Rumour: “Filler moves around the face and migrates elsewhere” — What does the science say?

Short answer: partly true. Filler shifting from the point where it was injected into a nearby area is a real phenomenon, and it is noticed mostly in the lips and around the eyes. How often it happens is not known. On the other hand, some of the appearances taken for migration are related to too much product, superficial or inappropriate placement, swelling or new treatments given before the previous filler has fully broken down. With hyaluronic acid fillers, the physician can dissolve misplaced product with an enzyme.

Where does the rumour come from?

On social media, images of a bulge appearing above the upper lip, bags under the eyes or a fullness that seems to have dropped below the cheekbone are often shared under the heading 'filler migration'. These images are real and show that the rumour is not entirely made up. What is exaggerated is the idea that filler travels freely around the face and will sooner or later migrate in everyone.

Is filler migration real?

Yes. Filler material passing from where it was injected to somewhere else is a phenomenon that health authorities list among the risks of filler and that is documented by cases in the medical literature. A review examining cases in which filler was detected outside the area where it was placed emphasises that migration does not have a single cause, that more than one mechanism may play a part and that the product can be found in the tissue even years later.

It is useful here to distinguish two situations. In most cases what is involved is the product spreading into a neighbouring area: filler in the lip shifting to just above the lip border, for example, or filler under the eye towards the upper part of the cheek. Filler appearing in an area far from the injection site, on the other hand, has been reported much more rarely and is associated more with fillers that do not dissolve. The problems of these fillers are dealt with separately in our article “Complications of Permanent and Semi-Permanent Fillers: Silicone, Granulomas, Late Reactions and Treatment”.

How common is it?

There is no reliable answer to this question. The information available rests mainly on individual case reports and small case series; there are no large studies that follow people who have had filler over a long period and measure the frequency of migration. Mild migration often goes unnoticed or unreported; on social media, meanwhile, because striking examples come to the fore, it may seem more common than it is.

There are also differences by area. In a study compiling the published problems related to lip filler, the most commonly reported problem was lumps, and migration was also listed among the problems associated with the lips. Migration, which in general is a rarely reported problem with filler, is noticed more often in the lips. The articles on our site “Filler Complications: Swelling, Nodules, the Tyndall Effect, Late Reactions and Dissolving Filler” and “Lip Filler Complications: Swelling, Lumps, Cold Sores, Filler Migration and Emergency Signs” are consistent with this picture: it is not possible to give a figure.

Is fullness above the lip always migration?

No. There is more than one possible explanation for a bulge above the upper lip that becomes more noticeable especially when smiling, and telling them apart requires an examination.

A recent study examining by ultrasound where filler lies in the lip supports this picture. It was observed that the layer beneath the skin of the lip is very thin, and that for this reason in most people the filler had been placed within the muscle layer rather than where intended; some injection techniques were reported to be associated with findings of migration. In other words, keeping the product exactly in the desired layer in the lip is harder than is assumed.

Under the eyes, a similar confusion arises with swelling: bags that persist or are more noticeable in the mornings may have more to do with the product retaining water than with migration. This subject is described in our article “Under-Eye Filler Complications: The Tyndall Effect, Prolonged Swelling, Visible Filler, Risk to Vision”.

What have imaging studies shown?

It is known that the effect of hyaluronic acid fillers lessens over months. However, the effect lessening and the product disappearing from the tissue altogether may not be the same thing. In a study in which 33 people who had had hyaluronic acid filler in the mid-face were examined by magnetic resonance imaging (MRI), filler was detected in the tissue in all participants even though at least two years had passed since the last treatment; in some people this period was found to be much longer.

This finding needs to be interpreted with restraint. The study is small, covers a single area, and some of the participants were imaged because of a complaint of swelling; in other words, it may not represent everyone who has filler. Nor does detecting product on imaging mean that a visible fullness persists in the face. Even so, these data point to an important possibility: there may still be product in an area where it is thought that 'my filler has dissolved', and new treatments placed on top of it may over time contribute to build-up, and build-up to the appearance of spilling over or migration.

For this reason, the frequency and amount of repeat treatments should be planned according to the findings of an examination, not according to the calendar. How long the effect of hyaluronic acid filler lasts varies with the product, the area and the person; for details, see our article “Hyaluronic Acid Filler: What It Is, How It Is Done and What the Risks Are”.

When should you see a physician?

Suspected migration is usually not an emergency; however, it needs to be assessed by a physician, because the approach differs for conditions that look similar, such as swelling, lumps, an inflammatory nodule or infection.

• A new fullness, bulge or soft palpable lump appearing outside the area where filler was placed
• Swelling that continues after the first weeks or appears later
• Blurring of the lip border, or a band-like bulge above the upper lip
• Hardness, redness, tenderness or increased warmth in the area (may be inflammation or infection)
• Unexplained swelling in an area where filler was placed months or years ago; in this case be sure to mention your history of filler

These symptoms may be a sign of vascular occlusion or a severe allergy. Details are given in our article “After Fillers: When Is It an Emergency? Vascular Occlusion and Other Warning Signs”.

What can be done about filler that has moved?

The physician first assesses by examination whether the problem really is related to the product and which filler was used previously; if necessary, an imaging method such as ultrasound may be used. In mild cases that cause no discomfort, monitoring alone is also an option.

With hyaluronic acid fillers, the physician may suggest dissolving misplaced or excess product with an enzyme called hyaluronidase. This enzyme dissolves hyaluronic acid only; it does not work on fillers that do not dissolve. The enzyme also has side effects such as swelling, redness and, rarely, allergy; for this reason the treatment should be carried out after an examination, by a physician and in a healthcare facility. If filler is being considered again after dissolving, your physician decides on the timing.

• Do not massage the area firmly on your own; do not try to 'push the product back into place'.
• Do not use dissolving products sold online.
• Do not have more filler placed on top to correct the appearance; the cause needs to be understood first.
• Keep your records showing which product was used, when and how much, and take them to your physician.

What can be done to reduce the risk?

• Ask for a measured, staged plan rather than a large amount in a single session.
• Ask for the area to be assessed by examination before a new treatment is placed on top of your previous filler.
• Tell your physician about all the fillers you have had before, their type and the dates.
• Follow your physician’s advice about not pressing on or massaging the area in the first days after the procedure.
• Have the treatment done only by a physician, in a healthcare facility and with a product of known origin.

These precautions may help to reduce the risk, but they do not remove it; migration can occur even after careful treatment.

Conclusion

Filler moving is a real phenomenon, but one whose frequency is not known, and it mostly takes the form of spread into a neighbouring area. Some of the appearances taken for migration, however, are related to too large an amount, inappropriate placement, swelling or layered treatments. Imaging studies suggest that in some people hyaluronic acid filler can remain in the tissue for longer than expected; this shows the importance of planning repeat treatments with restraint. When in doubt, see your physician without doing anything on your own.