Thank you for your question.
There's a couple of reasons why you could be "botox resistant".
1. Maybe the botox has worked very well and you do not have enlarged masseter muscles anymore, therefore, injecting more toxin will not shrink your jawline any further.
2. There are some people who develop antibodies to botox. You may need to use a different brand of toxin if your masseters are still hypertrophic.
The only permanent ways to reduce your jawline are surgical. Either your muscle can be reduced or your mandible can be reduced or both.
Hope this answers your question.
