In short
- Symptoms can appear years after the injection. A long interval is the rule, not the exception.
- What the literature describes most are granulomatous reactions and skin problems, followed by infection.
- The typical local symptoms: hardening, nodules, pain on pressure, changes in colour, deformity and swelling that comes and goes.
- 🔑 These do not wait: fever, spreading redness, pain that keeps increasing, an open wound or discharge. That is medical attention, not “an appointment in a month’s time”.
- The material can produce symptoms far from where it was injected, because it migrates.
- There is a disputed area of general symptoms — fatigue, joint pain — that has been proposed as associated with implanted materials. It deserves to be taken seriously and explained honestly, neither sold nor dismissed.
- Not everything is down to the biopolymers. A new symptom deserves a diagnosis, not an automatic attribution.
What most bewilders people about biopolymers is the timing. Someone has injections at thirty, goes a decade with nothing, and at forty-two starts to notice the area is hard, or gets swelling that comes and goes, and does not connect the two. That is understandable: nobody expects a problem to turn up ten years later.
This page explains what problems are described with these materials, why they can appear so late and — most importantly — which are raised at the next appointment and which do not wait.
It also explains something websites on this subject rarely say: that not everything happening to you is down to the biopolymers, and that attributing every symptom to them does not help you either.
The whole process is in the guide to biopolymer removal. To find out which test measures what you have, see imaging diagnosis.
What is described most
A scoping review published in 2024 gathered the world literature on industrial-grade liquid silicone injected for cosmetic purposes: 142 publications from 28 countries. Among the documented complications, the most frequent were:
| Complication described | Proportion of published cases |
|---|---|
| Granulomatous reaction | 41.5% |
| Dermatological problems | 41.5% |
| Infection | 35.9% |
| Pulmonary complications | 34.5% |
⚠️ That table is worth reading carefully, because it is easy to misread. These are proportions within the published cases — that is, among people who had already had a problem serious enough to end up described in a medical journal. It does not mean a third of everyone who had injections will have a pulmonary complication. What the table says is what kind of problems appear when they do appear, and which ones weigh most.
How it shows up in the area
The usual course starts locally:
- Hardening. The area feels firm, different to the touch, sometimes like plaques.
- Nodules or lumps you can feel, well defined, which can appear long after the treatment.
- Pain or discomfort on pressure, or after sitting for a long time if the material is in the buttocks.
- Changes in the skin: a different colour, an irregular look, retraction, skin that is stuck down.
- Deformity or loss of volume, because the material moves with time and gravity.
- Intermittent swelling: flare-ups that come and go, sometimes coinciding with a minor infection or a viral illness.
That last pattern — flare-ups appearing with no apparent cause — is one of the most distressing, because from the outside it looks arbitrary.
Why it takes so long to show itself
Because the material does not go away. It stays among the tissues and the body maintains a low-grade foreign body reaction around it, for years. That reaction can stay silent for a long time and then activate.
In a case published in 2025, a patient with biopolymers in the buttocks and face injected twenty years earlier developed severe inflammatory lesions, and the biopsy showed foreign body granulomas with the characteristic “Swiss cheese” appearance. Twenty years of silence did not mean safety.
It is why the time elapsed, on its own, is no reassurance.
The signs that do not wait
This is why this page exists. Most of the above is assessed calmly. This is not:
- Fever, with or without chills.
- Redness spreading across the area, especially if it advances within hours.
- Pain that increases progressively.
- Intense heat in the area.
- An open wound, an ulcer or discharge through the skin.
- Marked general malaise, a feeling of being genuinely ill.
Any of those signs can indicate an infection over the material, and an infection over a foreign body does not resolve on its own or with patience. It gets treated.
Away from the treated area
The material migrates, and that is why symptoms are sometimes not where you would look for them. Injected silicone has been described reaching lymph nodes and distant sites: in a case published in 2025, material injected into the breast and buttocks had migrated to the labia majora through the inguinal ligaments. An association between gluteal biopolymers and aggressive synovitis of the hip has also been reported.
These are published cases, not what happens to most people. But they explain why, faced with symptoms that do not fit, we look beyond the treated area.
The disputed ground: general symptoms
There are patients who describe fatigue, joint pain, a low-grade temperature or a diffuse malaise, and who relate them to the material. The name ASIA syndrome has been proposed for this — an autoimmune or inflammatory picture induced by implanted substances.
The honest thing is to say three things at once:
- It is a proposed and debated entity, not a diagnosis established with universally accepted criteria.
