Part 3 — PDRN series
Our PDRN article covered the substance itself. A third question keeps arriving: where does Rejuran fit into all this? The answer is simpler than most people expect.
There’s a confusion that comes up constantly in clinic, and it’s entirely understandable:
One patient asks for Rejuran. Another asks about salmon injections. A third asks about PDRN.
Most of the time, all three are describing roughly the same thing.
So let’s untangle it.
The short answer
Rejuran is a Korean brand name for a product whose active ingredient is PDRN — fragments of DNA extracted from salmon and purified to a high grade. “Salmon injections” or “salmon DNA” are the common names for the same family. So: PDRN is the substance, and Rejuran is one brand containing it. Exactly as Botox is a brand and the substance is botulinum toxin.
Why salmon?
A very reasonable question, and usually asked with some surprise.
The reason is purely scientific: the DNA structure of salmon is closely comparable to human DNA, with a high degree of similarity. That means the body accepts it without meaningful immune rejection.
Before use, the material passes through purification stages that remove the proteins capable of causing allergic reactions. So what is ultimately injected isn’t “fish” — it’s purified DNA fragments.
What does it do in the skin?
PDRN acts on specific cell receptors (adenosine receptors), producing three main effects:
Fibroblast stimulation — the cells that produce collagen and elastin. Reduced inflammation — which makes it particularly useful for sensitive, reddened skin. Improved blood supply — so the skin is better nourished.
The combined result: skin that repairs itself more efficiently.
Not filling. Not an instant lift. Repair.
What does it actually help with?
From what I observe in clinic, the best responses come with:
Sun-damaged skin that has lost its smooth texture. Chronic redness and sensitive skin. Enlarged pores. Fine lines still at an early stage. Dull skin that hasn’t responded sufficiently to standard hydration. Light superficial scarring, as part of a broader plan.
It doesn’t help with: visible laxity, volume loss, or deep static wrinkles. Those need entirely different tools.
Rejuran compared with the alternatives
| Rejuran / PDRN | Skin booster (HA) | Exosomes | |
|---|---|---|---|
| Substance | Salmon-derived DNA | Hyaluronic acid | Cell-signalling vesicles |
| Aim | Skin repair | Deep hydration | Stimulation by signalling |
| Results appear | 4 – 6 weeks | 1 – 3 weeks | Weeks, variable |
| Evidence maturity | Moderate, growing | Most established | Newest, thinnest |
| Sessions | 3 – 4 | 3 | Depends on protocol |
| Characteristic side effect | Bumps for 1 – 3 days | Milder bumps | Depends on paired procedure |
Dr. Rehab Zakaria’s advice: “When someone asks for Rejuran by name, I ask them: where did you hear about it, and what are you trying to solve? Sometimes it genuinely is the right choice. Sometimes the patient needs simple hydration, and it’s the brand name that brought her in rather than the problem. I don’t inject names — I inject solutions.”
How the session works
Cleansing, then topical numbing cream for 20 to 30 minutes. The product is then injected at precise points across the target area, in small amounts at each point.
The session takes 20 to 40 minutes depending on the area.
You’ll see small bumps at each injection point immediately afterwards. These are entirely normal with PDRN specifically — slightly more pronounced than with a standard skin booster — and resolve within one to three days.
Aftercare
Don’t touch or massage the area for the first 24 hours. No makeup for at least 12 hours. Avoid saunas, intense exercise and hot baths for two days. Daily sun protection from day two — and that isn’t optional.
The bumps will settle on their own. Don’t press or squeeze them.
What is not expected: severe pain, redness increasing after day three, or warmth in the area. Contact your doctor straight away if any appear.
Who isn’t a candidate?
We postpone or decline in: pregnancy and breastfeeding. Known fish allergy — which must be disclosed beforehand even though purification reduces the risk. Active infection or inflammation at the injection site. Unstable autoimmune conditions. Clotting disorders or blood thinners without medical coordination.
A practical point: how to confirm the product is genuine
Well-known Korean products are widely counterfeited, so this matters:
Ask to see the packaging before it’s opened. Ask for the name of the importing company. Check the expiry date. And ask how the product is stored at the clinic.
A reputable clinic won’t be remotely bothered by those questions.
Frequently asked questions
Is Rejuran better than ordinary PDRN?
Rejuran is PDRN. The meaningful comparison is between brands — concentration, preparation and price — not between “Rejuran and PDRN.”
Can I have it with Botox or filler?
Yes, and it’s common. Sequence and timing depend on the areas involved.
Does it hurt?
With numbing cream it’s tolerable. Some patients describe it as slightly less comfortable than a standard skin booster.
How long do results last?
Usually 6 to 12 months after completing the protocol, varying with age, lifestyle and sun protection.
Can I have it a week before an event?
Not ideal, because of the bumps and redness. Plan at least a month ahead, preferably two so you also see the result.
The bottom line
Rejuran and salmon-DNA injections are neither mysterious nor miraculous — they are simply PDRN-based products that work by prompting the skin to repair itself.
They’re a good option if your problem is skin quality: texture, redness, pores, fine lines. They are not the option if your problem is volume or laxity.
And most importantly: choose based on the problem, not on the brand name you saw on Instagram.
At Dr. Rehab Zakaria’s clinic in El Tagamoa, New Cairo, we explain the difference between substance and brand before any decision — so you know exactly what you’re paying for.
To book or ask a question: WhatsApp 01064022402.
Disclaimer: This article is for general medical education and is not a substitute for medical consultation. Any aesthetic procedure should be preceded by an individual assessment from a qualified doctor.
Continue the series
- Part 1: what PDRN is — the foundation
- Part 2: PDRN before and after — the real results timeline
- Part 4: exosomes for skin — compared with the next tier
Still deciding between treatments?
The complete guide covers every type of aesthetic injectable, how they differ and when to use each, with a full comparison table, pricing and clinic-selection criteria.
Dr. Rehab Zakaria
Clinic & beauty consultant
Consultant in Dermatology, Cosmetic, and Laser
Master’s and Doctorate in Dermatology and Laser Diseases
Certified Trainer
Master Injector