Hyaluronidase: how a filler is dissolved

Hyaluronidase is an enzyme that breaks down hyaluronic acid. It is what makes hyaluronic acid filler reversible — and that reversibility is probably the strongest argument in favor of this type of product over every other injectable.

The body produces hyaluronidase naturally; that is how filler is reabsorbed over time. Injecting the enzyme simply speeds up, in a targeted way, a process that would happen anyway.

What hyaluronidase is used for

Two completely different situations, and they are worth separating because the urgency is not the same.

Aesthetic correction

The result was disappointing, there is too much volume, asymmetry, product that has migrated beyond the border, or a visible nodule. This is an elective decision, made calmly, usually after the initial swelling has settled and the real result has emerged.

Vascular emergency

Filler has compressed or blocked a vessel, compromising blood supply to the skin. Here hyaluronidase stops being an aesthetic tool and becomes urgent care: dissolve the product as fast as possible to restore flow.

It is because of this second situation that any clinic injecting filler needs hyaluronidase available on site — not orderable, available. Asking about this before booking is legitimate, and revealing.

How it works and how long it takes

The enzyme, registered with Anvisa, the Brazilian health regulator, for injectable use, is applied in the area where the product sits and begins to act within minutes. The visible effect generally appears between 24 and 48 hours, stabilizing at around two weeks.

In aesthetic corrections, more than one session is commonly needed. Denser, more cross-linked fillers resist longer, and the practitioner usually prefers to dissolve gradually, reassessing between sessions — which is more prudent than dissolving everything at once.

Does hyaluronidase dissolve every filler?

No. And this is the most important information in this article.

It dissolves hyaluronic acid only. It does not act on:

• Calcium hydroxylapatite (Radiesse)
• Poly-L-lactic acid (Sculptra)
• PMMA and other permanent fillers
• Industrial silicone
• Thread lifts

In other words, reversibility is not a feature of "filler" in general — it is a feature of one specific type of filler. Anyone who received a permanent product and regrets it does not have that exit, and management becomes far more complex, sometimes surgical.

That is why, for someone starting out, hyaluronic acid is the more prudent choice: it comes with a way out.

What are the risks of hyaluronidase

Allergic reaction. This is the most significant risk. Hyaluronidase is a protein of animal origin in most preparations, and reactions — from local to anaphylactic, though the latter are rare — are documented. For that reason it should be injected in a setting equipped to handle an emergency, not just anywhere.

Loss of your own hyaluronic acid. The enzyme does not distinguish injected product from the natural hyaluronic acid in your tissue. The loss is temporary and the body replaces it, but in the first few weeks the area can look more deflated than it did before any filler. That frightens anyone who was not warned.

Unpredictable amount of dissolution. It is hard to dissolve exactly half of something. The result can fall short of or go beyond what was intended, which reinforces the logic of dissolving gradually.

Swelling and bruising, as with any injection.

How long the swelling takes to go down

Swelling from the injection itself usually lasts two to three days. The result of the dissolution is assessed after that — and full stabilization takes around two weeks.

Redoing filler in the same area means waiting out that period. Injecting new product into tissue that still has active enzyme in it wastes the product.

Cost and number of sessions

The price depends on the amount of enzyme and the number of sessions. Dissolving usually costs less than filling, but the figure that matters is the protocol: a case with extensive excess can require three or four spaced-out sessions.

One point of commercial honesty is worth stating: a clinic that placed the filler and needs to correct a result it produced itself should treat that as part of the service, not as a new procedure. Asking what the policy is in that case, before being injected, tells you a lot.

When we advise against it

• Before day fifteen after the filler. What is bothering you may be swelling, not product. Dissolving in that window is dissolving an impression.
• Out of dissatisfaction immediately after the injection. An honest assessment is only possible once the swelling has settled.
• When the product is not hyaluronic acid. It does not work, and injecting anyway exposes the person to the enzyme's risk with no benefit at all.
• When the complaint does not come from the filler. Sometimes what bothers someone is aging in another area, and dissolving what is there does not fix it — it only removes something that was helping.
• In a setting not equipped to manage an allergic reaction.
• Without knowing what was injected. Before dissolving, you have to find out what is in the tissue — through history, clinical examination and, when necessary, imaging.

Frequently asked questions

What does hyaluronidase do?

It breaks down hyaluronic acid. In aesthetic practice, it is used to correct or remove filler and to treat a vascular emergency caused by obstruction.

How much does hyaluronidase cost?

It depends on the amount needed and the number of sessions. Worth knowing that dissolving frequently costs less than filling, but may require more than one session.

Does hyaluronidase hurt?

Discomfort comparable to filler, sometimes with a burning sensation during the injection. It is quick.

Does hyaluronidase work for under-eye circles?

It works to dissolve poorly placed filler in the under-eye area — a frequent indication, given how little margin that area allows. It does not treat dark circles from other causes.

Can it go wrong?

It can, as with any procedure. The scenarios are allergic reaction, dissolving more than intended, and an asymmetric result. All are reduced by fractionated injection, an appropriate setting, and assessment between sessions.