Jawline Botox & Masseter Botox: Slimming, Cost & Results 2026
Jawline Botox slims the lower face by shrinking the masseter muscle. Full guide to dosing, cost, results timeline, bruxism relief, and side effects.
Quick Answer
Jawline Botox — also called masseter Botox or jaw-slimming Botox — is the injection of botulinum toxin into the masseter muscle to shrink it over 8-12 weeks, narrowing the lower face and reducing teeth grinding. Standard dosing is 25-50 units per side (50-100 units total), at a typical cost of $600-2,000 per session in the US. Visible slimming begins at week 4-6 and peaks at week 8-12. Results last 4-6 months for cosmetic effect and 3-4 months for bruxism relief, with most patients needing 2-3 initial sessions for full result and maintenance every 6-9 months thereafter.
What Is Jawline Botox?
Jawline Botox — known interchangeably as masseter Botox, jaw-slimming Botox, jaw reduction Botox, face-slimming Botox, or simply botox for the jawline — is an injection of botulinum toxin type A (Botox, Dysport, Xeomin, Jeuveau, or Daxxify) into the masseter muscle. The masseter is the bulky chewing muscle that sits on the side of the lower face, extending from the cheekbone down to the angle of the jaw.
Unlike upper-face Botox, which targets fine lines and wrinkles, jawline Botox reshapes the lower face by reducing muscle bulk. It's used for two distinct goals — often simultaneously:
- Cosmetic jaw slimming — narrowing a wide, square jawline into a softer, more oval or heart-shaped contour.
- Therapeutic bruxism / TMJ management — reducing the force of teeth grinding and clenching to relieve jaw pain, headaches, and dental damage.
What Is the Masseter Muscle?
The masseter is one of the strongest muscles in the human body relative to its size, generating bite forces of 150+ pounds per square inch. It sits along the angle of the jawline, extending from the zygomatic arch (cheekbone) to the lower jaw (mandibular angle).
In some people the masseter becomes hypertrophied — overdeveloped and visibly bulky. The drivers:
- Bruxism (habitual teeth grinding or clenching, often at night)
- Stress-related jaw tension
- Genetics — certain ethnic backgrounds (Korean, Chinese, Japanese, Southeast Asian) are more predisposed to a wider masseter relative to facial proportions
- Chewing habits — frequent gum chewing, very tough foods (squid, jerky, certain raw vegetables)
- TMJ dysfunction — chronic jaw joint issues that lead to compensatory muscle overdevelopment
An enlarged masseter creates a wide, square-shaped jawline. While this can be a desirable aesthetic in some contexts (and is considered attractive in many male presentations), many patients — particularly women — prefer a softer, more tapered lower face.
How Jawline Botox Works
Botox injected into the masseter blocks the nerve signals that tell the muscle to contract. Over the next 8-12 weeks, the muscle is used less and gradually shrinks — a process called disuse atrophy.
This muscle reduction narrows the jawline, transitioning the face from a square or rectangular shape toward a more oval or heart-shaped contour. The effect is both cosmetic and therapeutic: patients who grind their teeth typically experience significant relief from jaw pain, tension headaches, and dental damage, often within 1-2 weeks (before the visible slimming has even started).
The Procedure Step by Step
- Units per side: 25-50 units of Botox/Xeomin/Jeuveau, or proportionally adjusted Dysport/Daxxify
- Total session dose: 50-100 units
- Injection points: 3-5 per side, distributed across the lower two-thirds of the masseter body, avoiding the superficial portions that control facial expression
- Procedure time: 10-15 minutes
- Pain: Minimal — the masseter area is less sensitive than the upper face; topical numbing is usually unnecessary
- Downtime: None — patients return to normal activity immediately
The injector typically asks you to clench your jaw firmly to identify the muscle bulk, marks the safe injection zone, then places injections directly into the thickest part of the muscle. Going too superficial risks affecting the facial expression muscles (zygomaticus, risorius) and producing an asymmetric smile — which is why jawline Botox is one area where injector experience matters significantly.
What Results Look Like
Masseter Botox results unfold differently from upper-face treatments. The mechanism here is muscle atrophy, not relaxation, so the visible change takes weeks to develop.
