Rejuran Korean Skincare on a Short Seoul Trip, From the Serum on Your Shelf to the Injection

I'm Dr. Hyunji Kim, Director and Lead Physician at Delphic Clinic, on the second floor of the Urban Hive building at 476 Gangnam-daero in Seoul. My background is Korea University Medical Center, and I'm a member of the Korean Academy of Aesthetic Surgery & Laser Medicine, the Korean Society for Laser Dermatology & Hair and the Korean Filler Society.

"Rejuran Korean skincare" is a phrase I hear regularly in my consultation room, often from travelers who already use a Rejuran serum at home and have a few days in Seoul, and it arrives with two different meanings. Some people mean the creams and serums sold under the Rejuran name. Others mean the Rejuran injection, which places polynucleotide (PN) into the skin with a needle and comes with about 1–3 days of downtime that your trip has to absorb.

In short

• The Rejuran name covers both shop skincare and a clinic injection; only the injection delivers PN below the surface.
• Expect about 1–3 days of small bumps and redness after the injection, so it belongs early in a trip.
• The recommended gap between sessions is 2–3 weeks, so a short trip fits one session, not a course.
• If your skin is calm and your home routine works, you don't need to book anything.
• At Delphic, consultations are interpreted in English, the doctor performs the injection, and same-day treatment is possible after the consult.

Is Rejuran a skincare product or an injection?

Both carry the name, and they work at different depths. The injection is a medical injectable made from polynucleotide derived from salmon DNA, placed into the skin by a doctor. The serums and creams are cosmetics you apply yourself.

Our clinic's treatment notes describe the injected material as biocompatible and aimed at the epidermal and dermal layers, the two layers where texture, fine lines and thinness show. That is the reason people fly in for the needle version rather than buying another bottle. The longer background on the injection is in my Rejuran overview.

In a Seoul shop you can hold a jar with the same name you saw on a clinic menu that morning. On a short trip, knowing which one you came for decides whether you need a clinic visit at all.

What can a Rejuran serum actually reach?

The surface. Intact skin is built to keep large molecules out, and a widely cited rule of thumb holds that compounds above roughly 500 daltons generally struggle to pass through it (Bos & Meinardi, Experimental Dermatology, 2000). Polynucleotide is a chain of DNA fragments, far above that size.

So a serum can hydrate and make skin feel comfortable, which helps in a dry hotel room. It is not a stand-in for PN placed in the dermis. Keep using it if you like it; just don't judge the injection by what the bottle did, or the other way round.

Healer, I, HB, S: which letters are worth asking about

The letters mark different versions in the same product family, and which one goes into your skin is a decision made while looking at it. On our menu, Rejuran Healer is the version used across the face, and Rejuran Eye is the one for the thin skin under the eyes.

Rejuran I appears on our menu as its own item; the name is commonly linked to the eye area too, and which of the two fits is settled at the exam.

You'll also see HB, HB Plus and S mentioned online. Rejuran HB is generally described as a formulation that includes a local anaesthetic and has a slightly different texture, and HB Plus is presented as an updated version of it. Rejuran S is generally described as aimed at depressed scars, such as indented acne scars.

Instead of picking a letter at home, bring the problem: crepey under-eyes, rough texture on the cheeks, dull tone after a long winter. The area and the problem decide the version. Our menu also has Rejuvelook, which combines Rejuran 3cc with Juvelook Skin 2cc in one session.

If you're also weighing salmon PDRN against Rejuran, I compared the two in salmon injection or Rejuran for your skin.

What happens on the day of a Rejuran injection?

A consultation, a close look at bare skin, then the injection, often all on the same day. The clinic sits by Exit 3 of Sinnonhyeon Station (Line 9 and the Shinbundang Line), so from a Gangnam hotel it is a short ride.

What I look at before deciding:

• Thickness. Under the eyes and along the cheeks, I check how thin and crepey the skin is when it moves. Thin, fine-lined skin is where PN makes the most sense.
• Active inflammation. Red, inflamed acne, a cold sore, or rosacea that is flaring right now usually means waiting.
• Recent procedures. A laser or peel in the last few days changes the plan.
• The real complaint. If the mirror problem is a jawline that has dropped, that is a lifting question, and Rejuran is not a lift.

The injection itself is many small injections across the area, which leave small raised bumps. Those bumps and some redness are the 1–3 days of downtime our treatment notes list.

How many days does a short Seoul trip need around Rejuran?

Plan at least two to three days after the session before anything where your face matters, such as a wedding, a work presentation or photos. That makes the first half of your trip the right place for it.

Hours matter for travelers. We see patients Monday to Friday 10:30–21:00 and Saturday 10:30–17:00, and we're closed on Sundays. If you land on a Sunday, your earliest visit is Monday; if you land on a weekday afternoon, an evening visit is realistic, depending on availability.

The catch on a short trip is the interval. One session is a start. If you can't come back within a few weeks, that's fine, but set your expectations by one session.

Who Rejuran doesn't suit, and the side effects to plan for

Most reactions are local and short: redness, small bumps along the injection lines, tenderness, and sometimes a bruise. A 2025 systematic review of polynucleotides in aesthetic medicine described side effects in the included studies as mostly mild and temporary, while noting that larger, more rigorous trials are still needed (Lampridou et al., Journal of Cosmetic Dermatology, 2025).

It is reasonable to postpone or skip Rejuran if:

• you have a known allergy to fish or salmon products (tell the doctor before anything is opened);
• you are pregnant or breastfeeding, since data for this group are limited;
• the area has active infection, a cold sore or inflamed acne;
• you take blood thinners, which raise the chance of bruising (don't stop them on your own);
• you have an event or photos within the next two to three days.

Individual skin varies, and the in-person exam decides whether it's suitable for you. How visible the bumps are, how long redness lasts and how your skin responds over the following weeks differ from person to person.

When you don't need to come in for this

You don't need a clinic visit if your skin is calm and your current routine is working; keep the serum and enjoy the city. You also don't need Rejuran if your main concern is sagging along the jaw, because that calls for a different kind of treatment.

Skip it on this trip if you only have one full day and a big event right after, or if you are hoping one session will change your skin dramatically by the flight home. The common disappointments people describe usually come from mismatched expectations, which I wrote about in the three complaints I hear most about Rejuran.

A five-line self-check before you message

Run through these before you contact any clinic about Rejuran, including us:

• Can I name the one thing I want changed (texture, under-eye crepiness, dull tone)?
• Do I have two or three days after the session without an event where my face matters?
• Is my skin calm right now, with no active breakout, cold sore or recent peel?
• Have I checked for a fish allergy, pregnancy or blood thinners?
• Am I fine with one session being a start rather than a finished result?

If you answered yes to all five, a consultation makes sense. If not, the answer may simply be "not this trip".

Clinic hours, location and the full treatment menu are on the Delphic Clinic English site. To start, send your travel dates and the one thing about your skin you'd like changed on WhatsApp. When you visit, the 1:1 consultation is interpreted in English, and the clinic is right by Exit 3 of Sinnonhyeon Station.