A well-defined, balanced jawline is often associated with facial harmony and attractiveness. However, for some people, prominent or enlarged jaw muscles—known as the masseters—can create a square, wide, or overly masculine appearance. While genetics and bone structure play a role, lifestyle habits such as teeth grinding (bruxism) and frequent chewing can cause the masseter muscles to enlarge over time.
Fortunately, you don’t need surgery to achieve a softer, slimmer jawline. Masseter reduction using injectable treatments has become one of the most popular and effective non-surgical jawline contouring solutions available today.
Understanding the Masseter Muscle
The masseter is a powerful muscle located at the back of the jaw, responsible for chewing and jaw movement. When overdeveloped, it can:
Make the lower face appear wider or more square-shaped
Create facial asymmetry
Contribute to tension headaches and jaw discomfort in cases of bruxism
Reducing its size can lead to a more tapered, oval, or V-shaped facial profile.
What Is Masseter Reduction?
Masseter reduction is a non-invasive cosmetic procedure that involves injecting botulinum toxin type A (commonly known as Botox®, Dysport®, or Xeomin®) into the masseter muscles. This relaxes the muscle activity, which in turn causes the muscle to gradually shrink over several weeks.
Key benefits:
Slimmer, softer jawline
More feminine or balanced facial proportions
Reduction in teeth grinding and jaw clenching symptoms
No downtime compared to surgical options
How the Procedure Works
Consultation
Your provider will assess your facial anatomy, muscle size, and treatment goals. They may ask about any history of jaw pain, grinding, or past cosmetic procedures.Preparation
The area is cleaned, and in some cases, a topical numbing cream is applied.Injection Process
Using a fine needle, botulinum toxin is injected into each side of the masseter muscle. The number of units used depends on the muscle size and desired result.Post-Treatment Care
No rubbing or massaging the treated area for at least 4 hours
Avoid strenuous exercise for 24 hours
Normal eating and speaking can resume immediately
Treatment time: Around 10–15 minutes
Downtime: None—most people return to work right after the session
When to Expect Results
Initial changes: 2–4 weeks after treatment
Full slimming effect: Around 6–8 weeks
Duration: Results typically last 4–6 months; with repeated treatments, the effects can last longer as the muscle naturally reduces in size
Ideal Candidates for Masseter Reduction
You may be a good candidate if you:
Have a square or wide lower face due to muscle enlargement (not bone structure)
Desire a softer, more tapered jawline
Experience jaw clenching, teeth grinding, or tension headaches
Want a non-surgical alternative with minimal downtime
Safety and Potential Side Effects
When performed by a qualified, experienced provider, masseter reduction is generally safe. However, potential side effects can include:
Mild bruising or swelling at injection sites
Temporary chewing weakness (especially when biting hard foods)
Slight asymmetry if the injections are uneven
Choosing a skilled injector is essential to avoid over-relaxing the muscle, which could affect your smile or chewing comfort.
Masseter Reduction vs. Surgical Jawline Contouring
Non-surgical (Botox):
Quick, no downtime
Temporary (must be maintained)
Lower cost upfront
Subtle, natural-looking results over time
Surgical jaw reduction (mandibular contouring):
Permanent changes
Requires general anesthesia and significant downtime
Higher cost and greater risk of complications
For most people seeking a mild-to-moderate change in jawline shape, non-surgical masseter reduction offers a safer, more convenient first step.
Combining Masseter Reduction with Other Treatments
For enhanced facial contouring, masseter reduction can be paired with:
Dermal fillers to define the chin or jawline
Ultrasound or radiofrequency tightening for skin firmness
Cheek filler to balance proportions
Botox in other areas (forehead, crow’s feet) for a more refreshed look
Final Thoughts
Masseter reduction is a powerful yet subtle way to transform the face without surgery. By reducing the size of overactive jaw muscles, it creates a slimmer, more harmonious lower face, while also offering relief from bruxism symptoms. With minimal downtime, natural results, and a high satisfaction rate, it’s no surprise this treatment is a favorite among both men and women seeking modern facial contouring solutions.
If you’re considering this procedure, choose a licensed, experienced injector who understands facial anatomy and can customize your treatment for both aesthetics and function.