Timeline
| Time post-injection | What you'll experience |
|---|---|
| Day 1-3 | No change yet; possible mild tenderness at injection sites |
| Week 1-2 | Jaw feels less tense; bruxism symptoms improve; chewing tough foods feels slightly more effort; no visible slimming yet |
| Week 3-4 | Tension headaches noticeably reduced; still no visible slimming |
| Week 4-6 | Muscle begins to visibly shrink; jawline starts to look narrower from the front |
| Week 8-12 | Maximum slimming effect achieved; lower face appears noticeably more contoured |
| Month 4-6 | Results stable before the muscle gradually regains size |
| Month 6-9 | Most patients return for retreatment; some can extend to 12 months |
Visible Changes Patients Notice
Before-and-after photos consistently show:
- A narrower jawline when viewed from the front
- A smoother, more tapered transition from ear to chin
- Less angular appearance of the lower face
- Reduced bulging at the jaw angle when clenching
- More balanced face proportions when the upper face is naturally narrow
The degree of slimming depends on how hypertrophied the masseter is to begin with. Patients with significantly enlarged masseters may see a dramatic transformation; those with average-sized muscles will notice subtle narrowing.
Cost of Jawline Botox
Masseter Botox requires more units than upper-face treatments, which drives the per-session cost:
| Total Dose | Estimated US Cost (2026) | Use Case |
|---|---|---|
| 50 units | $600-1,000 | Mild masseter hypertrophy, average build |
| 80 units | $960-1,600 | Moderate hypertrophy |
| 100 units | $1,200-2,000 | Significant hypertrophy or severe bruxism |
While the per-session cost is higher than forehead or crow's-feet Botox, jawline Botox typically lasts longer (4-6 months for cosmetic effect, 3-4 months for bruxism relief vs 3-4 months for upper-face Botox). Many patients need progressively fewer units with repeated treatments as the muscle stays smaller between sessions.
For a full breakdown of how Botox is priced per unit and what affects total cost, see our Botox cost guide. For comparison with other lower-face slimming options, see non-surgical jaw contouring and chin filler for jawline definition.
Therapeutic Benefits Beyond Aesthetics
Many patients originally seek jawline Botox for medical rather than cosmetic reasons:
Bruxism relief. Teeth grinding can cause severe dental damage, jaw pain, and morning headaches. Masseter Botox reduces grinding force by 30-40%, protecting teeth and alleviating pain. Most patients with sleep bruxism notice fewer morning headaches within 2 weeks.
TMJ symptom management. Temporomandibular joint dysfunction often involves masseter tension as a contributing factor. Reducing muscle activity can ease jaw clicking, locking, and soreness. Best for muscular-pattern TMJ; less effective for joint-pattern TMJ (disc displacement).
Tension headache reduction. Chronic jaw clenching is a common trigger for tension-type headaches. Many patients report a significant decrease in headache frequency and intensity after treatment — often this is the most life-changing effect.
Dental protection. Bruxism cracks teeth, damages crowns and veneers, and wears down enamel. Reducing the clenching force preserves dental work.
Some insurance plans cover masseter Botox when prescribed for bruxism or TMJ dysfunction (CPT 64612 / J0585), though coverage varies widely. Ask your provider about pre-authorisation before assuming the cost will be out-of-pocket.
Side Effects and Risks
Most side effects are mild and resolve within days to weeks.
Common (>5% of patients)
- Mild bruising at injection sites
- Tenderness for 1-3 days
- Slightly more fatigue when chewing tough foods (steak, jerky, hard bread) for 2-4 weeks
- Subtle "smile asymmetry" if injections placed too superficial — usually resolves as Botox wears off
Less common (1-5%)
- Excessive jaw weakness — over-treatment can make eating less comfortable
- Sunken cheek appearance if too much volume is removed without the patient realising
- Paradoxical bulge of remaining muscle on chewing (rare; resolves after retreatment)
Rare (<1%)
- Permanent smile asymmetry — almost always from poor injection technique
- Allergic reaction to the toxin (extremely rare)
How to minimise risk
- Choose a board-certified dermatologist, plastic surgeon, or oral-maxillofacial surgeon experienced specifically in lower-face Botox
- Ask how many masseter sessions they perform per month (high volume = better outcomes)
- Start conservative — easier to add at follow-up than reverse over-treatment
- Avoid weekend "Botox parties" or unlicensed providers
Important Considerations
Bone Structure vs Muscle
Jawline Botox only reduces muscle bulk. It does not change bone structure. If your wide jawline is primarily skeletal rather than muscular, Botox will have limited effect. Your injector should palpate the masseter while you clench to determine how much of the jawline width is attributable to muscle versus bone. If the answer is "mostly bone", surgical options or jawline contouring filler are more appropriate.
