Rejuran in Hanoi, performed by our doctor

What Rejuran is

Rejuran is made by PharmaResearch in South Korea. The company describes it as a medical device for the temporary improvement of facial wrinkles, made from PN (polynucleotide) extracted from salmon with a patented process it calls DNA Optimizing Technology.

The PN is placed directly into the dermis, the layer just under the surface of the skin, with the aim of improving the skin environment overall. What that looks like on your face is something the doctor tells you after seeing your skin.

PharmaResearch also notes that PN is thick and can make the injection uncomfortable, which is why it makes a version with a local anaesthetic mixed in. Ask the doctor how comfort is handled at your session.

Rejuran or Rejuran S?

PharmaResearch lists four products: Rejuran, for the whole face; Rejuran i, for the thin skin around the eyes; Rejuran S, which it describes as effective in reducing wrinkles and scars; and Rejuran HB plus, the version with a local anaesthetic. We offer Rejuran and Rejuran S.

The doctor picks between the two by what you want to change. A tired or uneven surface points to Rejuran. Fine lines and the look of old scars point to Rejuran S.

How many sessions?

In a PharmaResearch press release from April 2024, a physician says Rejuran is dose-dependent, and that repeated sessions (three to four) increase the effect. That is one doctor's view, not a rule for your skin.

A 2026 expert article by advisers to the maker suggests three sessions at four-week intervals for skin hydration and rejuvenation. Here the doctor sets the number after looking at your skin, and you know the total before the first session. Ask for the whole plan first.

What the research says

A 2025 systematic review of nine studies (219 patients, low to moderate quality) found that polynucleotide injections reduced wrinkles and improved texture and elasticity in several of them, with mild side effects. It covers polynucleotide treatments in general, not Rejuran alone, and its authors call for better trials.

A 2026 expert-opinion article on Rejuran, written by physicians on PharmaResearch's advisory board with two PharmaResearch employees among the authors, says the evidence base remains limited and that randomised trials are needed.

Who Rejuran suits

If acne scars are your main concern, our acne scar page sets out the other options, and the doctor can combine them with Rejuran S.

• Skin that looks tired or uneven in texture
• Fine lines and the look of old scars
• People happy to plan a short course of sessions rather than a single visit

When it is better to wait

Tell us first. The doctor may ask you to wait, or to check with your prescriber first, if any of these apply:

• You are pregnant or breastfeeding.
• The skin in the area is infected, blistered, broken or sunburnt, or inflamed acne is spreading and painful there.
• You have had a peel, laser or microneedling in the last two weeks.
• You take oral acne medication, or stopped it less than six months ago. Check with your prescriber first.
• You have had an allergic reaction to an injectable product before. Tell us before the consultation.
• You have a fish allergy. The PN comes from salmon, so mention it before the consultation.

After the session

Expect a light stinging feeling during the injection and some redness afterwards. Our usual advice is to skip make-up for three days, avoid saunas and strong sun for the first 24 hours, wear sunscreen from then on, and pause AHA, BHA and retinol for the first week. You get written aftercare for your session.

If you are in Hanoi for a short stay, book early in your trip so a second session is still possible before you leave.