Juvelook (PDLLA): how far has it actually been established?

The PDLLA in the name refers to polylactic acid — a polymer of lactic acid — with its two isomers, the D form and the L form, mixed 50:50. These fine spherical particles are suspended in hyaluronic acid and injected.

The intended use published by the manufacturer reads: “injection of polylactide and hyaluronic acid into the subcutis to temporarily improve facial wrinkles in adults through physical restoration”. The wording is stiff, but the words to notice are temporarily and physical restoration. The approved wording is written around physically taking up space, not around making collagen.

In the body, two things actually happen, and they happen at different times. The hyaluronic acid occupies space from the moment it goes in and then disappears over some months, while the PDLLA particles stay and stimulate fibroblasts. So the change you see just after treatment and the change you see some months later have different causes. That structure is worth knowing about — around two to three weeks in, it is possible to feel that things look worse than they did at the start, and that is the stretch where the hyaluronic acid is leaving, not a failure.

Our reference library sorts boosters into five branches by material. Setting PDLLA alongside them gives this.

By purpose it sits in the same column as liquid PCL and CaHA. All three are on the side of “make my own collagen”, and what separates them is what the material is, what shape the particles take, and how long they stay. Which is why a line like “with Juvelook you do not need anything else” does not hold up. A face that needs filling needs something that fills; skin that has thinned needs something that stimulates; and only within that does choosing the material become the question.

This is the question we are asked most. Both are lactic acid polymers and so belong to the same broad branch, but the isomer composition and the look of the particles differ.

That much is fact. The explanation usually attached next — that particles which are smaller and smoother strike the body as less foreign, so the foreign-body response is smaller — is an inference drawn from the properties of the material, not the result of a trial that put the two products side by side in people. We could not find any such comparative study.

So nobody is in a position to answer “which of the two is better” at present. What can be answered goes as far as “what is different, and how”.

Searching under the product name turns up not very much.

The most substantial item is a study of the tear trough. Juvelook was injected in Korean women and assessed at 1 week, 1 month and 6 months; improvement and satisfaction were good and no serious complication occurred, the paper reports. There are things to hold alongside it when reading, though — the abstract does not state how many people took part, there is no comparison group, and follow-up runs to 6 months. The author list also mixes private practitioners, in Korea and abroad, with a training institute for the procedure.

Beyond that, what we could confirm amounts to a case report observing tissue change on ultrasound. A case report is a record that “this happened”; it is not the kind of material used as evidence of effect.

We could not find a randomised controlled trial. That is common with a product this new, and is not in itself a mark against it. But if you have been told something is “clinically proven”, it is worth asking what exactly that phrase refers to.

A nodule case has also been published for the same product. A 42-year-old woman was given Juvelook under the eye and three weeks later developed a firm but non-inflamed nodule; the report sets out how it was treated with a radiofrequency device.

Two things are worth marking here.

First, the authors of the paper reporting the effect and the paper reporting the nodule overlap. How to read that is this — the same group published both the good result and the problem, and the right reading is as a sign that nothing was hidden.

Second, nodules are not a new story in the collagen-stimulating family. We have written the same item into our Radiesse and DCLASSY references. And they are reported particularly in places like under the eye, where the skin is thin and the muscle covering it is thin too. The site changes the risk.

There is one more difference that matters. There is no drug that dissolves PDLLA. Of the products we hold, only the cross-linked hyaluronic acid, BYRYZN, can be reversed with hyaluronidase; the rest — liquid PCL, CaHA and PDLLA — have nothing that reverses them. So you should start knowing that this is a family where “if it looks wrong we can just dissolve it” does not apply.

The manufacturer's website carries a number along the lines of 52025-I10-32-3606. That number is a mark that the medical advertising passed pre-review; it is not a product licence number. A number with several hyphens running past ten digits is, as a rule, an advertising-review number. A product licence number is shorter than that and begins with one of the Korean device prefixes (romanised, jeoheo or jesu). We went through this distinction in detail in “Is this product approved by the MFDS?”.

To put it plainly: we could not confirm Juvelook's product licence number. The manufacturer has not written it into its public material, and we did not find it within the range we searched. What we could confirm is that it is distributed in Korea classified as a medical device under ‘tissue restoration material’, and no further.

We could not confirm US FDA approval either. The overseas sales pages we looked at listed the European CE mark and the Korean MFDS, and nothing else. If you have seen the phrase “FDA approved”, it is worth checking what it is approval for.

How long it lasts. The figure of 12 to 18 months circulates widely online. We could not trace where that figure comes from. Follow-up in the study above runs to 6 months. This is exactly why, in our piece on sessions and duration, we write a number of months for some products and leave it blank for others — where there is no basis, we do not write one.

How many sessions are needed. We could not find a standard protocol in the public material.

Whether it can be combined with other treatments. We could not find a study looking at it alongside another booster or a radiofrequency device. This is not particular to Juvelook: the data on combination as a whole are thin.

If somewhere answers all three of these with confidence, it is worth asking where those answers come from.

Juvelook is a product with an uncommon combination for a skin booster — PDLLA microspheres plus hyaluronic acid. That the filling part early on and the stimulating part later are split between two components is its structural feature.

At the same time, the published human data are still thin, a nodule under the eye has been reported, and it belongs to the family with no reversal agent. That is not to say a new product is a bad one; it is to say that this is where the line falls, at this point, between what can and cannot be said.

We take the view that what your face needs now matters more than how new a product is. A face that needs filling and a face that has thinned are different, and only once that is sorted does choosing the material become the question.

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.