Why Didn't Botox Work on my Masseter Muscle?

Dear Chubby,
Masseter BOTOX treatments take a few weeks to be seen. Occasionally, a before and after photo comparison is needed to really understand what if anything was accomplished.
One issues is whether the fullness of your face is from muscle or primarily fat. Muscle responds to BOTOX but not fullness from fat. In which case, facial liposuction maybe beneficial.
The next issue is dose. I recommend that you do your homework and find the leading physician doing these treatments in your area. You may pay a little more for a visit with them but then you are much more likely to achieve your goal.

Thank you for your question. Botox in the masseter region usually takes longer than in the standard areas to take effect. I tend to use anywhere from 15 units (conservative treatment) to 50 units (for someone with really strong masseters) on each side to get the desired result. It may start within the first week but I tell my patients to wait three weeks before doing a more thorough evaluation. The treatment typically lasts longer than the forehead/crows feet/frown regions. It is also a gradual onset of the return of masseter function. I have tried the masseter injections myself and space the treatments around 4 months apart, but use smaller doses to maintain the effect. I normally know the effects are wearing down when I start to clench my teeth more heavily at night when asleep. Once you stop using Botox, the masseter muscles will return to their original baseline when the effects of Botox wears off completely.This region is considered a more advanced technique, so I would make sure you go an experienced injector.

I would wait 14 days to see your maximal result. Each muscle group
responds differently, so it may just take more time. However, it is also
possible that you need more Botox injected to have the
effect you want, and this could be determined at your followup appointment with your injector. You may require a higher dosage as you suggested, or the right muscles were not targeted.