- The literature specific to biopolymers is limited, and there is no clear consensus on managing it: the authors of the 2025 case report on severe complications in a patient with rheumatoid arthritis say so expressly.
- That does not make the symptoms imaginary. In that same case, the coexistence of an autoimmune disease worsened the inflammatory response, and the management that worked was multidisciplinary.
Put another way: you will not be sold an explanation science does not yet support, and you will not be told that what you feel does not exist.
What is probably NOT down to the biopolymers
This section exists because it does the reader a favour.
When someone finds out they are carrying a permanent material, it is natural to start attributing everything to it. And there is a real risk there: a new symptom attributed to the biopolymer is a symptom that does not get investigated. A pain, a lump somewhere else, persistent fatigue or an abnormal blood test deserve a diagnosis of their own before being hung on the material.
Biopolymers explain a good deal. They do not explain everything, and confusing the two can delay the diagnosis of something else.
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
I had them years ago and I do not notice anything. Am I all right?
Having no symptoms is good news, but it is not the same as the material no longer being there. The absence of discomfort does not rule out a reaction around it, which is why the time elapsed is not on its own a reassurance.
Are the symptoms going to get worse?
There is no single course. Some people live with them for years without problems and others develop complications. What can be said is that the material is not reabsorbed, so the underlying situation does not improve on its own.
The area is hard but it does not hurt — is it urgent?
It is not urgent, but it does deserve assessment. Hardening indicates a reaction in the tissue around the material, and it is worth knowing how much is there and in what state before symptoms appear.
I get swelling every few months and then it goes — is that normal?
It is a described pattern and it is worth having assessed, rather than waiting for one flare-up to be worse than the last. If a flare-up comes with fever, advancing redness or discharge, you do not wait.
Can they cause symptoms elsewhere in the body?
Yes. Migration of the material at a distance and involvement of lymph nodes are described. That is why, faced with symptoms that do not fit the treated area, we examine beyond it.
Can this cause an autoimmune disease?
It is disputed ground. An association has been proposed, the specific literature is limited and there is no consensus on management. It is taken seriously, assessed with the right specialists, and nobody is sold a certainty that does not exist.
And if I have an infection?
An infection over an injected material does not resolve on its own. Fever, spreading redness, increasing pain or discharge are reasons to seek medical attention without waiting.
Do the symptoms go away if I have surgery?
They improve in a substantial proportion of cases, but the response is not complete in everyone. What can realistically be expected is in remove or monitor.
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 the world literature on illicit cosmetic injections: 142 publications from 28 countries; among the documented complications, granuloma (41.5%), dermatological problems (41.5%), infection (35.9%) and pulmonary complications (34.5%). https://pubmed.ncbi.nlm.nih.gov/39383418/
- Hormaza-Jaramillo A, Peñaloza Gonzalez D, Benavides-Ibarra SA, et al. Severe Complications Due to Biopolymers in a Patient With Autoimmune Disease: A Case Report and Review of the Literature. Aesthet Surg J Open Forum. 2025;7. A proposed association with autoimmune/autoinflammatory syndrome induced by adjuvants (ASIA), with limited literature and no clear consensus on management; a 58-year-old patient with material applied 20 years earlier and rheumatoid arthritis, with severe inflammatory lesions, MRI showing severe inflammation and a biopsy consistent with “Swiss cheese” foreign body granulomas; a good response to multidisciplinary management. https://pubmed.ncbi.nlm.nih.gov/40979311/
- Huo B, Tso R, Shen L, Mansberg R. Confounding diagnosis of metastatic disease on FDG PET/CT due to cosmetic liquid silicone administration in breasts and gluteal regions with silicone migration to labia majora. Radiol Case Rep. 2025. Cosmetic injections of liquid silicone can produce inflammation, chronic mastitis, distant migration and lymphadenitis; in the case described, migration through the inguinal ligaments as far as the labia majora. https://pubmed.ncbi.nlm.nih.gov/40895000/
- Llinás A, Bonilla G, Barrios V, Sadlik G, Gómez-Ortega V. Gluteal biopolymers and aggressive synovitis of the hip joint: A new reported association. J Plast Reconstr Aesthet Surg. 2022;75(2). Reports the association between gluteal biopolymers and aggressive synovitis of the hip joint. https://pubmed.ncbi.nlm.nih.gov/34844884/
Book your consultation
If you notice the area has hardened, you are getting lumps or you have flare-ups of swelling that come and go, you do not need to know what you were injected with to ask for an assessment: we examine you, decide which test adds anything and explain to you what is there.
And if fever, spreading redness, increasing pain or discharge appear, that does not wait for an appointment.
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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.
