Without having Ultherapy, some patients have had delayed bad reactions to silicone injections. Some immune reactions can occur (granulomas) that develop large bumps under the skin and swelling and redness and pain. This is extremely rare with other fillers such as Voluma, Juvederm, Belotero and Restylane (the hyaluronic acid fillers). There might be an increased risk of developing the immune reaction to Silicone if the Ultherapy energy breaks apart the silicone filler and exposes it more to the body's immune system. This is only a theoretical question and has not been proven. So it's best to avoid if possible, delivering Ultherapy treatment immediately over the Silicone-treated area. I, however, have not been made aware of any cases of such complications.