Jaw Slimming Injection


Jaw slimming with Botulinum therapy is a noninvasive procedure that is gaining in popularity. BOTOX is used to slim down the jawline by reducing the volume of the chewing muscle known as the masseter. A BOTOX injection causes the muscle to atrophy or thin the chewing muscle or masseter. Beverly Hills plastic surgeon, Dr. Charles Hsu, offers this advanced method of jaw slimming for patients who feel that their jawline is too wide. This can be due to a number of factors, including bone, fat, or an enlarged muscle in the outer lower cheek area, all of which can give a wide appearance in the lower jaw. 

Best Candidates for Jaw Slimming

The best candidates for jaw slimming are:

  • Patients with a wide jawline due to overly large masseter muscle

  • Patients with a desire to improve the appearance of their jaw

  • Patients who want to reduce the flare and width of a wide jaw line without surgery

  • Patients seeking improved facial harmony and a more oval facial shape


During the consultation, Dr. Hsu will first assess the lower outer jaw to see if the masseter muscle is contributing to the widened lower jaw appearance. He will ask for a full medical history and then determine if the patient is a good candidate who would benefit from the injections. Dr. Hsu will work with his patient to develop their custom treatment plan based on their needs and goals. 

Procedure Details

Dr. Hsu can slim the jaw with a neuromodulator injection (such as BOTOX, Dysport, or Xeomin). Dr. Hsu will use a very thin needle to minimize pain and can also use numbing cream if the patient is sensitive to discomfort. Numbing cream typically takes approximately 15-20 minutes to affect patients. Most patients need two treatments, but the range is often 1-3 (spaced one month apart). Overall, jaw slimming is well tolerated and extremely popular in our practice. 


After the injections, patients can return to regular activities immediately. Redness and swelling that occur at the time of injection usually resolve quickly. Any bruising that might occur will usually resolve over a week or two. Some quick tips for the best results:

  • Avoid massaging or touching the injected area afterwards; this may inadvertently cause the botulinum toxin to spread to an unintended area

  • Avoid lying down or inverting the body shortly after injection

  • Avoid strenuous or vigorous activities for the rest of the day after the procedure

  • Ask Dr. Hsu before taking painkillers or medication

From Dr. Hsu

“Jaw slimming with injections started out as something that was done in Asian countries for Asian patients, and I believe that non-Asian patients have yet to discover it. From my perspective, it seems like Asian patients place a very high premium on facial beauty (more than body), and so many of the newest innovations in terms of facial beautification come from Asia. With regards to this procedure, I’ve found that the results are quite good, as long as the reason for the wide jawline is related to large muscle mass in the area. I always check patients for this, but patients can also check themselves by placing their fingers on the angle of their jaw and clenching down. This is an easy way to feel the muscle in the area, and it represents the mass that is targeted with the slimming injection. If the facial width is due to muscle mass, then the injection can work very well. If the facial width is due to bone or fat, then the injection will not work and patients are then better candidates for a jaw shaving procedure, which is an operative procedure. In my experience, most patients need 2 injection treatments for full results. Some patients need 3, and some need 1, but over 80% of my patients require 2 treatments.”

Frequently Asked Questions

  • How does jaw slimming work?

    The idea for jaw slimming is to inject a high dose of a muscle relaxer to weaken the masseter muscles and cause it to atrophy or decrease in size. It will take a couple days to a week to weaken the muscle, but because the purpose is to wait for the muscle to atrophy patients won’t see results until a month afterward. Dr. Hsu’s approach is to titrate the dosage and give a moderate dose initially and then give a second dose a second month if necessary.

  • Is it hard to chew after jaw slimming?

    Most patients do not have trouble chewing after this procedure. However, if a patient does experience some tiring after chewing for a while, this phenomenon is only temporary and will go away over time. 

  • Is jaw slimming permanent?

    Depending on the patient’s age, skin condition, and habits the effects of botulinum toxin could last anywhere from 3-6 months. A follow-up appointment in weeks or months may be scheduled after the injection for re-evaluation, touch-up, or additional treatments as indicated. Since the effect of the botulinum toxin is not permanent, it is best to develop a good relationship with Dr. Hsu and set a schedule for additional injections.