What Are the Possible Side Effects of Rejuran Injections?

October 25, 2026

Rejuran is one of the most popular skin boosters in Korea, and many visitors to Busan want to try it while they are here. Because it is injected as many small deposits across the face, it does leave visible signs for a short time, and it is worth knowing what is normal, what is uncommon and what needs attention. This guide walks through the possible side effects of Rejuran Healer and Rejuran HB, who should avoid them, and how to plan around your trip.

Quick answer: The most common side effects of Rejuran are small raised bumps at the injection points, redness, mild swelling, tenderness and needle marks, which usually settle within 1–2 days. Some people also get small bruises that fade over several days, more often under the eyes. Rarely, infection, allergic reaction or persistent lumps can occur, so contact the clinic if anything worsens rather than improves. Rejuran is not suitable if you are allergic to fish or salmon-derived ingredients, pregnant or breastfeeding, or have an active skin infection in the area.

What is Rejuran, and why does it cause bumps?

Rejuran is a family of skin boosters made by PharmaResearch, a Korean company. The core ingredient is PN (polynucleotide), a DNA-derived ingredient purified from salmon that is used to support the skin's own repair processes. Rejuran Healer focuses on repair, elasticity and texture, while Rejuran HB adds hyaluronic acid for extra hydration. A dedicated eye version is used for the thin under-eye skin.

The product is placed in many small, shallow deposits. Each deposit lifts the skin slightly, creating a small bleb or bump. This is expected and is part of how the treatment is delivered, not a reaction. The bumps flatten as the product spreads and is absorbed, usually within hours to a day.

PN boosters have a growing body of research, mostly small clinical studies, suggesting improvements in skin quality. Evidence is less extensive than for long-established treatments such as Botox or hyaluronic acid fillers, and results vary. Claims that salmon DNA "regenerates" skin dramatically go beyond what has been proven.

Common side effects

  • Small bumps at the injection points. Usually most visible for the first few hours and settled within a day.
  • Redness and mild swelling. Often settles within 1–2 days. Swelling can be more noticeable under the eyes.
  • Needle marks. Tiny pinpoint marks that fade over 1–2 days.
  • Tenderness or stinging. PN boosters can sting a little more during injection than some other boosters, even after numbing cream. The area may feel slightly sore afterwards.
  • Bruising. Small bruises at some injection points, fading over several days. Thin skin and blood-thinning medications or supplements make bruising more likely.

Uncommon and rare side effects

  • Persistent lumps. Occasionally a small lump remains longer than expected. Most soften over time, but tell the clinic.
  • Infection. Any injection carries a small infection risk. Signs include increasing redness, heat, pain, pus or fever after the first day or two.
  • Allergic reaction. Rare, but more of a concern if you are allergic to fish. Signs include spreading hives, itching or swelling beyond the treated area.
  • Flare of cold sores. Injections near the lips can trigger cold sores in people prone to them; mention this at your consultation.

When to contact the clinic

Message the clinic, or seek medical care if you cannot reach them, if pain, swelling or redness is getting worse after 48 hours, if you notice pus, fever or a hot, hard area, or if you have signs of an allergic reaction. Difficulty breathing or swelling of the lips or throat needs emergency care straight away.

Who should avoid Rejuran or wait

  • People who are pregnant or breastfeeding
  • Anyone allergic to fish or salmon-derived ingredients
  • People with an active skin infection, cold sore or inflamed acne in the area
  • People with an uncontrolled autoimmune condition
  • People who tend to form keloid scars

Tell the doctor about all medications and supplements, especially blood thinners, and about recent fillers, lasers or other procedures in the same area.

How to reduce side effects: aftercare

  • For about 3–4 hours, avoid lying face-down and do not rub the treated area.
  • On the day of treatment, skip saunas, jjimjilbang, hot baths, strenuous exercise and alcohol.
  • Do not massage or press firmly on the treated skin.
  • Leave makeup until the next day where possible.
  • Keep the skin moisturised and use sunscreen when you are out.

Cost of Rejuran in Busan

In Seomyeon, Rejuran is usually offered in packages. A clinic there lists:

  • Rejuvelook (Rejuran 2cc + Juvelook Skin 2cc) : from KRW 319,000
  • Rejuran HB 2cc : from KRW 390,000
  • Rejuran 2cc + Juvelook Skin 2cc + hydration injection 2cc + full-face skin Botox : from KRW 590,000
  • CellREDM 7cc + Rejuran 2cc + LDM + hydrating mask : from KRW 690,000

Prices checked October 2026. They exclude 10% VAT, which is added at payment, and prices can change, so confirm the current price when you book. Three or more sessions 2–4 weeks apart are usually advised for the clearest change, so factor that into your budget if you can return to Busan.

Planning Rejuran around a trip

Most people carry on with their day after Rejuran, and flying is usually fine. The visible bumps mean it is best not to book it right before photos, a wedding or a special dinner. A practical plan is to have it early or in the middle of your stay, do light sightseeing the same afternoon with sunglasses if the eye area was treated, and leave the jjimjilbang for later in the trip. If you combine Rejuran with Thermage or other procedures, ask about any extra recovery time, and tell the doctor your flight date at the consultation.

Rejuran Healer vs Rejuran HB: are side effects different?

The side effect profile is very similar, because both are injected the same way and share the same salmon-derived PN base. Some patients find Rejuran HB a little more comfortable, but this is individual. Choose between them for your skin's needs: Rejuran Healer for repair and texture, Rejuran HB if dryness is also a concern.

Frequently asked questions

How long do Rejuran bumps last?

Usually a few hours to a day. Needle marks and mild swelling can last 1–2 days, a little longer under the eyes.

Can I have Rejuran if I am allergic to fish?

It is generally not recommended. PN is purified from salmon, so tell the doctor about any fish allergy and ask about alternatives such as hyaluronic acid boosters.

Does Rejuran hurt?

Numbing cream is applied for about 20–30 minutes first, so most people feel light pricking and pressure. PN boosters can sting a little more than some others, and you can ask for a break at any time.

Thinking about Rejuran in Busan?
Send a clear front photo, the areas you would like treated and your travel dates on WhatsApp to get a plan and today's price in English.

This article is for general information and does not replace a medical consultation. Suitability, results, recovery and side effects vary from person to person.

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