I got Bellafill 2 weeks ago in my chin. 2 syringes. How soon can I add more? I still have weak chin.

I would recommend waiting at least 6-8 weeks after your first Bellafill treatment before adding more to your chin.  It will take this long to see the results from your first treatment and thus it will more easily be seen how much more you may need.  

Two weeks is the standard downtime prior to adding anymore injectables as it takes at least 2 weeks for the filler to integrate with your skin. Moreover, if you are still experiencing pain in the injected area, I would advise waiting an additional 7-10 days prior to pursuing any further injections. I suggest following up with the medical professional who administered your first round of bellafill. Best, Dr. Emer

i generally wait a month between treatments because i want to give the implant time to begin to get a network of vessels and collagen.. I think there is a point of diminishing returns if you put in too much in one place at one time.. I would rather do one or two syringes in an area and come back for more sessions.