What is the filler dissolving agent called Hyaluronidase (or 'Hyalase')

The increasing popularity of soft tissue dermal fillers in recent decades can be largely attributed to the advent of a product known as hyaluronidase or ‘hyalase’, which offers the possibility to reverse dermal filler treatment. For more information, read more at our Dermal Filler Guide.

On the one hand, having access to a dissolving agent is a reassuring factor for injectors, as it provides a solution in the case of emergencies or complications. However, it can also lead to injectors becoming somewhat overzealous, knowing that the filler can be easily dissolved if needed.

From a patient’s perspective, the term “dissolving” implies a sense of safety, where they believe that if the filler is overfilled or if they simply do not like the results, it can always be reversed. While this notion holds true to a certain extent, it is important to note that this reversibility comes with certain costs and consideration.

About Hyalase

Hyaluronidase (referred to more commonly as hyalase), is an enzyme that plays a crucial role in various biological processes and is commonly known for its ability to break down hyaluronic acid, a naturally occurring substance found in the body’s connective tissues and fluids. Hyalase works by depolymerising hyaluronic acid, which allows for increased tissue permeability and improved dispersion of injected substances.

Hyalase usage in cosmetic medicine

Due to its unique properties, hyalase finds extensive use in the field of medicine, particularly in cosmetic medicine. Most soft tissue fillers used in the cosmetic industry today are composed of hyaluronic acid (HA), earning them the name “temporary fillers” because they naturally degrade within a limited timeframe in the body.

Understanding this process is fascinating. With HA being a naturally occurring substance present in the body’s connective tissues and fluids, it plays a vital role in maintaining tissue integrity by stimulating collagen production. Nature has a way of balancing itself, and the HA produced by the body is also naturally metabolised once it has fulfilled its function. This breakdown is facilitated by an enzyme called hyaluronidase (or hyalase).

A remarkable aspect of scientific advancements in cosmetic medicine is that – not only has HA been synthesised for commercial use – but its antidote, hyaluronidase; has also been manufactured. This enables the controlled and reversible breakdown of HA dermal fillers when desired.

Hyalase used as a tool to mitigate certain complications

While HA-based filler treatments have gained popularity, it’s important to acknowledge the associated complications, which include but are not limited to vascular occlusion, infection, asymmetry, Tyndall effect, granuloma formation, biofilm, and dermal filler migration. In the event of such complications, a need to dissolve the filler may arise, and this is where hyalase proves invaluable.

One of the most critical, albeit rare, complications is vascular obstruction caused by the presence of HA-based gel fillers occupying space within the complex vasculature of the face. Even in the most skilled hands, there remains a slight risk of vascular compromise. When signs or symptoms of vascular obstruction emerge, immediate action is to be taken to dissolve the dermal filler and preserve the integrity of the affected tissue. This may involve multiple sessions of hyalase administration by the experienced and registered injector, combined with strict protocols and specific manoeuvres to address the situation effectively.

Hyalase to reverse an ‘overfilled’ look

In the realm of cosmetic medicine, one frequently encountered phenomenon with soft tissue dermal fillers is the occurrence of overfilled faces. This ‘overfilled’ look can arise due to multiple sessions of filler placement over time or the excessive use of filler during a single session, resulting in aesthetically displeasing outcomes. While the body’s own endogenous hyaluronidase will eventually break down the dermal filler naturally over time, the process can be expedited by introducing exogenous hyaluronidase. This external hyaluronidase enzymatically breaks down the HA molecules, causing them to lose their structural effect.

Another common undesirable effect of dermal fillers in cosmetic practice is filler migration, where the filler product moves from its original anatomical location to another. This migration can be influenced by factors such as the type of filler used, and sometimes inadequate technique employed in terms of the overall understanding of anatomical connections.

The migration of fillers can be distressing for patients and may require the use of hyalase, to dissolve the migrated filler, with the objective of achieving a desired aesthetic outcome.

Over-dissolving considerations when using Hyalase

The use of hyaluronidase or hyalase in emergency situations to dissolve dermal filler, to address untoward side effects, or to achieve a more aesthetically pleasing outcome is truly remarkable. However, when it comes to using the hyalase dissolving agent for addressing asymmetry or to selectively dissolve filler in a controlled manner, it heavily relies on the experience and expertise of the treating injector. The reason for this is that hyaluronidase has a strong affinity for hyaluronic acid, and as such, hyalase tends to dissolve more than what is specifically required. This is a crucial aspect to understand, as hyalase may necessitate careful dosing and multiple treatment sessions to achieve the desired outcome without over-dissolving the filler.

A ‘phased’ approach to using Hyalase

Another interesting factor to consider is the extended half-life of the dissolving agent once it is injected, which can last several days, sometimes up to five days. This duration is beyond the control of the injector, and; as touched on in the section directly above, over-use of hyalase may result in unintended over-dissolution of the filler. In such cases, refilling may be necessary. Therefore, it is important to note that, when dealing with aesthetic correction of filler using hyalase, it is generally advisable to err on the side of under-treatment initially – and then review the results after one week to assess the need for further dissolving or adjustments. This approach ensures a more controlled and precise outcome.

Potential side effects with Hyalase

As with any other medical treatment, the use of hyalase comes with a specific side effect profile. The percentage of allergic reactions to hyaluronidase is relatively low. However, while allergic reactions to hyaluronidase are rare, they can still occur.

According to clinical studies and other research, the incidence of allergic reactions to hyaluronidase is estimated to be less than 1%. It is important to note that individual susceptibility to allergies can vary, and some individuals may have a higher risk of developing an allergic reaction.

