Half of those who come to get Rejuran only know it as a "salmon injection"

These days, because of all sorts of news, the world outside the clinic feels quite chaotic too.

Anyway, let’s get to the main point.

As the seasons change, the clinic gets noticeably busier,

There are so many complaints about dryness, dehydration, and inner dryness

really a lot~ ~

Even though the number of people looking for Rejuran has decreased,

about the ingredient PN,

they ask like this.

"Rejuran is the one extracted from salmon, right?"

That’s true, but in fact, that’s not all of it.

Today, I’ll walk you through what’s inside, step by step.

So what exactly is different about it?

Rejuran’s main ingredient is PN,

a substance called polynucleotide.

The name is difficult, but simply put,

it’s a fragment made by breaking DNA into tiny pieces.

What makes this a bit tricky is that,

unlike hyaluronic acid fillers, PN

isn’t an ingredient that adds volume.

It enters the skin

and plays a role in stimulating cells to recover on their own.

So it’s closer to "revive" than "fill."

Why do some people get less of an effect?

The key point of this article

Rejuran’s PN (polynucleotide) came from salmon? We’ll explain the ingredient and its mechanism of action in simple terms.

Rejuran PN really comes from salmon


More precisely, it is PN made by extracting and purifying DNA from the germ cells (testes) of salmon and trout,


then breaking it into small pieces in a size suitable for human skin.


The key point is that it is over 95% structurally similar to human DNA,


so there is almost no rejection response.

Last month, a patient in her mid-40s came in,

after getting Rejuran three times elsewhere

and came in disappointed, saying, "I don’t really see a difference."

When I looked at her skin, the problem wasn’t the ingredient but the injection depth.

There were signs it had been injected too superficially.

The molecular weight of PN is roughly 50 to 1,500 kDa,

much smaller fragments than hyaluronic acid.

It needs to be placed into the dermis, at about 1.5 to 2.0 mm deep,

to stimulate fibroblasts

and boost collagen and elastin synthesis.

If it’s too shallow, it’s just absorbed in the epidermis and that’s it,

and if it’s too deep, the stimulation gets dispersed.

But here’s one important thing.

PN is not an ingredient whose effect shows up the moment it goes in.

Over 2 to 3 weeks, as cells respond,

the skin texture gradually improves.

So rather than one session, accumulating 3 to 4 sessions at 3- to 4-week intervals is important.

Director Wi Youngjin’s key summary


Rejuran PN is a regenerative substance extracted from salmon DNA,


and it works by awakening skin cells rather than filling them.


So depth and the number of sessions determine the results.

This is how I break it down in the clinic

It differs by case,

but PN-based procedures also vary quite a bit

depending on the skin condition.

But it’s not all good.

For 1 to 2 days after injection, bumpy wheals remain,

and quite a few people also bruise.

Still, once recovery happens, texture improvement

is felt more quickly than with other regenerative procedures,

so it’s still a good option for thin skin like around the eyes and cheeks.

The three questions I get most often in the clinic

Q1. If I have a salmon allergy, can’t I get it?

A. This is a common misconception,

PN is not salmon flesh or roe, but

refined DNA fragments.

Most of the proteins have been removed,

so it is considered separate from salmon allergies.

However, please be sure to tell us in advance during the consultation.

Q2. How many times do I need it, and how long does it last?

A. Usually the basic course is 3 to 4 sessions at 3- to 4-week intervals,

and after that, maintenance once every 6 months is recommended.

Many people say after just one session, "It doesn’t seem like much,"

but honestly, it’s hard to judge from one session.

The cumulative response needs to build up for the texture to improve.

Q3. Is there anything I should be careful about after the procedure?

A. Avoid saunas, alcohol, and strenuous exercise on the day of treatment,

and wheals may remain for 2 to 3 days.

You can wear makeup starting the next day,

and bruising usually fades within a week.

We recommend that you discuss it thoroughly before deciding.