What is dissolving filler and how does hyaluronidase work?
Dissolving filler means breaking down hyaluronic acid filler in the treated area with an enzyme called hyaluronidase. Hyaluronidase cuts the hyaluronic acid chains that hold the filler gel together, so the gel breaks apart and the volume reduces. The enzyme is injected into or just around the filler with a fine needle, and it starts working quickly.
Hyaluronidase also occurs naturally in the body, where it plays a part in the continual turnover of hyaluronic acid in the tissues. The body’s own enzymes also break filler down over months; when filler is dissolved, enzyme given from outside makes this happen within days. The hyaluronic acid in filler products is stabilised by cross-linking so that it lasts longer in the tissue, and hyaluronidase gradually breaks this structure down. Medical hyaluronidase products may be animal-derived or made in a laboratory based on the human enzyme, known as recombinant. The source of the product can also be considered when assessing allergy risk.
Beyond dissolving filler, hyaluronidase is used in medicine for other purposes too, for example to help some medicines and fluids given under the skin spread more easily. When dissolving filler, the aim is to remove or reduce unwanted filler. In aesthetic dissolving, the enzyme is dosed according to the layer and the amount of filler. The enzyme works most clearly on filler close to where it is injected, so locating the filler accurately directly affects the result. Hyaluronidase acts in the tissue for only a short time, so it is not expected to stay active for weeks after treatment. As with any medical product, you are entitled to ask the name and source of the hyaluronidase product before treatment.
When is dissolving filler needed?
Dissolving filler is most often planned for filler that looks unwanted or excessive, filler that has moved beyond the lip border or shifted, lumps that can be felt and a bluish tint under the eyes. When vascular occlusion is suspected, hyaluronidase is a core part of emergency treatment and is given without delay.
The most common reason for planned dissolving is aesthetic dissatisfaction. Filler built up in the lips over years of repeated treatments can migrate above the upper lip border and create a visible ridge. Filler placed too superficially under the eyes can show through thin skin as a bluish tint, or hold fluid and cause prolonged swelling. In the nose, filler that spreads over time can widen the bridge. Asymmetry, more volume than expected or a result out of keeping with facial proportions are other reasons. The filler is then dissolved, the area reassessed and a new plan made if needed. Before surgery such as a rhinoplasty, the surgeon may also ask for filler to be dissolved.
The emergency use of dissolving filler relates to vascular occlusion. Filler entering or pressing on a blood vessel can disrupt the tissue’s blood supply; blanching of the skin, a mottled purple discolouration and pain out of proportion to the treatment are among the early signs. Hyaluronidase is then usually given in high doses, repeated if needed, while blood flow to the area is closely monitored. Any change in vision needs urgent assessment without delay. Hyaluronidase can also be part of treating some delayed inflammatory reactions and persistent lumps; if infection is suspected, it is usually treated first. If you notice any of these signs after treatment, contact the doctor who treated you straight away.
Which fillers can be dissolved and which cannot?
Hyaluronidase dissolves only hyaluronic acid fillers. Products with different contents, such as calcium hydroxylapatite (CaHA), poly-L-lactic acid (PLLA), polycaprolactone, PMMA, silicone and polyacrylamide, cannot be dissolved with this enzyme. In hybrid products containing both hyaluronic acid and CaHA, the enzyme dissolves only the hyaluronic acid component, which is why knowing what your filler contains matters.
Being dissolvable with hyaluronidase is an important safety feature that sets hyaluronic acid fillers apart from other classes of filler. CaHA and PLLA products used as biostimulators cannot be reversed with this enzyme; their effect fades over time, and any problem is managed in other ways. Silicone, PMMA and polyacrylamide, which the body does not break down or which remain for a very long time, do not respond to the enzyme either. Hardening, lumps or late reactions with these products can need a more complex assessment, sometimes including surgery. This difference is also considered when choosing products for sensitive areas such as the lips and under the eyes.
