What are the risks of hyaluronidase?

Hyaluronidase is an enzyme which accelerates the absorption of hyaluronic acid based dermal fillers. When used in small quantities it can help to smooth bumpy areas after cosmetic filler injection. When restricted to overfilled areas, the response can take a few days to be noticeable. It does not seem to cause any degeneration of the surrounding normal tissue when used in this manner.

It is not FDA approved for this purpose as no clinical trials have ever been conducted. This is an off label use for a drug which has been used for other purposes for decades.

The main risk with hyaluronidase includes the possibility of reducing normal tissue instead of just filler.  The key is to use an appropriate concentration of hyaluronidase and seek an experienced injector.  Best Dr. Anil Shah

Hyaluronidase is a very safe injectable that can reverse the effects of hyaluronic acid based dermal fillers.  I would recommend that you only visit with an experienced plastic surgeon or dermatologist injector as this is a very nuanced injection technique.  It can be fairly rapid in onset and will not effect the tissue surrounding the injectable filler.  More often, a patient is not asking for complete reversal but rather to address specific concerns associated with their prior injection.

Hyaluronidase is officially approved by the FDA to improve the dispersion and absorption of other drugs, such as anesthetic agents. The use of hyaluronidase to reverse hyaluronic acid fillers such as Restylane, Juvederm, or Perlane, while safe and effective, is not officially approved by the FDA and thus is considered an off-labelled indication. Ideally, allergy testing should be performed along an inner forearm area and observed for 24-48 hours to minimize risk of very unlikely chance of allergic reaction.

The use of hyaluronidase to dissolve hyaluronic acid dermal fillers is very effective and safe. Although its use in this manner is not FDA-approved, this off-label use is very acceptable and beneficial. In fact, using HA dermal fillers anywhere besides the laugh lines (nasolabial folds) is also considered off-label but considered a standard of practice. We know of no adverse events as those suggested in the question.

Hyaluronidase is great at smoothing down bumps from Juvederm or Restylane but may take a few weekly injections and doesn't affect the normal skin at all so it has no permanent problems with regular use.