Why does Rejuran take more than one session?
“Can I just try one?” is a fair question. You can, but there is a reason it is offered as a course. Let us see where the number comes from.
The short answer
Rejuran’s “three sessions two weeks apart” is the count the approval phase 3 actually used. That is the count that produced the trial result, so there is no data saying one session gives the same. PN degrades gradually while it changes the environment, so repeated placement at intervals is built into the design. Clinics generally suggest three to four sessions three to four weeks apart.
Why one is not enough
PN does not make collagen through a foreign-body reaction. It forms a water-holding mesh that makes the skin’s own recovery easier, and that mesh degrades gradually. Place it once and the environment shifts briefly and then returns; place it again at intervals and the skin gets time to respond in between. That is why many people notice change around the second session.
Two weeks or three to four?
| Source | Sessions | Interval |
|---|---|---|
| Approval phase 3 (70 people) | Three | Two weeks |
| General clinic guidance | 3–4 | 3–4 weeks |
| Miso Clinic | Three as baseline, one more by condition | 3–4 weeks |
Two weeks is the trial protocol; three to four is a practical interval that lets swelling settle fully before the next session. The two have not been compared, so neither can be called better.
If you stop mid-course
No harm done. But the trial result was measured after three sessions, so stopping at one makes “it did not work” hard to judge. Pain is the most common reason people stop, and switching to HB Plus is the fix.
After the course
The phase 3 followed people for 12 weeks. Beyond that we decide by condition, not by data. If the skin is holding, there is no reason to add more; if it turns dry and rough again, many people top up with a single session. Condition, not calendar, as with every booster.
Which treatment fits which concern
| Concern | Treatments to consider | Why |
|---|---|---|
| Prefer a fixed course | Rejuran, three-session course | The trial set the count |
| One session first, then see | GOURI or Re2O, one session | Manufacturer default of one, or no protocol |
| Worried about pain over a course | Rejuran HB Plus | Contains lidocaine |
| Maintenance after a course | Single top-ups by condition | Condition, not calendar |
Which treatment is “best” is decided by the state of your skin right now, not by the product. In consultation we look first at what has been lost and what is still there, before we talk about any product name.
Frequently asked questions
Does one Rejuran session work?
No trial measured a single session separately. The result shown was after three.
I missed the interval and six weeks have passed.
No need to restart. Continue with the next session. Very long gaps may let the earlier environment return, though.
How many courses a year?
No long-term repeat data exists. Many people review about six months after a course, but that is clinical experience, not trial data.
Read next
If you want to go deeper
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Who wrote this
Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Studies are cited with their size and limitations, and where we could not find data we say so. Individual decisions need an in-person examination; this page does not replace one.
| Medical director | Lee Chi-Hak, MD |
|---|---|
| Address | 4F Bombom Building, 125 Dongdeok-ro, Jung-gu, Daegu, South Korea · Exit 1, Kyungpook National University Hospital Station |
| Phone | +82-53-428-2700 |
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| Hours | Weekdays 11:00–19:00 (lunch 13:00–14:00) / Saturday 10:00–16:00 / Closed Sundays and public holidays |
| Treatment guides | All guides |
| Comparisons | All comparisons |
| Columns | All clinical columns |
| Reference library | All booster and device references |
References
- Rejuran approval phase 3 trial — J Korean Med Sci 2014;29(Suppl 3):S201–S209 (Seoul National University Bundang Hospital). 72 enrolled, 70 analysed, randomised, double-blind, split-face, control was a hyaluronic acid product. Three sessions two weeks apart, 12-week follow-up.
- PharmaResearch product material — Rejuran Healer (PN alone), Rejuran HB (PN + HA), Rejuran HB Plus (PN + HA + lidocaine).
- Biomolecules 2025 — proposed molecular-weight boundary between PDRN (50–1,500 kDa) and PN (above 1,500 kDa).
Everything on this page is general information and does not replace medical diagnosis or treatment. Effects and side effects vary with individual skin condition, age and underlying illness, and the same result is not guaranteed for everyone. Any decision to proceed should be made in an in-person consultation with a physician.
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