In short
- “Biopolymer” is a colloquial term, not a chemical one. It groups very different permanent materials under a single word.
- The three that come up again and again are industrial-grade liquid silicone, polyalkylimide and methacrylate (PMMA).
- 🔑 They are not all on the same footing. Industrial silicone injected for cosmetic purposes is outside any healthcare channel. PMMA, by contrast, is a filler material that is regulated and used by doctors in other countries, with a published consensus.
- What is decisive is not only the substance: it is what was injected, at what purity, in what area, in what plane and by whom.
- In the reviewed literature on industrial silicone, the most treated areas were the buttocks (35%) and the breast (13.3%), and the most affected population trans women (49.9%) and cis women (40.8%).
- The most common thing is not to know. Many patients were never given the name of the product, and some of what was injected were mixtures.
- If there is no paperwork, the way to get your bearings is examination and imaging, not memory.
Almost nobody comes into the consulting room saying “I was injected with polyalkylimide”. They come saying “I think I was given biopolymers”, often rightly, but without knowing exactly what that means.
It is worth starting with what almost no website says: “biopolymer” is neither a specific substance nor a chemical category. It is a word the language of aesthetic surgery has come to use as an umbrella for permanent filler materials, very different from one another, which the body does not reabsorb. Behind that single word are things that do not behave the same, do not look the same on a scan and do not have the same legal status.
This page sorts that out. Not to put a name to what you are carrying — that is rarely achieved from memory alone — but so that you know what is being looked for and why the answer matters.
This page develops the first question patients ask about biopolymer removal. If what you were given was hyaluronic acid, the situation is completely different and it is in hyaluronic acid treatments.
What is really behind the word
Industrial-grade liquid silicone
It is the classic scenario and the best documented. It is not the silicone of a breast implant — which is an implant with a shell, placed in theatre — but liquid silicone injected directly into the tissue, frequently of industrial rather than medical grade.
A scoping review published in 2024 brought together the world literature on its illicit cosmetic use: 142 publications from 28 countries. The profile it describes is very consistent: 49.9% of those affected were trans women and 40.8% cis women, and the most treated areas were the buttocks (35%) and the breast (13.3%).
It is the material most associated with the term “biopolymers” in Latin America and the one behind most enquiries.
Polyalkylimide
A permanent filler gel that was marketed as a medical device and was used above all for facial and body volume, including the correction of fat loss. Its problem is not illegality but permanence: because it is not reabsorbed, any late complication becomes a surgical problem.
Methacrylate (PMMA)
Here is the nuance almost the whole sector skips, and it is worth stating precisely: methacrylate is not the same as industrial silicone.
PMMA is used as a filler material by doctors and within a regulated framework in other countries. There is a Brazilian consensus published in 2018 that gathers the experience of 87,371 cases and sets out specific recommendations on concentration, contraindications by anatomical area and plane of injection. That is: it is not a clandestine substance, it is a material with indications, limits and rules of use.
What it does share with the others is what matters to you: it is permanent. And when it causes problems — granulomas, nodules, late inflammation — the management resembles that of a biopolymer more than that of a resorbable filler.
Mixtures, and the unknown
In clinical practice this is the most frequent category. An unlabelled product, repeated sessions with different materials, or simply substances nobody ever identified. It is not a lapse of memory on the patient’s part: in many cases the information was never given.
Why telling them apart matters
It might look like an argument about labels. It is not, for three practical reasons:
- It changes what shows on a scan. Each material has a characteristic appearance on ultrasound, and that is now a genuine route to identification. It is set out in the page on imaging diagnosis.
- It changes the outlook and the conversation. A medical device injected by a doctor with a described technique is not the same as an unknown volume of industrial material spread between planes.
- It changes how the surgery is planned. The quantity, the spread and the depth determine what can be removed and what cannot.
What does not change is the most important thing: none of these materials dissolves. Hyaluronidase, which does break down hyaluronic acid, has no effect on them at all, because they are chemically different. That confusion comes up in the consulting room constantly and is explained in the page on hyaluronidase.
