluronic acid skin booster — J Cosmet Dermatol, 2025 — PubMed Central
- What a foreign body granuloma looks like and how it's diagnosed — DermNet NZ — DermNet NZ
- Dermal filler risks, nodules, and signs of a blocked blood vessel — US FDA — U.S. Food and Drug Administration
Frequently asked questions
Q. Is a Rejuran bump that lasts more than 3 days a nodule?
A. Not necessarily. A Rejuran bump that's still there on day 4 isn't automatically a nodule, because mild reactions typically clear within a week. From day 4, take photos in the same light to see whether it's shrinking. If it's unchanged after a week, or it turns firm or red, have it checked.
Q. When can I wear makeup after Rejuran?
A. Wait at least 6 hours, and ideally 12 hours, before applying makeup after Rejuran. That's based on an expert consensus for a different PN product, with extra caution after needle injections. When you do apply it, pat it on gently instead of rubbing over the bumps.
Q. How long should I avoid the sun after Rejuran?
A. Avoid direct sunlight and UV lamps for 48 hours after Rejuran. That window comes from an expert consensus for a related PN product. If you need to be outside during that time, a hat or umbrella that shades the treated area helps.
Q. Do under-eye Rejuran bumps last longer?
A. Under-eye Rejuran bumps can look more obvious, but they follow the same timeline. The dermis under the eyes is about 0.53 mm thick, among the thinnest on the face, so the same droplet shows more on the surface. If a lump there lasts past a week, have it checked.
Q. Will bruising from Rejuran fade along with the bumps?
A. Bruising from Rejuran typically fades on a similar timeline, within about 72 hours. In an expert consensus for a related PN product, ice wraps during treatment helped reduce bruising, and bruises were less common with a cannula than a needle. If a bruise lasts over a week or keeps spreading, let your provider know.
Q. Can hyaluronidase dissolve a Rejuran nodule?
A. There's no evidence we could find that hyaluronidase dissolves a Rejuran nodule. Hyaluronidase is an enzyme that breaks down hyaluronic acid, so it's used for lumps from hyaluronic acid boosters. Granulomas are sometimes treated with steroid injections or oral medicine, so the cause is identified first.
Q. Should I get a lump checked if it shows up months after Rejuran?
A. Yes, a new lump months after Rejuran is worth having examined. Reports linking PN to late nodules are hard to find, but long-term data are limited. With fillers, nodules have appeared weeks to years later, so note when it appeared and whether it's growing.
Treatment guide for this topic
Jangju Kim Senior Director
JANGJU KIM
Dr. Jangju Kim is a clinic director at STON Clinic, LOTTE HOTEL in Myeongdong.
Career / Education
- 현) 스톤클리닉 명동 롯데호텔 원장
- 경희대학교 의과대학 졸업
Comments