How Much Units of Masseters Botox to Start With?

My Doctor is compelling me to go for Masseters Botox, he said 2 sittings will be required, at first sitting he would inject 100 units of Botox at each side and after 6 months one more sitting will be required. I think 100units on each side is a high amount to start with, but my Dr says, for effects to show min 75units must be injected , less than that does not work. I have been reading here at realself people getting benefited from even 25units. Please guide me.

Doctor Answers 14

Don't let anyone "compell" you to have botox anywhere you don't want...

if you and the doctor agree your masseter muscles are too large and you want to improve your look, then of course botox is the perfect solution to the the old days, massive amounts of botox were used, but today we know the same benefits accompany much smaller doses...I frequently start with only 15 units per side and if needed add a little more in a month or so...then the results typically last for about a year...most doctors tend to use slightly higher doses...about 25-35 units/side...

Las Vegas Dermatologist
4.6 out of 5 stars 9 reviews

Botox and Masseter muscle

Botox in the Masseter muscle generally takes 15 to 20 units on each side to have the desired effect. It can take several weeks for the muscle to decrease and notice the facial slimming and sometimes a second course of Botox is needed. Please consult an expert in Botox. Best, Dr. Green

Botox masseter dosing

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.

Botox 75 Units Per Masseter?

75 units of Botox per masseter is not necessary.  The doctor is most likely referring to Dysport, which is about 3:1 Botox.

Botox and the masseter muscles

The number of Botox units required depends on the strength of your masseter muscles, your gender and the shape of your face.  Most people benefit from 20 to 40 units per side.  100 Botox units per side is excessive.  Did he mean Dysport units?  If you are interested in treating your masseter muscles, either discuss the product and amount with your doctor or seek another opinion.

Martie Gidon, MD, FRCPC
Toronto Dermatologist
5.0 out of 5 stars 22 reviews

Depends on the patient

You are correct that 100 U on each side sounding excessive. Generally at a minimum we start treating at 20u/side, and increase all the way up to 50u/side depending on the size of the muscle. Perhaps they were referring to Dysport units, which would make more sense of 50-80 units per side. Have your physician clarify with you which toxin is recommended and the difference in conversion of units.

David W. Kim, MD
Bay Area Facial Plastic Surgeon
4.7 out of 5 stars 35 reviews

Appropriate dosage for Botox and Dysport for masseter reduction, "V-line" procedure

100 units for each side is excessive.  You should notice a marked improvement with an initial treatment of 25 units per side.  With serial treatments, even with 20 units per side it should be possible to virtually eliminate the activity of the masseter muscle causing the bulky appearance along your jawline.  

Even for Dysport, 100 units is excessive.  50-70 units per side with Dysport produces excellent results.  

Donald B. Yoo, MD
Beverly Hills Facial Plastic Surgeon
5.0 out of 5 stars 48 reviews

Botox for masseter muscle reduction

I recommend 40-50 units and that seems to be effective in my practice - it is very important to have someone inject masseter muscles who has exerience doing it. You can always add more ... and good follow-up is a must.

Botox for jaw reduction

Dear pari1987,

  • I like starting with 30 units on each side and bumping up the dosage as needed
  • If you can still clench your jaw after 2 weeks, then we add more
  • Some people do start with 100units so everyone is a little different

Best regards,

Nima Shemirani

Nima Shemirani, MD
Beverly Hills Facial Plastic Surgeon
4.9 out of 5 stars 71 reviews

Masseter requires much smaller dose

The masseter is a thick, somewhat quadrilateral muscle, consisting of two parts, superficial and deep. The fibers of the two portions are continuous at their insertion. The masseter muscle is sometimes the target of plastic jaw reduction surgery.The superficial portion, the larger, arises by a thick, tendinous aponeurosis from the zygomatic process of the maxilla, and from the anterior two-thirds of the lower border of the zygomatic arch. Its fibers pass downward and backward, to be inserted into the angle and lower half of the lateral surface of the ramus of the mandible.
Deep.  The deep portion is much smaller, and more muscular in texture. It arises from the posterior 3rd of the lower border and from the whole of the medial surface of the zygomatic arch. Its fibers pass downward and forward, to be inserted into the upper half of the ramus and the lateral surface of the coronoid process of the mandible.

The deep portion of the muscle is partly concealed, in front, by the superficial portion; behind, it is covered by the parotid gland.


I use 5 units of Botox with a 90% response rate for grinding and for reduction 15-20 units per side



Arnold W. Klein, MD (in memoriam)
Beverly Hills Dermatologic Surgeon
4.8 out of 5 stars 5 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.