GOURI and Sculptra — what actually differs

The most important row in this table is “published human data”. The other rows may be matters of design or preference, but that row decides what we are entitled to claim we know. We can say “two years” about Sculptra because a trial watched for two years; we stop at six months for GOURI because nothing has been published that watched any longer.

Sculptra is particles. Poly-L-lactic acid particles have a mean size of 52 µm (40–63 µm) and are plate-shaped and non-porous. They arrive as a freeze-dried powder and must be reconstituted with sterile water before treatment. That preparation step has been central to the safety discussion around this product for years, because how much it is diluted and how long it is left to hydrate have long been discussed in connection with nodule formation.

GOURI has no particles. The manufacturer patent describes a block copolymer of polycaprolactone and methoxy polyethylene glycol, colloidally dispersed in water, with a copolymer concentration of 25% by weight in the worked example (the consumer page states “21% PCL”, a different number). There is no reconstitution step, and the development paper argues that an uneven suspension is therefore not possible. The difference between liquid and microsphere polycaprolactone is set out separately in the same polycaprolactone, but liquid and microsphere are different things.

When the formulation differs, the data cannot be carried across. That is a principle this site repeats. Sculptra’s 25-month data cannot be moved onto GOURI, and the reverse is equally true. Being filed under the same name — “collagen stimulator” — does not mean sharing evidence.

This is the difference you would actually notice in the treatment room. Sculptra goes deep — the 2024 systematic review advises the supraperiosteal, subcutaneous and subdermal layers, and the approved indication itself refers to a deep dermal grid (cross-hatch) injection technique in the nasolabial fold. GOURI goes shallow — the design target is the dermis to the dermal–subcutaneous junction, and the published case series divided the face into 10 points (5 per side).

So the two are designed against slightly different problems. Something placed deep is designed to address lost volume; something spread shallow and wide is designed to address the thickness and texture of the skin itself. But no study has tested whether that design intent produces different outcomes in people. Design and result are separate claims.

Different planes also mean a different character of risk. The shallower the placement, the more the problem is palpable irregularity and superficial nodules; the deeper it goes, the more it becomes about clumping and a different profile of vascular risk. There is no basis for saying which is safer — because they have never been compared.

Do not read the right-hand column without its last row. There is more data on the Sculptra side, but the people who pooled and appraised that data wrote in their own words that the evidence is of low quality. “More” and “enough” are different words. That is also why this site recommends neither product over the other.

For liquid-form polycaprolactone, five peer-reviewed papers is the entirety of the literature — two in rats, one human pilot (30 people, 6 months), one case series (2 people, 3 months) and one case report (1 person). The course over time is set out in GOURI — from the day of the injection to months later.

Sculptra has numbers. In the trial supporting the 2009 aesthetic indication, papules were reported in 1.9% and nodules in 0.9% at 25 months (per the manufacturer statement), and these were typically palpable, asymptomatic and not visible. Older studies carry much higher figures — one study cited in the 2024 systematic review reported subcutaneous papules and nodules in 41% of those studied. That figure should not be read as a current rate. The older studies used smaller reconstitution volumes and different hydration times, and an inverse relationship has been reported between dilution volume and nodule formation. The 2023 revision of the Korean approval, which raised the reconstitution volume to 9 mL, can be read in the same light.

GOURI has no numbers. Within the range of our search, we found no case of a nodule or granuloma with liquid-form polycaprolactone. The two-person case series states explicitly that there were no palpable or visible lumps and no granulomas or nodules, and the rat study found no residual material or foreign-body reaction over 12 weeks.

But “no numbers” is not “0%”. GOURI is distributed in 45–55 countries, and the published human observation totals 33 people. In that situation, “no reports” is not evidence of rarity; it means there is no basis on which to calculate a rate. Sculptra’s 1.9% and 0.9%, by contrast, exist because someone counted. The side that has numbers looking riskier is a common illusion. Nodules in general are set out in nodules after treatment — how common, when they appear, and what is done.

Neither dissolves with hyaluronidase. Hyaluronidase is an enzyme that breaks down hyaluronic acid, and neither polycaprolactone nor poly-L-lactic acid is hyaluronic acid. The literature states of the polycaprolactone class that it does not respond to hyaluronidase and may require invasive removal. What dissolves and what does not is set out in hyaluronidase — what can be reversed and what cannot.

When something does go wrong, what the literature records is management rather than dissolution — intralesional steroid, ultrasound-guided treatment and, in some cases, surgical excision. For poly-L-lactic acid nodules there is a scoping review mapping a diagnostic and treatment pathway; for microsphere polycaprolactone nodules there are published ultrasound-guided cases. For liquid-form polycaprolactone there is no management literature at all — because there are no nodule cases.

Irreversibility is what the two products share, and it is the most practical thing they share. It is also the decisive break from cross-linked hyaluronic acid boosters. So for anyone starting in this class, we say plainly: do not decide on the assumption that it can be dissolved if you dislike it.

When you see “an FDA-approved product”, you are entitled to ask what it was approved for. Sculptra’s 2004 approval was for HIV-related facial lipoatrophy; the aesthetic approval came in 2009. Those are different indications. And a US approval tells you nothing about what is licensed in Korea. How to read a licence number is set out in a licence number and an advertising-review number are not the same thing and what one licence number tells you, and what it does not.

We could not obtain the Korean licence text for either product, because the MFDS database blocks automated lookup. The most reliable check is to read the licence number printed on the box — Article 20 of the Korean Medical Devices Act requires it to appear on the container or outer packaging.

We do not say “A is better than B”. With no comparative study, we cannot. What we can do is write down where the decision actually turns in consultation.

• Whether what bothers you is lost volume or thin skin. A deep-plane design and a shallow-plane design are aimed at different problems — though that distinction has not been verified in people.
• Whether you want the thicker file. If so, Sculptra has 25-month data. You should also know that a systematic review rated that data “of low quality”.
• Whether you are interested in trying something new. If so, the fact that liquid polycaprolactone rests on 33 people is the condition of that choice. Choosing it knowingly is different from choosing it unknowingly.
• Whether you want something reversible. If so, neither is the answer. You should be looking at cross-linked hyaluronic acid.

Different classes solve different problems. The five classes (cross-linked HA, PCL, PN, hADM, CaHA) are placed side by side in seven collagen boosters compared, and choosing from the symptom rather than the product is set out in collagen boosters — what differs between the classes.

What we most want to leave you with is not a ranking. It is that one product has a trial that watched for 25 months and the other has six months in total, and that even the 25-month file was appraised as “low quality” by the people who read it. Hold both sentences at once and, whichever you choose, your expectations will not outrun the size of the evidence.

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.