With everything in the news lately, the world outside the clinic feels quite hectic.

In any case, let's dive right into today's main topic.

As we transition between seasons, our clinic has been incredibly busy,

and we have been hearing so many concerns

about deep dryness and tight, dehydrated skin~ ~

Although the sheer volume of patients looking for Rejuran has settled slightly,

many are still asking

about its key ingredient, PN, like this:

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

You're absolutely right, but actually, that is not the whole story.

Today, I would like to gently walk you through what really happens behind the scenes.

What makes this so different?

The active ingredient in Rejuran is PN,

a substance known as Polynucleotide.

While the name sounds a bit complex, simply put,

they are tiny, purified fragments of DNA.

To clear up some common confusion,

unlike hyaluronic acid dermal fillers, PN is

not a component designed to add immediate volume.

Instead, once introduced into the skin,

it works by stimulating your cells to naturally repair and restore themselves.

So, rather than "filling," it is much closer to "regenerating."

Why do some people see less visible results?

The Key Point of This Article

Does Rejuran's PN (Polynucleotide) really come from salmon? Let's break down the science and how it works in an easy-to-understand way.

Yes, Rejuran's PN truly originates from salmon.


To be precise, it is created by extracting and purifying


DNA from the reproductive cells of salmon and trout,


and then cutting it into tiny fragments optimized for human skin.


The key is that its structure is over 95% similar to human DNA,


meaning there is almost no risk of rejection or adverse reactions.

Last month, a patient in her mid-40s visited our clinic.

She had previously received three sessions of Rejuran elsewhere

and was disappointed, saying she "couldn't really see a difference."

When I examined her skin, the issue wasn't the ingredient itself, but rather the injection depth.

There were traces showing it had been injected too superficially.

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

which represents much smaller fragments than hyaluronic acid.

These fragments must reach the dermis layer, at a depth of about 1.5 to 2.0 mm,

in order to successfully stimulate fibroblasts

and boost the synthesis of collagen and elastin.

If placed too shallowly, it simply gets absorbed by the epidermis and ends there;

if injected too deeply, the stimulation becomes scattered and lost.

However, there is another important detail to keep in mind.

PN is not an ingredient that shows instant dramatic results right after injection.

Instead, your skin texture gradually improves over 2 to 3 weeks

as your cells slowly respond and regenerate.

This is why a cumulative series of 3 to 4 sessions, spaced 3 to 4 weeks apart, is much more important than just a single treatment.

Dr. Wi Young-jin's Key Summary


Rejuran PN is a regenerative material extracted from salmon DNA.


Rather than filling space, it works by awakening your skin cells.


Therefore, the injection depth and cumulative session count are what determine your results.

How I categorize this in the consulting room

While it uniquely varies for every individual case,

our approach to PN treatments differs significantly

depending on your specific skin condition.

However, it's helpful to know about the minor downsides as well.

For 1 to 2 days immediately after the injection, bumpy embossing (papules) will remain,

and some patients may experience mild bruising.

Nevertheless, once the skin heals, the improvement in texture

tends to be much more noticeable compared to other regenerative treatments.

Because of this, it remains an excellent choice for thin, delicate skin, such as around the eyes and cheeks.

The Three Most Frequently Asked Questions in Our Clinic

Q1. Can I get this treatment if I have a salmon allergy?

A. This is a very common misconception.

PN is not made from salmon flesh or salmon roe;

it is a highly purified DNA fragment.

Since almost all proteins are completely removed during the process,

it is considered unrelated to a salmon food allergy.

However, please make sure to let us know during your consultation just in case.

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

A. Typically, a basic course of 3 to 4 sessions spaced 3 to 4 weeks apart is recommended.

After that, we suggest a maintenance session once every 6 months.

Many patients try it just once and feel it "doesn't do much,"

but honestly, it is difficult to judge after only one session.

The cumulative cell response needs to build up for your texture to truly change.

Q3. Are there any post-treatment precautions I should know?

A. Please avoid saunas, drinking alcohol, and strenuous exercise on the day of treatment.

Minor bumpy embossing may persist for 2 to 3 days.

You can apply makeup starting the very next day,

and any minor bruising usually fades within a week.

We always recommend having a thorough personal consultation before making your decision.