The Journal
Written by: ACRE | Published On: March 04, 2026
Practitioners’ Complete Guide to Masseter Botox: What is it and How Long Does it Last?
Masseter Botox is a treatment used to give patients a slimmer, more defined jawline. This aesthetic, non-surgical treatment is popular for its long-lasting results, but how long does Masseter Botox last, and does the treatment have any side effects?
Provide your patients with all the answers they need with the help of this expert guide, covering everything from simple definitions to how quickly Masseter Botox takes to work.
What is Masseter Botox?
Patients may know what results they want to achieve but not know what Masseter Botox is, so providing a clear definition is important. This treatment involves the application of botulinum toxin to the masseter muscles of the jaw in order to weaken them. This relaxes the muscles, providing a slimmer and more defined jawline.
While Masseter Botox offers aesthetic results, some patients may also want the treatment in order to address functional issues, such as bruxism (teeth grinding) or temporomandibular joint (TMJ) dysfunction (jaw pain or clicking).
How Does Masseter Botox Work?
Masseter Botox is a quick and simple procedure for patients. Small, controlled doses of botulinum toxin are injected using needles on both sides of the jaw to block the nerve pathways responsible for muscular contractions.
Once this Botox® has been applied, the masseter muscles will begin to relax, shrinking down over time. Meanwhile, the surrounding muscles retain their size, accentuating the jawline.
Patients who have Masseter Botox can look forward to a number of key benefits, including:
- Slimmer jawline
- Improved facial symmetry
- More defined contouring
- Relief from jaw clenching
- Relief from jaw pain and clicking
How Long Does Masseter Botox Take to Work?
Once patients receive Masseter Botox, they will likely be curious about how quickly they will see results. To provide a clear and well-defined idea about what they can expect in the days, weeks and months following treatment, here is our results timeline:
- Days 1 to 7: Throughout the first week of post-treatment, patients can expect an initial softening of the masseter muscles, and those with pain or soreness will get fast-acting functional relief.
- Weeks 2 to 4: For the following weeks, the Botox will begin taking effect across the muscles, providing optimal relaxation.
- Months 1 to 2: With time, the relaxed muscles will appear visually slimmer as they undergo disuse atrophy. The other muscles will become more prominent as a result, emphasising a defined jawline.
Practitioners are advised to manage patient expectations following Masseter Botox. While functional relief may be fast-acting, aesthetic results can take time. It is also important to inform patients that the gradual progression of Masseter Botox is beneficial because it allows them to become accustomed to their new facial contours, reducing discomfort.
How Long Does Masseter Botox Last?
In addition to how quickly Masseter Botox takes to work, patients must also be made aware of how long their results will last.
Due to the large size and density of the masseter muscle, Botox results typically last for four to six months. Several factors may influence this duration, including the patient’s metabolism, the dosage, and the severity of the patient’s bruxism.
For the best results, patients may want to consider the ‘Loading Dose’ strategy, whereby they receive treatment every four months for the first year to maintain muscle atrophy before progressing onto a recurring six-month maintenance schedule.
Does Masseter Botox Cause Jowls?
Patients may be concerned that Masseter Botox might cause jowls, so addressing this risk can help ease concern. This sagging of skin around the jaw can occur, though the likelihood of it occurring will depend on a number of factors.
As the structure of the masseter is removed from the jaw, overlying skin can sag, but it’s most likely to occur with older patients and those with pre-existing skin laxity. In order to assess the potential risk for jowls, practitioners should take a patient-by-patient approach.
FAQs: Common Patient Questions
What does the Masseter Botox treatment process look like?
Patients begin with a consultation to review their medical history and facial anatomy. Their face is then cleaned, injection sites are marked, and Botox is applied. The procedure usually takes around 30 minutes.
Does Masseter Botox have any side effects?
Some patients may experience mild swelling, bruising, tenderness, slight pain, or headaches. All side effects tend to be short-term, passing after a few hours.
What should patients do for aftercare?
After treatment, patients should avoid rubbing or touching their face to prevent disturbing the Botox. Alcohol and strenuous exercise should also be avoided to limit bruising and optimise blood flow to the face.
Shop Masseter Botox Treatments with ACRE Pharmacy
Masseter Botox offers patients a simple and effective solution for aesthetic jaw definition and functional pain relief. Providing a slimmer face shape and bruxism relief without the need for surgery, Masseter Botox has lasting results that can enhance patient confidence and comfort.
Discover ACRE Pharmacy’s range of Botox products to treat wrinkles and facial contouring needs. As a trusted UK-based pharmacy, registered with the General Pharmaceutical Council, we offer a vast collection of market-leading aesthetics products. Order online today or contact us for further information.
