Rejuran (PDRN) in Korea: What It Is, FDA Status

If you have scrolled past what TikTok calls the "salmon sperm facial," or heard cousins in Seoul talk about Rejuran, you have probably wondered what is actually in it — and why you can buy a PDRN cream at a US counter but not get the injections your relatives are getting in Korea. If you read labels for a living, the loose way these terms get mixed together online is exactly the problem.

Here is the short answer first. Rejuran is a salmon-DNA skin booster — a biostimulator, not a filler, so it does not add volume the way a hyaluronic-acid filler does. The injectable form is not FDA-approved in the US; it is authorized for sale in Korea under the MFDS*. Topical PDRN products sold in the US are a different category entirely.

This is general information from BeautyStone, a skin clinic in Hongdae, Seoul — not a substitute for a clinician who has examined your skin.

What you'll learn

  · What Rejuran, PDRN, and PN* actually are, and how they differ from a filler
  · How salmon DNA is thought to work on fibroblasts and collagen
  · What the clinical evidence shows so far, and how strong it is
  · The US FDA picture versus the Korea (MFDS) picture, topical versus injectable

What Rejuran and PDRN actually are (and what they are not)

The names get used interchangeably, but they are not identical. Both are DNA-derived molecules purified from salmon, cleaned of the proteins and peptides that could trigger an immune reaction. The difference is chain length. A narrative comparison of the two describes polynucleotide (PN) as longer DNA chains from fish gonadal tissue, while PDRN is a shorter-chain, pharmacologically active fragment, with PN behaving more as a structural, water-holding scaffold and PDRN as the molecule with a defined receptor mechanism. Rejuran's active is usually described as PN; "PDRN" is the broader label the market uses for the whole salmon-DNA family.

PDRN*(polydeoxyribonucleotide): short DNA fragments purified from salmon, used to prompt tissue repair and collagen activity.

PN*(polynucleotide): longer salmon-DNA chains that also hold water and give the gel its structure. Rejuran's main ingredient.

What it is not is a filler. A filler sits in a pocket and holds a shape; a skin booster like this is placed shallowly across the dermis to nudge the skin's own repair machinery, with change building over several sessions rather than appearing the moment it is injected.

Here is how the two salmon-DNA boosters line up against a hyaluronic-acid (HA) skin booster — a different category people often lump in with them:

Skin booster	What it is	How it works	Onset & sessions	Downtime	US regulatory status
PN (Rejuran's active)	Longer purified salmon-DNA chains	Holds water and signals fibroblasts to remodel the dermis	Gradual; a short course spaced weeks apart	Minor bumps, redness, occasional bruising for a few days	Injectable not FDA-approved in the US
PDRN	Shorter salmon-DNA fragments	Activates the A2A receptor to drive repair and collagen	Gradual; usually a short course	Mild and transient, similar to PN	Injectable not FDA-approved; topical PDRN cosmetics sold legally
HA skin booster	Hyaluronic acid, not DNA	Draws and holds water to hydrate and soften texture	Some hydration quickly; repeat sessions common	Similar microinjection effects	One HA microdroplet booster is FDA-approved (a different product)

How it works: the A2A receptor and collagen

The mechanism is more specific than "salmon DNA heals skin." A review of PDRN for skin repair explains that PDRN is derived from salmon or trout DNA and acts largely by activating the adenosine A2A receptor, which drives VEGF production, new vessel formation, and fibroblast activity that accelerates collagen and tissue repair. In plainer terms, the fragments do two jobs: they hand fibroblasts spare nucleotide building blocks, and they flip a receptor switch that turns down inflammation and turns up the signals that build collagen.

Adenosine A2A receptor*: a cell-surface switch that, when activated, reduces inflammation and encourages new blood vessels and collagen.

That is why the effect is gradual, and why one session rarely tells you much. The skin is being asked to remodel itself, and that takes weeks.

What the evidence actually shows so far

This is the part worth reading slowly, because the marketing runs ahead of the data. A systematic review of polynucleotides in aesthetic medicine pooled nine studies of low-to-moderate quality covering 219 patients, and found reduced wrinkles, improved skin texture, and better elasticity with statistically significant results in several studies, alongside mild and transient side effects and moderate-to-high satisfaction. The same review is candid that most studies came from Korea and that higher-quality trials are still needed to draw firm conclusions.

A separate dermatology review reaches a similar place, noting these are promising DNA-derived agents but that more controlled studies are needed to close the gaps in evidence and standardize dosing and protocols. So the honest framing is early evidence, trending positive, not settled. Individual results and recovery vary with skin thickness, age, and technique, so treat any before-and-after you see as one person's outcome rather than a rule.