How to try to find out what you were given
In order of real usefulness:
- Any piece of paper. An invoice, a consent form, a label, a message, the name of the product noted on your phone. It is the only thing that gives certainty.
- Where, when and who. The country, the year and the type of premises tell you a fair amount: a medical practice is not the same as someone’s home.
- How much and in how many sessions. The approximate volume completely changes the approach.
- What you notice and since when. The way problems appear is not identical for every material.
- Examination and imaging. When there is no paperwork — which is the usual case — this is the route. An ultrasound in trained hands can point to the type of material.
And one thing worth setting aside: not knowing what you were given is not your fault, and it does not prevent the case being assessed. We work with what there is.
Book an appointment
You can book your own appointment. Pick the day and time from the free slots in the diary, in a panel that opens right here, without leaving this page.
Frequently asked questions
Is “biopolymer” a medical term?
Not exactly. It is a term in common use that groups very different permanent filler materials. In the medical literature each substance is named for what it is: silicone, polyalkylimide, methacrylate.
Is the silicone in breast implants a biopolymer?
No. An implant is a device with a shell that is placed in theatre and can be removed as a unit. Injected liquid silicone infiltrates between the tissues and does not form a pocket that can be emptied. They are different situations.
Is methacrylate illegal?
Not everywhere. It is a filler material used by doctors within regulated frameworks in other countries, with a published consensus covering tens of thousands of cases. What it is, in any case, is permanent.
I was told it was “long-lasting hyaluronic acid”. Could it be a biopolymer?
It is a description worth clarifying, because hyaluronic acid is resorbable by definition. If the product is still there years later unchanged, what was actually injected needs looking into.
Can a blood test tell what it is?
No. The pointers come from examination and from imaging. And it is worth knowing before pinning hopes on theatre: the material removed at surgery is not routinely sent for analysis. There are laboratory techniques capable of identifying it, but they are not part of routine clinical care, and it is explained in the page on which test detects it.
I have no paperwork at all — is there any point in coming?
Yes. It is the commonest situation. You are assessed with an examination and whichever tests are appropriate, and the decision is taken from there.
Does the country where I had it done matter?
It helps to get your bearings, because the substances most used have not been the same everywhere or in every period. But it is a pointer, not a diagnosis.
Can I have filler again afterwards?
It is a reasonable question and the answer depends on the state of the area after removal. It is assessed case by case, and never on tissue that is still inflamed.
Sources
- Gerk A, Telles L, Carroll M, et al. Use of industrial liquid silicone: a scoping review. Acta Cir Bras. 2024;39. A scoping review of illicit cosmetic injections across six databases up to 2022: 142 publications from 28 countries; 49.9% trans women and 40.8% cis women; most treated areas the buttocks (35%) and the breast (13.3%); complications described: granuloma (41.5%), dermatological problems (41.5%), infection (35.9%) and pulmonary complications (34.5%). https://pubmed.ncbi.nlm.nih.gov/39383418/
- Blanco Souza TA, Colomé LM, Bender EA, Lemperle G. Brazilian Consensus Recommendation on the Use of Polymethylmethacrylate Filler in Facial and Corporal Aesthetics. Aesthetic Plast Surg. 2018;42(5). A consensus on the use of methacrylate as a facial and body filler material, based on an experience of 87,371 cases, with recommendations on concentration, contraindications by anatomical area and plane of injection. https://pubmed.ncbi.nlm.nih.gov/29872906/
- Tang Y, Wang Z, Bi M, Jia Y. Clinical Applications of High-Frequency Ultrasound in Filler Identification and Complication Management. Semin Ultrasound CT MR. 2026. Each filler material has distinct ultrasound features, which allows the injected product to be provisionally identified. https://pubmed.ncbi.nlm.nih.gov/42342087/
Book your consultation
If you suspect what you were injected with was a permanent material and do not know which, the assessment starts exactly there: by finding out what is there, where it is and how much. You do not need to bring a diagnosis or the name of the product.
At ICPM we also see people who had injections in another country or many years ago.
Clinical confirmation by the surgeon
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Last reviewed: 6 September 2026. This content is for information only and does not replace an individual assessment by a healthcare professional.