Hyaluronic acid fillers do not all respond to the enzyme in the same way either. Denser, more highly cross-linked products may need more enzyme, or more than one treatment, than more fluid products. Whether the filler sits deep in the tissue or near the surface, and how long it has been there, also affect how much enzyme is used and where. If the same face has been treated at different times with different products, each area is assessed separately. Bringing records of which product was used, when and in what amount to your consultation therefore makes planning easier and helps avoid unnecessary use of the enzyme.
How is filler dissolved?
First you are asked when the filler was done, with which product and how much, your allergy history is reviewed and the area is examined. The skin is then cleansed and hyaluronidase is injected with a fine needle where the filler sits. Planned treatments are usually short and followed by a brief observation period for allergic reactions.
At consultation, the doctor assesses whether your concern is caused by filler, swelling or something else; not every unwanted appearance needs dissolving. Because hyaluronidase is an enzyme medicine, you will be asked in particular about previous allergic reactions to insect stings and medicines. Pregnancy and breastfeeding, an active infection in the area and your medication can also affect the timing of planned dissolving. The position and amount of filler can be assessed by examination and, where necessary, imaging such as ultrasound. If new filler is being considered afterwards, this is discussed from the outset and expectations are clarified. Photographs may also be taken for your medical record to compare the result later.
During treatment, the skin is cleansed with antiseptic and hyaluronidase is given where the filler sits, usually in a few fine-needle injections. Sometimes the area is gently massaged to help the enzyme spread through the filler. Planned dissolving usually starts with low doses and progresses as the result becomes visible; emergencies may need higher doses and repeated treatments. How long it takes depends on the area and the amount of filler. Afterwards, you are observed briefly for signs of an allergic reaction and given area-specific aftercare advice. The name and amount of product used are recorded for future plans. In emergencies, these steps are completed quickly so that treatment is not delayed.
What should I expect after dissolving filler?
Swelling, redness, tenderness and sometimes bruising may last from a few hours to a few days after treatment. Softening of the filler and a reduction in volume are often noticed within the first 24–48 hours. The final result is usually assessed after about two weeks, and a second treatment is planned if needed.
In the first hours after hyaluronidase, the area may look more swollen because of the injected fluid and the tissue’s response; this usually settles quickly. Any bruising usually fades within a week, and cold compresses can be soothing. Avoiding strenuous exercise, saunas and activities that press on the area on the first day, and not massaging the area unless your doctor advises it, are usually recommended. Most people return to daily life the same day or the next day. Itching, spreading redness or marked, increasing swelling may suggest an allergic reaction and should be reported to your doctor straight away. With difficulty breathing, or swelling of the face or lips that increases rapidly, seek emergency help.
How much of the filler has dissolved becomes clear within a few days, but because some swelling remains, assessment of the final result usually waits around two weeks. With large, dense or long-standing filler, a second treatment may be needed. Small irregularities left where filler was dissolved are also assessed during this period. Comparing the result with medical record photographs taken before treatment allows the change to be seen more objectively. At the follow-up, the result is reviewed together, and whether new treatment is needed, and if so with what approach, is discussed. Not rushing during this period helps identify more accurately what the area really needs.
What are the risks and limits of dissolving filler?
Common effects are swelling, redness, tenderness and bruising. An allergic reaction to hyaluronidase is uncommon; it usually takes the form of local swelling and itching, and very rarely it can be serious. Dissolving filler does not always restore the elasticity of tissue stretched by excess filler, and it has no effect on fillers other than hyaluronic acid.
Hyaluronidase can spread somewhat beyond where it is injected, so dissolving can be uneven or more filler than planned can be dissolved. Allergic reactions usually appear soon after treatment, but rarely they can occur hours later, so it is important to watch for symptoms during the first day. If you have had an allergic reaction to hyaluronidase, this should be added to your records for all future treatments. Infection is a rare risk, reduced by sterile conditions, proper skin preparation and advice not to touch the area afterwards. Swelling and bruising may be more noticeable after high-dose emergency treatment. If you notice an unexpected symptom, contact your doctor without delay.