Reported side effects are mostly what you would expect from any microinjection — temporary swelling, redness, small injection bumps, and occasional bruising that settles over a few days.

So can you actually get it: the FDA question

Here the topical-versus-injectable split matters, and it is where the online chatter is most misleading. In the US, cosmetics do not go through FDA premarket approval, so a topical PDRN cream or serum can be sold legally as a cosmetic for external use only. That legality says nothing about the injections. An injectable placed into the dermis to change the skin's structure is not a cosmetic in the regulatory sense; in the US it would need FDA clearance or approval as a device or biologic, and injectable Rejuran/PN skin boosters do not have that. So the accurate statement is: not FDA-approved in the US as an injectable; available in Korea, where Rejuran is authorized for sale under the MFDS.

MFDS*: Korea's Ministry of Food and Drug Safety, the regulator that authorizes drugs and medical products for the Korean market.

Two footnotes for the careful reader. First, a topical cosmetic's legality cannot be stretched into an injectable claim — different route, different rules, different evidence. Second, the FDA has approved a hyaluronic-acid microdroplet skin booster (a different product, not a PDRN one), which shows the category is not banned, only that this specific molecule has not cleared that bar in the US yet.

If you are flying to Seoul for it: the visit and flying home

Here is the realistic timeline, first visit through the full course:

• Day 0 — the visit. A numbing step, then a series of shallow microinjections. Most people walk out the same day with minor bumps and redness.
• The first few days — recovery. Swelling, redness, small injection bumps, and occasional bruising settle over a few days. This is where the fly-home question lands: usually you can fly about three days later since downtime is small, but bruising can linger, and a long-haul flight is not the moment for a fresh bruise to surface — if your schedule allows, leave a few clear days between the last session and the flight.
• Weeks after — gradual peak. The change builds as the skin remodels itself, so one session rarely tells you much.
• The full course — repeat. It is usually a short series spaced a few weeks apart, with the effect accumulating across sessions rather than landing all at once.

The honest limitation of any procedure done abroad is aftercare: if a delayed reaction or complication shows up once you are home, you will likely need local follow-up where you live, since the clinic that treated you is now an ocean away.

On cost, clinic price menus in Seoul commonly list a single Rejuran session in the ₩200,000–₩500,000 range — very roughly $150–$370, depending on the amount used, the area treated, and the exchange rate — though menus vary widely and packages change the math, so treat any figure as a ballpark and confirm directly rather than trusting a screenshot.

Who this is reasonable for — and who should skip it. It is a reasonable fit if you want gradual texture and skin-quality changes, can commit to a short series of sessions, and accept that this is not a filler and will not add volume or erase deep lines. You should probably skip it if you want a single dramatic result, cannot come back for repeat sessions, or are pregnant or breastfeeding (clear that with your own clinician first). The realistic payoff is subtle, cumulative improvement over a course — not a one-visit transformation.

One practical friction to settle in advance: if you are booking from abroad and English is a concern, ask directly about English-language support and what a session includes when you make the appointment — many Seoul clinics in tourist-facing areas field questions by email or a messaging app, but confirm the arrangement when you book rather than assuming it. Beyond that, look for a provider who examines your skin and explains what PN can and cannot do. This is general information, not medical advice — talk it through with a licensed clinician who has examined your skin before you decide.

Frequently asked questions

Q. Is Rejuran the same thing as the "salmon sperm facial"?

A. It comes from the same place — salmon DNA — which is where that nickname comes from, but the phrasing is a social-media label, not a clinical one. Rejuran refers to the injectable skin booster whose active is polynucleotide (PN), a purified salmon-DNA molecule. The topical "salmon DNA" creams you see online are a separate, external-use product and should not be treated as the same thing as the injections.

Q. Is Rejuran FDA-approved in the US?

A. Not as an injectable. Injectable Rejuran/PN skin boosters are not FDA-approved in the US. Topical PDRN cosmetics can be sold because cosmetics do not require FDA premarket approval, but that does not make the injectable version approved. In Korea, Rejuran is authorized for sale under the MFDS, which is a different regulatory system from the FDA.

Q. How many sessions does it take, and how long does it last?

A. It is usually given as a short course spaced a few weeks apart, because the effect builds gradually rather than appearing at once. How long the change holds varies from person to person and is not something anyone can promise a fixed number for. A provider who has seen your skin can give you a realistic range for your case.

Q. Does it hurt, and what is the downtime?

A. Most clinics numb the area first, and the discomfort is usually described as mild stinging from the microinjections. Common after-effects are temporary redness, small bumps, and occasional bruising that settle over a few days. If you notice spreading redness, worsening pain, or signs of infection, contact a provider or seek urgent care rather than waiting it out.