Quick Facts
- Treatment: Botulinum toxin injected into the masseter, the main chewing muscle
- Uses: Clenching, teeth grinding, jaw tension and a wide lower face
- Session length: 10 to 15 minutes
- Relief from clenching: Within 1 to 2 weeks
- Slimming effect: Gradual, over 6 to 12 weeks
- Duration: Usually 4 to 6 months
What Is the Masseter Muscle?
The masseter runs from your cheekbone to the angle of your jaw. The muscle closes your jaw when you chew. Clenching and grinding make the masseter work overtime. Over time the muscle grows larger, like any muscle trained daily. A large masseter widens the lower face and gives a square jawline.
How Do Jaw Slimming Injections Work?
Your doctor injects small amounts of botulinum toxin into the masseter. The muscle relaxes and clenches with less force. You still chew and talk normally. With less work, the muscle shrinks gradually, and the lower face looks slimmer.
Who Benefits From Jaw Slimming Injections?
- People who clench or grind their teeth, often during sleep
- People with jaw tension, jaw fatigue or tension headaches linked to clenching
- People with a wide or square lower face from a large masseter
- People who want a softer, more tapered jawline without surgery
A wide jaw from bone structure or fat does not respond to muscle relaxation. Your doctor checks the cause first. Jaw joint problems and dental issues need a dentist or specialist assessment too.
What Is the Results Timeline?
| Time After Treatment | What to Expect |
|---|---|
| Week 1 to 2 | Clenching and jaw tension ease |
| Week 4 to 6 | Muscle starts to shrink |
| Week 6 to 12 | Slimming effect visible |
| Month 4 to 6 | Muscle activity returns gradually. Repeat treatment. |
How Do Jaw Slimming Injections Compare to Other Options?
| Option | Main Action | Best For |
|---|---|---|
| Masseter injections | Relax and shrink the jaw muscle | Clenching, grinding, muscular wide jaw |
| Night guard | Protects teeth during grinding | Tooth wear. Does not reduce muscle size. |
| Jawline filler | Adds definition and structure | Soft or undefined jawline |
Many people combine masseter injections with a night guard from their dentist. Some plans add jawline filler for definition. Read more in the face contouring guide.
What Are the Side Effects?
- Tenderness or small bruises at injection points
- Mild chewing fatigue with tough foods for a few weeks
- Rare, temporary smile asymmetry if the product spreads to nearby muscles
Frequently Asked Questions
Do jaw injections stop teeth grinding?
Masseter injections reduce the force of clenching and grinding. Many people report less jaw pain and fewer tension headaches.
Will the injections affect chewing?
You chew normally. Tough foods feel tiring for the first few weeks.
How long does the slimming effect last?
Usually 4 to 6 months per treatment. Regular treatment often keeps the muscle smaller for longer.
Related Guides
- How Long Do Anti-Wrinkle Injections Last?
- Anti-Wrinkle Injections vs Dermal Fillers
- Face Contouring: The Complete Guide
Book a Consultation
Struggling with clenching or a wide jaw? Message us on WhatsApp to book your consultation.
This article is for general educational purposes and does not replace a personalised consultation with a licensed medical aesthetics provider. Individual results vary.