Jaw Slimming (Masseter Botox)

PHP Aesthetic-Wellness

If you wake up with a tight, aching jaw, suffer from headaches that start at your temples, or have noticed your jawline looking wider or more square over time, you may be dealing with bruxism — chronic teeth grinding or clenching, often without realising it.

This repetitive activity causes the masseter muscle (the main chewing muscle, at the back of the jaw) to enlarge through overuse — much like any muscle that's exercised repeatedly. The result is a jawline that appears wider or bulkier than your natural bone structure, alongside symptoms that are often dismissed as unrelated: jaw soreness, headaches, tooth wear, and a tight or clicking jaw joint.

Botox injected into the masseter muscle addresses both sides of this: as the muscle gradually relaxes and reduces in size, the jawline softens into a more oval, refined shape — while reduced clenching force can ease jaw tension, grinding, and associated headaches.

About this treatment

In summary

A consultation is essential first, to assess whether your jawline width is due to muscle (masseter hypertrophy), bone structure, or both — this determines whether this treatment is right for your goals.

Botox injections into the masseter are not painful

Botox injections into the masseter are not painful, and are administered with small, fine needles.
Results are gradual

Results are gradual. The slimming effect typically becomes visible from around 4–6 weeks, with the fullest effect at 8–12 weeks.
Functional symptoms — jaw tension

Functional symptoms — jaw tension, clenching, headaches — often improve within the first 1–2 weeks, ahead of the visible cosmetic change.
Repeat treatments are usually needed every 4–6 months

Repeat treatments are usually needed every 4–6 months to maintain both the slimming effect and symptom relief.

Frequently Asked Questions

IS THIS THE SAME AS BOTOX FOR WRINKLES?

It’s the same product (Botox®/botulinum toxin), used differently. Rather than targeting the small muscles that cause expression lines, this treatment targets the larger chewing muscle at the jaw — addressing both muscle bulk (appearance) and excessive muscle activity (grinding/clenching).

WILL IT AFFECT MY ABILITY TO CHEW OR EAT?

At the correct, carefully assessed dose, normal chewing function is preserved. The treatment reduces *excessive* muscle activity and bulk, not normal day-to-day function. This is why a thorough consultation and assessment is essential before treatment — dosing is tailored to the individual.

HOW LONG UNTIL I SEE RESULTS?

Functional symptoms — jaw tightness, clenching, headaches — often begin to ease within the first one to two weeks. The cosmetic slimming effect is more gradual, as the muscle reduces in size over several weeks; most patients see visible jawline changes from around 4–6 weeks, with full results by around 8–12 weeks.

IS IT SUITABLE FOR EVERYONE WITH A WIDE JAWLINE?

Not necessarily — jawline width can come from the masseter muscle, the underlying jawbone, or both. During your consultation, we’ll assess which factors are contributing to your jawline shape, since this treatment addresses the muscular component specifically. If bone structure is the primary factor, a different approach may be more appropriate, and we’ll discuss this honestly.

IS THERE ANY DOWNTIME?

There is no significant downtime. Some mild tenderness in the jaw area for a day or two is possible, but most patients return to normal activities immediately.

HOW OFTEN DO I NEED TREATMENT?

Most patients require repeat treatment every 4–6 months to maintain both the symptom relief and the slimmer jawline appearance. Some patients find that with repeated treatment over time, the muscle remains smaller even between sessions.

CAN THIS HELP WITH TMJ (JAW JOINT) PAIN?

Many patients with bruxism-related jaw tension also experience discomfort in the jaw joint itself (TMJ). By reducing the clenching force from the masseter, this treatment can contribute to easing TMJ-related discomfort, though a broader assessment may be recommended if TMJ pain is a primary concern.