Jaw Botox, also called masseter Botox, usually starts relaxing the chewing muscle within 1 to 2 weeks, but visible face slimming typically appears gradually over 4 to 8 weeks as the muscle shrinks. At Re:berry Hongdae, the effect commonly peaks around 2 to 3 months and lasts about 4 to 6 months.
Re:berry Clinic Hongdae · Information reviewed for accuracy · Results vary by individual.
Why does jaw slimming take weeks rather than days?
Botulinum toxin works by blocking the signal from nerve to muscle. That part happens within days, so you may notice chewing feels slightly weaker after a week or two. But the slimmer look depends on the masseter muscle actually shrinking from reduced use, a process called disuse atrophy. Muscle tissue changes gradually, so the visible contour change follows over several weeks. See Jaw Botox (Masseter Reduction).
What does the typical timeline look like?
- Days 1 to 3: Little change; small injection bumps settle within hours.
- Weeks 1 to 2: Chewing tough foods may feel tired; clenching may ease.
- Weeks 4 to 8: The lower face gradually looks narrower, especially from the front.
- Months 2 to 3: Slimming usually reaches its peak.
- Months 4 to 6: Muscle activity slowly returns and the effect fades.
Results vary by individual. People with very large masseters, or those who clench or grind heavily, may see the greatest change but may also need repeat treatment sooner.
Will jaw Botox work if my face is wide for other reasons?
Jaw Botox only slims the part of the width caused by muscle. If your lower face is wide mainly because of bone structure, fat or sagging, the effect will be limited. A doctor can feel the muscle while you clench to judge how much it contributes. Fat-related fullness may respond better to treatments discussed in Square Jaw and Double Chin.
How can I make results last?
Repeating treatment before the muscle fully recovers, often every 4 to 6 months at first, may help maintain the slimmer contour, and some people find they need treatment less often over time. Avoid excessive gum chewing. See How often should I get jaw Botox?
Planning around an event
If you want a slimmer jawline for a wedding or photos, book at least 6 to 8 weeks ahead. Pricing depends on dose and plan and is confirmed in writing at consultation. Request a time via our Booking page.
At a glance
- Muscle relaxing: Often within 3 to 14 days
- Visible slimming: Typically 4 to 8 weeks
- Peak effect: Around 2 to 3 months
- Lasts: About 4 to 6 months, sometimes longer with repeats
- Treatment time: About 10 minutes of injection
Related questions
Can I see jaw Botox results after one week?
Usually not in the mirror. You may feel the muscle weakening when chewing, but visible slimming generally takes four weeks or more because the muscle needs time to shrink. Photos taken before treatment help you compare fairly. Take front-facing photos in the same light before treatment and again after about six to eight weeks to see the change clearly.
Does jaw Botox help teeth grinding?
Relaxing the masseter may reduce the force of clenching and grinding, and some people notice less jaw tension. It does not treat the cause of bruxism, so a dentist's advice and a night guard may still be recommended. Tell your doctor about grinding, as it may affect dosing.
Are there side effects of jaw Botox?
Common effects include temporary tenderness, small bruises and tired chewing. Less commonly, an uneven smile can occur if product spreads to nearby muscles; this usually resolves as it wears off. Some people notice cheek hollowing if dose is high. Report any changes in your smile to the clinic.
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Before you book
This page is general information, not a diagnosis. Suitability, dose, number of sessions and expected results are decided by a doctor at consultation, and results vary by individual. Possible side effects include redness, swelling and bruising. Pricing is confirmed in writing before any treatment. See our medical disclaimer.
Still have a question?
A doctor at Re:berry Clinic Hongdae can answer it for your skin specifically. Multilingual consultation support is available.