Hyaluronidase is an enzyme that quickly breaks down hyaluronic acid, the main component of many dermal fillers. It acts by hydrolyzing the glycosidic linkages within the hyaluronic acid molecules, reducing their viscosity and structure. In an aesthetic setting, its primary function is to dissolve unwanted filler, correcting issues like overfilling, asymmetry, or misplaced product. It is also used for complications such as vascular occlusion, where filler obstructs a blood vessel. Beyond cosmetic uses, hyaluronidase increases tissue permeability, aiding the dispersion and absorption of other injected medications.
The Immediate Onset of Action
The enzymatic breakdown of hyaluronic acid filler begins almost instantaneously upon contact with hyaluronidase. Within the first few minutes after injection, the enzyme starts cleaving the bonds that hold the filler gel together, causing the material to soften and break apart. This rapid action means that in some cases, patients may observe a visible reduction in the volume of the filler within 5 to 15 minutes of the treatment.
This immediate effect is particularly noticeable with softer, less cross-linked fillers, which are easier for the enzyme to penetrate and degrade. For emergency situations, such as a vascular occlusion, this rapid onset is necessary for restoring blood flow to the affected area. While the enzyme has a short half-life, its initial activity is rapid and pronounced.
The duration of hyaluronidase activity in the tissue is relatively short, typically lasting between 24 and 48 hours. The initial softening or flattening seen within the first 30 minutes to two hours represents only the start of the dissolution process. Complete reduction of the filler volume takes additional time, as the body needs to absorb the newly fragmented hyaluronic acid molecules.
Factors Influencing Dissolution Speed
The speed and completeness of filler dissolution are influenced by characteristics of the filler and the treatment protocol used. The type and density of the filler material determine how quickly it breaks down. Fillers are chemically cross-linked for stability, and those with a higher degree of cross-linking are more resistant to enzymatic degradation.
Denser, highly cross-linked fillers, often called monophasic fillers, require a higher dosage of hyaluronidase and take longer to dissolve than softer, biphasic fillers. The dosage of hyaluronidase used is a primary factor in the treatment’s success and speed. A higher concentration generally means faster action, but the optimal dose is tailored based on the volume and specific type of filler being addressed.
The total volume of filler also plays a role, as a larger mass requires more enzyme and time to degrade completely. The molecular structure of the gel affects enzyme dispersion; cohesive gels may require multiple injection points or massage to ensure thorough penetration. These variables explain why the full extent of dissolution unfolds over the following days, beyond the immediate results.
The Full Resolution Timeline and Aftercare
While the enzyme’s work is fast, the full, stable result is not immediately apparent. Swelling and inflammation are common after hyaluronidase injection and can temporarily mask the true extent of the filler dissolution. This residual swelling can make the area appear puffy or asymmetrical, which can be discouraging if the final outcome is expected instantly.
The majority of the filler breakdown occurs within the first 24 hours, but an accurate assessment of the final result is usually made after a few days. Most patients see significant swelling resolve and a clearer indication of results within 48 to 72 hours. However, final tissue normalization, where all residual swelling and bruising have subsided, often takes between one and two weeks.
Proper aftercare during the recovery period supports the healing process and ensures the best outcome. Patients are advised to avoid strenuous exercise for 24 hours and refrain from rubbing, massaging, or applying pressure to the treated area on the day of the procedure to prevent enzyme displacement. A follow-up assessment is usually scheduled around the two-week mark to determine if all the filler has been dissolved and if any further treatment is needed.