100 units of Botox to slim my jawline? Is it too much?

Hi Starfish.  The standard does is 25 units PER SIDE so 50 units total would be average.  100 units sounds like a lot, but having a picture would help us determine if that is a dose we would have recommended.  The location of the dose is usually fairly localized on the lower area of the masseter muscle so injecting "around the jaw" doesn't sound standard.    

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.

The masseter muscles that are injected with Botox to narrow the jawline is a strong muscle that requires more Botox than the usual doses for the forehead and crow's feet.  To have good results, usually at least 25 units are needed and sometimes more.  50 units per side is not uncommon but I do like to start with 25 units and reassess the muscle and add more as needed for the first treatment.  Injecting more Botox than needed most likely will not have any additional effects.  

Typically 25-50 units of Botox is used for reducing the masseter and slimming the jawline. For a first-timer, a lower dose is often advised, but an experienced injector and a particularly large masseter could warrant a higher dose even up front. ~ Dr. Benjamin Barankin, Toronto Dermatology Centre.

Dear Starfish 788. Botox is very useful in slimming of the lower face. A commonly used protocol advises using 30-50 units per side of the face, to be repeated monthly, with a total of 3 injection sessions. Each dermatologist/plastic surgeon/ maxillofacial surgeon determines the exact dosage he uses on a particular patient depending on his own experience , & the size of the masseter he, or she, is injecting. Your physician, most likele decided on the 100 units (50/side) accordingly. 

In general 25 to 30 units of Botox per side (50 to 60 units total) is initially used to reduce the size/strength of the Masseter muscles.  If your muscles were significantly stronger than average a higher dosage may be warranted.  Be certain to follow up with your doctor and let him know if you are experiencing any problems with chewing.  Best wishes.