5 weeks post masseter Botox, is this normal?

Botox for masseter is extremely effective at slimming the jawline when good relaxation of the muscle is achieved.  Especially since you have noticed your masseters have gotten softer, the muscle will show a visible difference in size over the 3-4 months that the Botox is active.  Most patients will see a slimming effect in 4-6 weeks after treatment, but rest assured that the muscle will continue to slim over the next 3-4 months.  

Botox works by affecting the nerves which go to specific muscles. The muscles then over time as they aren't "exercising" will become less bulky. This takes time and multiple treatments thought to get this result. So be patient and talk with your practitioner about yoru concerns. I hope this was helpful.

 I expect to see softening of the master muscles with less clinching after Botox. The masseter is a big muscle and I would not expect to see atrophy five weeks after a single injection of Botox. In fact I would caution patients against trying to create muscle atrophy with Botox. This  likely will require multiple injections over a long period of time and may or may not yield results. I find Botox to the masseter is great for functional improvement but desired muscle atrophy might be harder to achieve. 

 Thank you for your question. Photographs would definitely be helpful to assess your concerns in more detail. I would expect you to see some visible changes after 50 units on each side, as this is a fairly strong dose. There is a possibility, that the Botox is not going directly into the target muscles, but instead into the surrounding tissues. I would revisit with your injector, and follow up.  

Thinning or narrowing the lower face can be achieved with Botox injections to the Masseter muscle. However, the effect won't be visible immediately since it requires multiple serial treatments and time.The masseter muscle ( masticatory muscle) gives soft tissue bulk to the lower face specially around the angle of the jaw. Botox, by weakening the masseter muscle, could decrease the bulk of the muscle that ultimately will result in decrease width of the lower face. However, this WON'T happen fast or overnight.Since the masseter muscle is used to chew food, it is being exercised everyday several times a day. Like a person that goes to the gym and has big muscles due to exercise, the fact that you stop going to the gym for few weeks ( e.g. because she/he is on vacation), doesn't mean the muscles will shrink right away during that period of time. However, if that person gets a leg fracture and has to stay away from the gym several for months, eventually her/his muscles will shrink due to lack of exercise.  Therefore, in order to reduce the size of the masseter muscle, you need to put it in a "Botox cast" for several months with serial treatments.John Mesa MD
Board Certified Plastic Surgeon
New York City (#NYC) & New Jersey (#NJ)

Depending on the size and strength of your Masseter muscles, it may take several treatments for shrinkage to occur. It is a good sign, however, that you notice softening of the muscle. Follow your doctor's directions, good luck!

Hi thereThanks for the question.  Botox will start working pretty quickly in terms of relieving symptoms and controlling grinding.  However, the atrophy of the muscle will take months to make a dramatic effect.....but it will happen. Eventually the muscles will slim down as they are not being used as much and that will slim out your face and change your square shape to a oval shape.  See my blog below for additional information. 

It will take several treatments usually spaced 8 to 10 weeks apart to achieve the most rapid results.  The intramuscular placement of the Botox is also important. Best of luck,Suneel Chilukuri, M.D.

It can take several treatments with botox for the master to shrink a bit, and it hast to be repeated regularly. Be patient and repeat the treatment. Best of luck.

Thanks for your question.  50 units each side seems like a lot to me, but it is hard to estimate what would be needed without a picture or in-person exam.  Don't worry -- muscle atrophy takes months to occur.  It may even take a few sessions for it to occur (meaning a repeat session once the effect of the botox wears off).  Think of it like any other muscle (like the biceps) - it takes a while for it to atrophy.