How Long Masseter Botox Typically Lasts
Masseter Botox continues to rise in popularity across North America as more individuals explore non-surgical options for jawline contouring, clenching relief, and facial balancing. One of the most common questions relates to how long results last—and how the experience unfolds over time.
Below is a clear breakdown of the typical duration, week-by-week expectations, and how the treatment supports both jaw relaxation and facial slimming.
Most masseter treatments last 3–4 months, with some extending up to 5–6 months depending on muscle strength, anatomy, and clenching intensity. Because masseter muscles are among the strongest in the face, the longevity can differ slightly compared to treatments for expression lines.
Consistency also matters; individuals who maintain a regular schedule often experience longer-lasting softening between visits.
Why Masseter Botox Lasts This Long
Masseter injections target the muscles responsible for chewing and involuntary clenching. These muscles are large, dense, and highly active. Botox gradually reduces their activity, giving the jaw area time to relax and soften in appearance. As activity decreases, the outer contour of the lower face may appear slimmer over several weeks.
Longevity depends on:
- baseline muscle strength
- clenching or grinding habits
- metabolic rate
- dosage based on anatomy
- interval between treatments
All these factors influence how quickly nerve activity resumes and how long results remain visible.
Masseter Botox Timeline: Weeks 1–12
Jawline slimming typically becomes visible after the first month, as the muscle begins to reduce in size from decreased activity.
Timeframe | What Typically Happens |
Week 1 | Early reduction in clenching force; no visible slimming yet |
Weeks 2–3 | Noticeable softening when chewing; tension begins decreasing |
Weeks 4–6 | Visible contour changes begin; face appears softer and less square |
Weeks 8–10 | Peak results; jawline looks more refined and masseters feel relaxed |
Weeks 10–12 | Gradual return of movement begins; results remain visible |
Months 3–4 | Most of the effect remains, though movement slowly increases |
Months 4–6 | Full activity returns; ideal timing for retreatment |
Does Masseter Botox Slim the Face?
While the primary goal for many is tension relief, a refined facial contour can also occur. Slimming happens when:
- the masseter muscle decreases in size
- bite force decreases
- habitual clenching reduces
This creates a softer angle from ear to jawline and is especially effective for naturally square or wide lower-face shapes. Slimming is gradual and subtle—never sharp or hollow—when performed within physician-directed clinical guidelines.
What Influences How Long It Lasts?
Muscle Strength
Strong masseters or high clenching intensity often shorten longevity slightly.
Metabolism
A faster metabolism may clear neuromodulators more quickly.
Treatment Consistency
Repeating injections before full return of movement can extend the duration of results over time.
Lifestyle Factors
High stress, gum chewing, and intense jaw engagement may reduce longevity.
Every treatment plan at Skin Vitality is personalized to these variables to maintain balance, comfort, and natural facial proportion.
Safety and Technique Considerations
Masseter injections require precision due to nearby facial structures and the strength of the muscle group. Skin Vitality treatments follow physician-directed clinical protocols overseen by Medical Director Dr. Ramzan, MD. Licensed medical injectors assess muscle thickness, symmetry, bite pattern, and facial contour before establishing a dosing plan. This supports refinement without compromising natural chewing function.
Frequently Asked Questions
How long does masseter Botox last?
Most masseter Botox results last 3–4 months, with peak effects appearing around Weeks 8–10.
When does masseter Botox start slimming the face?
Slimming typically begins developing around Weeks 4–6 as the muscle gradually softens.
Does masseter Botox weaken chewing?
Chewing remains functional; the goal is controlled relaxation, not full muscle inactivity.
Is masseter Botox permanent?
No. Results are temporary and gradually wear off as nerve activity returns.
Does masseter Botox help with jaw clenching or grinding?
Reduced masseter activity often decreases clenching force and may ease jaw-related tension.
At Skin Vitality, we specialize in advanced aesthetics, medical-grade treatments and personalized body contouring plans tailored to your unique body, goals, and lifestyle. With over 200 medically trained staff across 14 clinics, and proudly serving Ontario since 1992, we’re Canada’s #1 provider of Botox®, Juvederm®, and CoolSculpting®, and the leading provider of EMSCULPT NEO in Ontario.
Our treatments are clinically overseen by Dr. Ramzan, MD, Medical Director at Skin Vitality Medical Clinic and a board-certified physician. Treatments are performed by licensed nurses, injectors, and technicians.
We don’t believe in one-size-fits-all treatments, we believe in custom transformations backed by medical expertise, proven technology, and trust.
Joint Council of Cosmetic Practitioners. “Masseter Muscle Hypertrophy and Botulinum Toxin Treatment: A Clinical Overview.”