If you are not using a guard, and did the botox more for cosmetic treatment in the jawline area, nothing stops your muscles from gaining strength back, and the duration of action will likely be less than 6 months. Whether it's windows, mac, ios or android, you will be able to download the images using download button. Jaw Reduction And Jawline Reshapingmasseter Muscle Relaxed Using Botox Cosmetic Chicago Botox Expert Performed By Cher Botox Cosmetic Botox Muscle Relaxer However, it can take several weeks for the masseter muscle to begin atrophying. How long does botox take to work masseter . Botox usually takes about 4 days to work. If you are using mobile phone, you could also use menu drawer from browser. When injected with botox, these muscles are simply unable to get their workout and finally begin to rest, allowing them time to heal and repair. How much is typically needed and how long does it take to kick in? The jawline botox procedure takes about 15 minutes, in...