Hyaluronidase: how long it takes to work and how much it swells
Hyaluronidase usually starts working right after the injection: patients often notice a reduction in volume within the first hours or the next day. What causes confusion is that the injection itself causes swelling, so the face may look "worse" on the first day before showing the result. In general, the final assessment is made once the swelling goes down, between a few days and two weeks, at the professional's discretion.
This page is for you to explain to the patient what to expect in the days after the enzyme, whether for an aesthetic correction or after a complication. If the question is whether the enzyme removes all the product or causes sagging, see does hyaluronidase remove all the filler?.
How does hyaluronidase work?
It is an enzyme that breaks the chains of hyaluronic acid into smaller fragments, which the body eliminates. That is why it acts on hyaluronic acid fillers, and not on biostimulators, PMMA or other materials.
The perceived speed depends on several factors: how much product there is, how long ago it was injected, how it is distributed, the type of gel (more or less cross-linked) and the technique used. That is why two patients with the same concern may respond differently.
Timeline: what usually happens after the injection?
| Moment | What usually happens | What to advise |
|---|---|---|
| During and right after | Temporary stinging or discomfort, redness, slight swelling | Normal; observe in the clinic |
| First hours | Start of reduction in the treated volume, added to the swelling from the injection | Do not judge the result yet |
| 24 to 48 hours | Peak swelling; bruising may appear | Cold compress if advised, head raised when sleeping |
| 3 to 7 days | Swelling subsiding; bruise changing color | Follow the instructions; avoid touching the area |
| 1 to 2 weeks | Area closer to its final appearance | Follow-up visit to assess |
| After stabilization | Time to decide whether another enzyme session or a new filler is needed | Reassessment with comparison photos |
The timeframes are usual ranges and vary. In areas of thin skin, such as the tear trough, swelling may last longer.
How long does hyaluronidase cause swelling?
The swelling comes from two sides: the injection itself, which causes mild inflammation, and the tissue's reaction to the breakdown of the gel. In general, it is most visible in the first 24 to 48 hours and improves over the week. Lips and the tear trough tend to swell more than other areas.
Swelling that gets worse after the third day, that comes with heat, increasing redness or intense itching, or that spreads far from the treated area, is not the usual pattern and should be assessed. It may indicate inflammation, infection or a hypersensitivity reaction.
Does hyaluronidase cause bruising?
It can. Any injection can rupture small vessels and leave an ecchymosis or, when more blood collects, a hematoma. The bruise usually changes color (purple, greenish, yellowish) and disappears within one to two weeks. Anticoagulants, some supplements and highly vascular areas raise the chance.
How many sessions are usually needed?
It depends on the goal. To reduce a slight excess, one session is sometimes enough. To remove older product, in larger amounts or more cross-linked, more than one may be needed, with an interval to reassess between them. Doing it in stages also avoids removing more than necessary.
| Situation | Usual tendency |
|---|---|
| Small, recent excess | One session usually resolves it |
| Bluish tone (Tyndall effect) | One or more sessions, depending on the response |
| Old product, large volume or several layers | More than one session, in stages |
| Suspected vascular occlusion | Emergency response, with close reassessment; does not follow the aesthetic logic |
When can you fill again?
There is no single timeframe. The most common approach is to wait for the swelling to go down and the area to stabilize, and then reassess with standardized photos. At that point, three outcomes are common:
- the patient liked the look without product and does not want to replace it;
- a smaller volume, in another position or with a different gel, works better;
- the original concern calls for another approach, not filler.
Replacing too quickly, while still swollen, increases the chance of getting the volume wrong. The most common mistakes that lead to the enzyme are in excess volume after filler and, for the eye area, in under-eye filler that went wrong.
Precautions usually advised afterward
- Cold compresses in the first hours, if the professional advises it.
- Avoid massaging the area, unless specifically advised.
- Avoid intense heat, saunas and heavy exercise on the first day or the days the professional indicates.
- Do not apply anything new to the area until the follow-up.
- Report strong itching, red patches, swelling outside the treated area or shortness of breath.
What about hyaluronidase ointment?
Patients sometimes ask whether there is a cream version to "dissolve at home". The question has its own page: does hyaluronidase ointment work?. In short, filler correction is done by the professional, with the injectable enzyme and an assessment.
In Harmy, the projection can be redone at the reassessment, with the new photo and the ml revised. That way, before replacing the filler, the patient sees an illustrative simulation of the more discreet volume you agreed on.
Frequently asked questions
How long does hyaluronidase take to work?
The enzyme starts acting on hyaluronic acid right after the injection, and a difference is often noticeable within the first hours or the next day. The final result, however, is usually assessed once the swelling from the injection goes down, generally between a few days and two weeks.
How long does hyaluronidase cause swelling?
In general, swelling is greatest in the first 24 to 48 hours and eases over a few days. The time varies with the area, the volume treated and each person's reaction.
Does hyaluronidase cause bruising?
It can, like any injection. Bruising usually changes color and fades within one to two weeks. A bruise that grows, severe pain or pale skin call for immediate contact with the professional.
How long after hyaluronidase can I fill again?
There is no single timeframe. It is usual to wait for the area to calm down and stabilize, and then reassess whether a new filler is truly indicated. The decision is up to the qualified professional, after assessment.
Harmy images are illustrative simulations generated by AI from the patient's photo to support the conversation between practitioner and patient. They are not a promise of results. Indication, technique, product and volume are solely the decision of the licensed practitioner. This content is for information only and does not replace a clinical assessment.