Needle or Microneedle? How Skin Boosters Are Delivered in Korean Clinics
Regenerative skin boosters built on PDRN and PN have to be placed into the skin, because the molecules cannot pass through intact skin on their own. Korean clinics do this in two main ways: injecting small deposits point by point with a needle, or spreading the product across the area with microneedling devices, the route a booster such as ELREJU is designed for. The two feel different and leave different short-term marks, but neither is simply better; which one suits you depends on what needs treating, at what depth, and is a decision for a doctor's examination.
Why Delivery Matters for Skin Boosters
Regenerative skin boosters are built around polynucleotides, PDRN and PN, which are DNA fragments usually derived from salmon. They are used to support the skin's own repair rather than to add volume. Because the molecules are far too large to cross intact skin, they have to be placed into it, and how that happens decides much of what you feel on the day and what your skin looks like afterwards.
There are two main routes. With injection, the practitioner places a series of small deposits into the upper skin with a fine needle or an injector device, so the amount and depth at each point are controlled. With microneedle-assisted delivery, fine needles create many tiny channels at a set, shallow depth while the product is spread across the surface, so it is distributed in very small amounts over the whole area.
Comfort matters here for a practical reason. Boosters work over a course of sessions, and a course that is not finished does not do much. If you already know how you handle needles and downtime, say so at the consultation; it is part of choosing the right plan, not a weakness.
What Is in ELREJU, and How It Is Applied
ELREJU is a Korean clinic booster designed for the microneedle route. According to the manufacturer, it comes as two vials that are mixed just before use.
- Vial 1: a freeze-dried powder containing PN and PDRN, with tranexamic acid and madecassoside.
- Vial 2: a solution of high and low molecular weight hyaluronic acid.
- Compatible tools: a microneedle therapy system, the pumping tips used with radiofrequency microneedling devices such as Potenza, or a needle-free jet injector.
The idea is to treat overall skin quality across an area, hydration, texture and tone, in one session rather than to concentrate product in a few spots. Most people notice redness and warmth on the day rather than raised bumps, and this usually calms within a day or two. Experience still varies with skin sensitivity, the device and the settings, and some redness should be expected. If you are curious about how the regenerative ingredients themselves compare, our explainer on PDRN and PN skin boosters covers the science.
Injection or Microneedle: How the Two Routes Differ
Both routes are in routine clinical use in Korea, and they answer different needs. The table below sets out the usual differences; it is a guide to the questions to ask, not a ranking.
| Injection (needle) | Microneedle-assisted delivery | |
|---|---|---|
| How product is placed | Defined amounts at defined depths, point by point | Spread in small amounts across the whole area |
| Depth control | Precise, and able to reach slightly deeper | Controlled by the device, usually shallower |
| Typical sensation | Stinging or pressure at each point, even with numbing | Heat, pressure and a scratchy feeling |
| Usual short-term marks | Small raised bumps for a few days, possible pinpoint bruising | Redness, warmth and tightness, possible pinpoint marks |
| Often chosen for | Concentrating product where a doctor wants it | Even improvement in skin quality across an area |
PN injectables such as Rejuran are the most widely recognised example of the needle route; our guide to Rejuran in Korea explains how they are used. Radiofrequency microneedling is its own treatment as well, and our guide to Potenza covers what the device does when it is used on its own.
Visitors whose main goal is overall hydration and texture, who are new to regenerative treatments, or who cannot fit several days of visible bumps around a trip often end up on the microneedle route. People whose doctor wants product concentrated in particular areas often end up on the needle route. Which applies to you is decided at examination, not from a table.
What Neither Route Can Do
Changing the delivery method does not change what polynucleotides do. Neither route lifts sagging skin, replaces lost volume or acts faster than the skin's own repair allows. Change builds gradually over weeks, which is why boosters are planned as a course, commonly a few sessions several weeks apart, followed by occasional maintenance. Results vary from person to person and are not permanent.
Neither route is free of sensation or risk. Microneedling still breaks the skin surface, and injection still means many needle entries. Radiofrequency microneedling in particular is a medical procedure: the US FDA has stressed that these devices should be used by a trained, licensed provider and not at home. In Korea, that means a treatment carried out at a clinic after a doctor's assessment.
Some people should wait. Treatment is generally avoided during pregnancy and breastfeeding, over active acne, cold sores, infection or inflamed skin, and on sunburned skin. A history of keloid scarring, an autoimmune condition, a previous reaction to an injectable or recent isotretinoin use needs to be raised first, and so does a fish allergy, since most polynucleotides are salmon-derived. Afterwards, keep the routine simple, skip saunas and jjimjilbang for the rest of the day, and use sunscreen every day.
Dr. Beau's Note
Ask what sessions two and three look like before you agree to session one. Boosters are often booked one session at a time, which nudges everyone to treat the first appointment as the whole decision. It is not. The biology needs the full course, and the route you can actually stick with is worth more than the one that sounds strongest on paper. If a clinic can only describe the plan one session deep, notice that.
This is general information, not a substitute for a qualified practitioner's examination and advice.
