Hyaluronic acid filler during breastfeeding?

While it has not been tested in nursing women, there is no risk of the filler getting into your breast milk. As for the lidocaine, we routinely use lidocaine injections for biopsies and surgeries on nursing women. Hyaluronic acids are also present in every living thing and are not, to my knowledge, at all toxic. I cannot advise you, and I recommend you check with your own doctor and pediatrician, but I know of no risk using hyaluronic acid fillers during breast feeding.

There is little to no evidence pointing to fillers being dangerous or not dangerous. Therefore, just to be on the safe side, it's better that you don't get fillers at all until after you've stopped breastfeeding. 

As there have not been any studies on the effects of hyaluronic acid fillers while breastfeeding, it would be best to avoid it.