I Had Botox in my Masseters 2 Days Ago, when I Can Expect to Notice Any Effect? (photo)

I had botox injected into my masseters for jaw reduction and to stop my clenching and grinding two days ago. I don't see or feel any change yet. Can you tell me when I can expect to notice any changes and what they might be? The doctor said I should probably come back in 9 month's time for more injections but I don't know how much botox he used, he injected at 4 sites on both sides.

Doctor Answers 16

Timeline for masseter injection

The sequence is the following:
1) botox injection 
2) within 2 weeks, you should feel that your muscles can't clench down as hard
3) Over the course of the next many weeks, the masters will slowly shrink and your face will slowly slim. This is due to the muscle atrophying as a result of not working as hard (analogy: if you have your arm in a cast for a few weeks, it will be smaller than the other arm when the cast comes off).

People normally notice reduction in grinding/clenching and less discomfort/tension within the first couple weeks.  The changes in facial shape are more gradual.


Houston Dermatologic Surgeon
5.0 out of 5 stars 12 reviews

Botox and Masseters Muscle

Most of my patients begin to see and feel the effects within two weeks. That muscle is extremely strong and so it does require a bit longer than the forehead muscles to fully react. It will get better, but you should start noticing things changing within a few weeks. You will notice a lessening of the tension in that muscle and less of the strain. I usually see people back within 6 months, especially ones I treat for TMJ, because they can start feeling the Botox wearing off about that point and I prefer they don't get back to baseline again, and so do they!

F. Victor Rueckl, MD
Las Vegas Dermatologist
4.6 out of 5 stars 17 reviews

Botox dosage for masseter and timeline

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.

Young R. Cho, MD, PhD
Houston Plastic Surgeon
4.8 out of 5 stars 38 reviews

Botox Results in Masseter

Botox usually takes 2 or 3 days to start to work, and will continue to improve over the first 7 to 10 days. Once the effect starts to wear off, you will need a repeat treatment to maintain results. Some find that the effects last longer after having multiple treatments, even up to a year.

Jerome Edelstein, MD
Toronto Plastic Surgeon
5.0 out of 5 stars 179 reviews

Botox and Dysport for masseter reduction, "V-line"

You won't see a change until about 7-10 days.  Depending on the dosage used by your physician, and where in the body of the masseter muscle he injected, the degree of "tapering" and change will vary.  Typically 4-5 injections are performed on each side along the inferior border of the muscle, but taking the injections more superiorly does help to enhance the final result.  The Botox will have worn off in 3-4 months, so 9 months is too long to wait for a repeat injection.  Even with the largest muscles you will see a visible reduction in size with proper technique after one injection, though you may not achieve the maximal reduction possible with Botox until you have had 2-3 sessions.    

Donald B. Yoo, MD
Beverly Hills Facial Plastic Surgeon
4.9 out of 5 stars 58 reviews

Botox Results in Masseter

Usually two weeks after Botox injections patients begin to see and feel a difference from the injection. Because the muscle is so strong, it requires a bit longer than the forehead muscles to fully react. You will notice a lessening in the strength and degree of the muscle over the next few weeks. Visual reduction may take a few months and we usually retreat at 3-4 months and then wait another 6 months for full visual shrinking of the musculature.


My best, 

Dr. Anil Rajani

Anil Rajani, MD
Portland Physician
4.8 out of 5 stars 46 reviews

Masseter muscle Botox

The masseter muscle is one of the muscles activated during chewing. It’s located at the “angle of the mandible”, or “angle of the jaw”. Masseter muscle hypertrophy is enlargement of the masseter muscle, and can contribute to a harsh, square look at the angle of the jaw. Botox can be used to relax this muscle, and to soften the look of the lower face. I usually start with 50 units of botox (25 units on each side). When Botox is used to relax the facial muscles that cause fine line, the maximum effect is seen in 7-10 days. When Botox is used to reduce masseter muscle hypertrophy, the maximum effect is not seen for 3 months. Results can last up to 9 months. I recommend repeat injection every 6 months if you would like to maintain your results. 

Dara Liotta, MD
New York Facial Plastic Surgeon
4.9 out of 5 stars 31 reviews

Botox and Masseter muscle

It generally takes 2 weeks or more for the muscle to shrink. Over time you may need additional Botox in this area to shrink the muscle. Botox lasts 4 to 6 months in this area and with repeated injections you will continue to have improved results. Best, Dr. Green

Michele S. Green, MD
New York Dermatologist
5.0 out of 5 stars 78 reviews

Muscle thinning in the masseters for teeth clenching may take a while after Botox treatment

Usually Botox injected in the masseter muscles can minimize teeth clenching, not grinding. After the clenching diminishes, the muscle starts to become less hypertrophied, or bulky. Just like a weight lifter who stops working out; the muscles are still going to be bulky for a while. There is a gradual diminishing of girth.

Ronald Shelton, MD
Manhattan Dermatologic Surgeon
4.9 out of 5 stars 38 reviews

Give the Botox a few more days to take affect for relief and results

Hi and great question! Botox does take a few days (7-14 average) to take affect and it is not concerning yet that you haven't noticed change. Always be confident that you can follow up with your provider after 2 weeks if you aren't noticing relief or affect. Dosage is commonly communicated in our practice for patient education purposes, but it's a benefit to you and your provider to have excellent communication so the appropriate dosage is administered. I also agree that 9 months seems a lengthy distance between appointments as the Botox will commonly wear off 3-4 months following treatment. There are patients who do see longer effects with treatment, but once you get the first concern out of the way- being certain that the Botox is dosed appropriately and you have results you're pleased with- it will also benefit you to assess yourself 3-4 months from now. With repeated treatments of Botox, the muscles do not have the opportunity to gain full strength and go back to "pre-treatment" state. This is true of dynamic muscle activity anywhere Botox is effective. Again, it's too early to worry about the treatment you just received, but don't ever hesitate a follow up to the office 14 days following treatment if you're unsatisfied with the results. Sometimes a few more units are needed and it's best to not overtreat initially. It's also not a good idea to assess too early, or before the 2 week period. I hope this brings confidence in the treatment and helps you to know experiencing little change thus far is very normal.

Gregory Mesna, MD, FACS
Minneapolis Plastic Surgeon
4.8 out of 5 stars 21 reviews

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.