GOURI and Rejuran — What Differs, and What Has Not Yet Been Compared
“Which is better, GOURI or Rejuran?” is the comparison that comes up most often in consultation. So let us say it first — no study has compared the two directly in humans. This article sets their data side by side; it is not the result of a contest. Placed side by side, what separates them most is not the material but the gate each had to pass to reach approval.
The short answer
No study has compared GOURI (liquid-form polycaprolactone) and Rejuran (polynucleotide) directly in humans. So there is no data with which to answer “which is better.” Placed side by side, what separates them most is not the material but the gate each had to pass to reach approval. Rejuran is a medical device, so human clinical trial data was required for its approval, and it passed a phase 3 trial with 72 enrolled and 70 analysed (J Korean Med Sci 2014;29(Suppl 3):S201–S209, Seoul National University Bundang Hospital). For GOURI the published human data comes to 33 people in total with a longest follow-up of six months, and we could not find a single human biopsy study. But the scope of what the Rejuran trial demonstrated has to be read precisely too — the primary endpoint was an improvement rate on photographic assessment and the comparator was a hyaluronic acid product rather than placebo, so what it showed extends to “not inferior to a hyaluronic acid product.” Reversibility differs as well — GOURI does not dissolve with hyaluronidase, while Rejuran is degradable, so dissolving does not arise as a concept.
The comparison on one page
| Item | GOURI (liquid-form PCL) | Rejuran (PN) |
|---|---|---|
| Material | Aqueous polycaprolactone solution, no particles | Polynucleotide |
| Regulatory pathway | We could not verify the Korean approval text | Medical device — human trial data required for approval |
| Best human data | 30-person pilot at six months + 2-person case series + 1 case report = 33 people in total | Phase 3, 72 enrolled · 70 analysed (J Korean Med Sci 2014;29(Suppl 3):S201–S209) |
| Trial design | Single arm, no control group | Randomised, double-blinded, split-face, active-controlled |
| Result | “Significant improvement in skin quality and volume” (30 people, six months) | Photographic improvement rate 95.7% (67/70) versus 94.3% (66/70), difference 1.4 percentage points, meeting a non-inferiority margin of −15% |
| What the trial demonstrated | Without a control, as far as “it improved” | As far as “not inferior to a hyaluronic acid product” |
| Human biopsy | We could not find a single study | Histology was not a primary endpoint in that trial |
| Sessions | Manufacturer’s official FAQ: one by default, optionally 1–2 more at 4–6 week intervals | Trial protocol: three sessions at 2-week intervals, 12-week follow-up |
| Adverse events | At 33 people, an incidence cannot be calculated | In the trial, 31.9% versus 48.6% (p = 0.042) — fewer than the comparator |
| Can it be reversed | Does not dissolve with hyaluronidase | Degradable — not applicable |
| Treatment area | Manufacturer’s official FAQ recommends the face only; hands and neck are listed as data being collected | The trial was on the face |
The session counts come from different places
The row easiest to miss in that table is sessions. The two numbers are different in kind.
Rejuran’s “three sessions at 2-week intervals” is a number that came out of the phase 3 trial protocol. It means the product was trialled at that number of sessions and produced that result (an improvement rate of 95.7%).
GOURI’s session count came out of manufacturer guidance — the official FAQ states “one session is recommended, optionally 1–2 follow-up sessions at 4–6 week intervals.” No trial has compared outcomes by number of sessions in humans. For reference, the widely circulated “three sessions at 3–4 week intervals” is a figure for which we could not find a primary source, and it disagrees with the manufacturer’s official FAQ. That is set out separately in how many GOURI sessions, how far apart.
How to read the adverse-event numbers
In the Rejuran phase 3, adverse events were 31.9% versus 48.6% (p = 0.042) — fewer on the Rejuran side. What makes that number meaningful is that it has a denominator and a control group.
For GOURI we could not find a single nodule report. But with only 33 published human subjects, this is not evidence that nodules are rare — it means an incidence cannot be calculated. “There is no number” and “0%” are different things. The timing and management of nodules generally are set out in nodules after treatment.
So how do you choose
With no direct comparison, the choice is made not on superiority but on conditions. There are four axes we actually put in front of people in consultation.
| What you prioritise | Which way it leans | Why |
|---|---|---|
| Thickness of the data | Rejuran | Medical device phase 3, 70 analysed. But the scope demonstrated extends only to “not inferior to a HA product” |
| Room to reverse it | Rejuran | GOURI does not dissolve with hyaluronidase |
| Burden of repeat sessions | GOURI | One session by default versus three in the trial protocol |
| Areas with data | Both, the face | For GOURI the manufacturer classifies areas off the face as data being collected |
What the two products have in common is that they aim at the same problem — not volume but the density and texture of the dermis. If the change came from lost volume, neither is the answer. That distinction is written out in which skin is GOURI suited to.
Frequently asked questions
Can I have both?
They are sometimes combined, but the order and the interval matter. In particular, layering into an area that already contains irreversible material (PCL, PLLA, CaHA) makes it impossible to tell what caused a problem later. We could not find trial data on combining the two products.
If Rejuran passed a phase 3, isn’t it better verified?
The data is thicker on the Rejuran side. But passing a phase 3 does not mean “better than GOURI” — because no trial has compared the two directly. And what that phase 3 demonstrated was non-inferiority against a hyaluronic acid product, not against placebo.
Is it more natural because it comes from salmon DNA?
We are not aware of data showing that the origin of a material determines how natural the result looks. Rejuran’s evidence comes from its trial results, not from its origin.
What accounts for the price difference?
Price is set by product cost, number of sessions and treatment time together. But when the number of sessions differs, comparing totals is not the same as comparing the price of one session — the Rejuran trial protocol is three sessions.
Do both of them fill volume?
No. Both aim at the density and texture of the dermis rather than volume. GOURI is an aqueous solution and was not designed to fill volume immediately. If lost volume is the main concern, neither product is pointed the right way.
When does the change show?
For GOURI, the earliest change recorded in the literature is at 4 weeks (2 people), and the earliest confirmed collagen increase in tissue is at six weeks in animals. The Rejuran phase 3 was designed as three sessions at 2-week intervals with 12-week follow-up. Judgement timing in general is in when improvement shows, and when to judge it.
Who wrote this
Written and reviewed by Lee Chi-Hak, MD, medical director of Miso Clinic in Daegu, South Korea. Every study cited above is given together with its design, its size and the limitations the authors themselves recorded, and where we could not find data, we have said that we could not find any.
| Medical director | Lee Chi-Hak, MD |
|---|---|
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References
- J Korean Med Sci 2014;29(Suppl 3):S201–S209 — Rejuran (PN) phase 3, Seoul National University Bundang Hospital, 72 enrolled · 70 analysed, randomised, double-blinded, split-face, active-controlled, three sessions at 2-week intervals, 12-week follow-up, improvement 95.7% versus 94.3%, adverse events 31.9% versus 48.6% (p = 0.042).
- Ponzo M et al., PRS Global Open 2025;13(11), PMID 41210393 — GOURI, 30-person pilot, six-month follow-up.
- GOURI case series (2 people, 3 months, 10 points on the face, 31G needle) and case report (1 person) — human subjects total 33.
- GOURI manufacturer official FAQ — on sessions (“One session is recommended. Optionally, 1-2 follow-up sessions at 4-6 weeks interval.”) and on treatment area (“We recommend to use GOURI on the face only.”).
Everything in this column 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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