Preservatives in hyaluronic acid dermal fillers e.g. Restylane, Juvederm, Perlane?

There are no preservatives in these dermal fillers that you mentioned.  That is why they are single use only.

The hyaluronic acid products available in the United States do not contain preservatives.  This is why they are approved for single use only.  That is to say, once opened the product should be used and not stored due to the potential risk of contamination developing as an open, unpreserved product is allowed

Dear heygoodlooking,Whereas
in the United States we have only a handful of FDA approved HA fillers, the
European market has approved over 75 HA filler products. Be wary of knockoffs or uncertified medical individuals as well. You are in the best hands when you consult a board certified facial plastic surgeon.