Adverse reactions to hyaluronidase can range from mild localised reactions, such as redness and swelling, to more severe systemic allergic reactions.

The Cosmetic Doctors at Pavilion Cosmetic Medicine carefully evaluate the patient’s medical history, perform proper testing when necessary, and monitor for any signs of allergic reactions during and after the administration of hyaluronidase. Our Cosmetic Doctors may perform preliminary skin testing to establish any allergy to hyaluronidase.

Notably, special caution should be used in patients with a history of bee sting allergy, because hyaluronidase is one of the many biologically active components in bee venom. In the presence of infection, hyaluronidase can spread infection and should only be used in conjunction with systemic anti-biotics.

Sensitivity testing for Hyalase allergic reactions

Cosmetic Doctors at PCM may conduct a preliminary skin test using a micro dose of Hyaluronidase. This photo is an example of a positive test result.
Your Questions Answered

Frequently Asked Questions (FAQs)

Can non-hyaluronic acid-based fillers like biostimulators be dissolved with hyaluronidase as well?

No, hyaluronidase is specifically designed to dissolve hyaluronic acid-based fillers and does not have the same effect on non-hyaluronic acid fillers such as biostimulators.

How many sessions of hyalase are usually needed to completely dissolve filler for aesthetic reasons?

The number of sessions required to dissolve filler completely for aesthetic reasons can vary depending on factors such as the type of hyaluronic acid filler used, the anatomical location, and the duration since the filler was injected. In most cases, 2-3 sessions spaced apart at one-week intervals are typically needed to achieve the desired result.

Can the filler be dissolved partially using hyalase?

Indeed, soft tissue fillers can be partially dissolved using hyaluronidase (also known as ‘hyalase’), allowing for targeted treatment of small areas or minimal volumes. However, it’s important to consider that hyaluronidase has a relatively long half-life, extending over several days. As a result, the outcome of the dissolution process can only be accurately assessed after a few days when the effects of hyaluronidase have subsided.

It can be challenging to determine the ultimate result immediately after the treatment, and it is generally recommended to evaluate the outcome around day 5-7 to make a comprehensive assessment of the dissolved area. This timeframe allows for the resolution of any temporary effects caused by hyaluronidase and provides a clearer picture of the treated area.

Regular follow-up and assessment by our Cosmetic Doctors at Pavilion Cosmetic Medicine is crucial for monitoring the progress and adjusting any further treatment if necessary.

Can hyaluronidase treatment dissolve natural collagen as well?

No, hyaluronidase is specifically designed to dissolve hyaluronic acid and does not directly dissolve natural collagen. However, over-dissolving of hyaluronic acid with hyaluronidase can give a depleted or over-dissolved appearance, affecting the overall aesthetic outcome. This is because hyaluronic acid is naturally present in the soft tissue required for collagen synthesis.

Is the natural hyaluronic acid replenished after being dissolved by hyaluronidase?

Yes, the body can regenerate natural hyaluronic acid over time. The replenishment of natural hyaluronic acid is a natural process, aided by the production of collagen and the presence of hyaluronic acid. However, the rate of replenishment can vary depending on factors such as age, lifestyle, and overall health. It may take months or even years for the natural hyaluronic acid levels to fully recover.

How long should one wait before reinjecting a soft tissue filler in an area that has been treated with hyaluronidase?

As a general guideline, it is recommended to wait approximately 5-7 days before reinjecting a soft tissue filler in an area that has been treated with hyaluronidase. This allows for the appropriate time for the effects of hyaluronidase to subside and for the tissues to stabilize before considering further filler injections. The timing may also depend on the individual patient and their specific situation, so it’s best to consult with a qualified healthcare professional for personalised advice.

How will I know if I am allergic to Hyaluronidase?

At Pavilion Cosmetic Medicine, our Cosmetic Doctors take a proactive approach to minimise complications, and one of the steps we take is conducting a preliminary skin test using a micro dose of Hyaluronidase.

During this test, an intradermal injection of approximately 3 units is administered. If a wheal appears within 5 minutes and persists for 20-30 minutes, accompanied by localised itching, which indicates a positive allergy test.

It is important to note that while a positive skin test suggests a potential allergy, it does not completely exclude the possibility of an allergic reaction. Allergic reactions can vary in individuals, and additional precautions and monitoring are still necessary during the administration of Hyaluronidase or other related procedures. Our aim is to prioritise patient safety and ensure the best possible outcomes.


If I have been injected with hyaluronidase in the past with no adverse events, am I still susceptible to having an allergic reaction?

While a previous injection of hyaluronidase without any adverse events is a positive indication, it does not guarantee that you are completely immune to future allergic reactions.

Allergies can develop or change over time, and individual responses to substances can vary. It is possible to develop an allergic reaction to hyaluronidase even if you have had previous exposure without any issues. Therefore, it is important to inform your healthcare provider about your medical history, including any previous reactions or allergies, so that they can make an informed decision and take necessary precautions during any future treatments involving hyaluronidase.

Is the Hyalase treatment painful?

The hyaluronidase has a stinging effect when injected under the skin. This is minimised by the addition of an aesthetic agent. Also, there is the possibility of topical application of numbing agent that further minimises the discomfort. Post treatment swelling along with minor bruising is common and usually subsides within 3-5 days.

How much does the Hyalase dissolving treatment cost?

The cost of hyaluronidase treatment for soft tissue fillers performed by another clinic other than Pavilion Cosmetic Medicine starts at $550 including GST.

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We welcome you to Pavilion Cosmetic Medicine Sydney for a consultation with our cosmetic doctor, who'll assess and tailor a treatment plan specific to your concerns and desires.

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