The limits of dissolving filler should also be clearly understood. Lip or under-eye tissue stretched by excess filler for years may look loose or deflated for a while after dissolving, and this does not always resolve completely. Hyaluronidase does not correct age-related volume loss, sagging or changes in skin quality; it only reduces existing hyaluronic acid filler. Problems with CaHA, PLLA and other products of different content are managed in other ways. The decision to dissolve therefore considers the overall condition of the tissue, not only how the filler looks. Dissolving filler is often a starting point; whether new treatment follows depends on the condition of the area and your expectations.
Frequently asked questions
Does dissolving filler hurt?
Dissolving filler usually causes mild, brief discomfort: a short sting during the injection, sometimes followed by burning or stinging for a few minutes. In sensitive areas such as the lips, cold compresses or a numbing cream can reduce discomfort. Tenderness after dissolving filler usually eases considerably the same day.
How does the body get rid of dissolved filler?
Hyaluronidase breaks the hyaluronic acid in filler into small fragments, which are absorbed and broken down through the body’s natural pathways, largely via the lymphatic system. Because hyaluronic acid is a molecule already found in the body, dissolved filler is not expected to collect anywhere else. This happens on its own, and no further procedure is needed to remove the filler.
Will my lips or under-eyes look more hollow than before after dissolving?
In some people, the area can look slightly flatter or more hollow in the first days after dissolving than it did before the filler was done. Reasons include hyaluronidase temporarily reducing the natural hyaluronic acid in the tissue, and tissue stretched by filler taking time to recover. Natural hyaluronic acid usually replenishes quickly, so wait at least two weeks before judging the result.
I am allergic to bee stings. Can I have filler dissolved?
Dissolving filler may still be possible if you are allergic to bee or wasp stings, but you must mention the allergy beforehand. Bee venom also contains hyaluronidase, and a higher chance of reacting to the enzyme has been reported in people with this allergy. The doctor may consider a skin test, longer observation or another approach; in an emergency, benefits and risks are weighed separately.
How soon can I have filler again after dissolving?
After dissolving filler, waiting around two weeks before new filler is common. This allows swelling to settle, the effect of hyaluronidase to wear off completely and the true condition of the area to be seen. If the filler was dissolved because it had migrated or formed lumps, a different product, a smaller amount or a different technique may be discussed for the new plan.
Can filler done elsewhere, with unknown content, be dissolved?
Filler of unknown content can be dissolved with hyaluronidase only if it is hyaluronic acid, so the first step is to request the product name and treatment date from where it was done. Without records, an examination, with ultrasound where needed, can give an indication; some doctors try a low dose and watch the response. A lack of the expected response suggests a different content.
Is it possible to dissolve only the excess rather than all of the filler?
Yes, giving a low dose of hyaluronidase only at the points that look excessive or uneven can aim to reduce part of the filler. However, because it is not possible to fully control how the enzyme spreads in the tissue, more may dissolve than expected. Partial dissolving therefore starts with small doses, followed by a second treatment if needed once the result is visible.
Can I wait for filler to go on its own instead of dissolving it?
For mild dissatisfaction, waiting for hyaluronic acid filler to break down naturally is an option, though it can take months depending on the area. Migrated or lumpy filler, or filler showing a bluish tint under the eyes, may last longer than expected. Signs of possible vascular occlusion, such as blanching, mottled skin or increasing pain, mean contacting your doctor or an emergency department straight away.
Sources (3)
- Kroumpouzos G, Treacy P (JMIR Dermatology): Hyaluronidase for Dermal Filler Complications: Review of Applications and Dosage Recommendations (2024)
- Global Aesthetics Consensus Group (Plastic and Reconstructive Surgery): Global Aesthetics Consensus: Avoidance and Management of Complications from Hyaluronic Acid Fillers—Evidence- and Opinion-Based Review and Consensus Recommendations (2016)
- Birben AÖ, Kutlubay Z, Engin B, Serdaroğlu S (Dermatoz): Dermatolojide Dolgu Uygulamaları ve Komplikasyonları (2020)
This content is for general information and does not replace a personal medical assessment.