Facial Balance
If the masseter is treated too aggressively, the lower face can appear overly narrow relative to the upper face — what's sometimes called the "alien" or "elf" look. A skilled injector considers your overall facial proportions (cheekbone width, forehead size, chin shape) when determining the appropriate degree of slimming.
Cheek Hollowing
In thin faces, aggressive masseter shrinkage can reveal more of the underlying buccal fat, making the cheeks look slightly hollow. This is uncommon at conservative doses but possible at maximal doses in lean patients.
Chewing Adaptation
Most patients notice slightly more effort chewing tough foods for 2-4 weeks after the first session. Normal eating is unaffected. The sensation diminishes as the body adapts.
How Many Treatments Are Needed?
Most patients need 2-3 initial treatments spaced 4-6 months apart to achieve their desired result. After that, maintenance treatments are typically needed every 6-9 months, often at a reduced dose.
With consistent treatment:
- The muscle atrophies progressively with each session
- Less product is needed over time
- Some long-term patients can extend their treatment interval to once per year
- The improvement plateaus around session 3-4
Botox vs Filler vs Surgery for Jawline
| Approach | What it does | Who it's for | Duration | Cost (US) |
|---|---|---|---|---|
| Jawline Botox (masseter) | Slims wide jawline by shrinking muscle | Hypertrophic masseter, bruxism | 4-6 months | $600-2,000/session |
| Chin filler / jawline filler | Adds definition, sharpens contour | Weak chin, undefined jawline | 12-18 months | $800-2,500/session |
| Combined Botox + filler | Slims wide muscle + adds contour definition | Most ideal-result patients | Varies | $1,500-4,000 |
| Genioplasty / mandibular contouring (surgery) | Permanent bone reshaping | Skeletal asymmetry, large bony jaw | Permanent | $5,000-15,000 |
| HIFU / Ultherapy / Sofwave | Tightens skin envelope | Skin laxity, not muscle bulk | 12-18 months | $1,500-4,500 |
For most cosmetic patients with a wide muscular jawline, jawline Botox is the lowest-risk, highest-satisfaction option. Adding chin filler often delivers the most balanced result.
Frequently Asked Questions
What is jawline botox?
Jawline botox — also called masseter botox or jaw-slimming botox — is the injection of botulinum toxin into the masseter (chewing) muscle on each side of the lower face. Over 8-12 weeks the muscle shrinks from disuse, narrowing the jawline and producing a softer, more oval-shaped lower face. It also significantly reduces teeth grinding and tension headaches.
How does botox jawline slimming work?
Botox blocks the nerve signal that tells the masseter to contract. With less contraction over weeks, the muscle atrophies (shrinks from disuse), reducing its visible bulk along the angle of the jaw. The result is a narrower jawline visible from the front and a smoother contour from ear to chin.
How many units of botox for the jawline?
Standard dosing is 25-50 units per side, for a total of 50-100 units per session. Mild hypertrophy or first-time treatment usually starts at 25 units per side; significant hypertrophy or severe bruxism uses 40-50 per side. Underdosing simply produces less slimming; overdosing risks excessive jaw weakness and chewing fatigue.
How much does jawline botox cost?
In the US (2026), expect $600-1,000 for 50 total units, $1,000-1,600 for 80 units, and $1,200-2,000 for a full 100-unit session. Cost varies significantly by city — major coastal metros run 30-50% higher than the national average. Most providers price at $12-20 per unit for masseter, slightly higher than per-unit rates for upper-face treatment.
Does masseter botox actually slim the face?
Yes — for patients whose jawline width is primarily caused by an enlarged masseter muscle, masseter botox produces measurable, photographically visible slimming over 8-12 weeks. For patients whose wide jawline is primarily skeletal (bony), the effect is minimal — the muscle slimming doesn't change bone structure.
How long does jaw botox last?
Cosmetic slimming lasts 4-6 months before the muscle gradually regains size. Bruxism relief typically lasts 3-4 months. With repeated treatments every 6-9 months, the muscle stays progressively smaller between sessions, and many long-term patients can extend the interval to 9-12 months.
Will my face look too thin after masseter botox?
Not at standard doses. A skilled injector customises the dose to your facial proportions — over-treatment that produces an excessively narrow lower face is a sign of inexperience, not a feature of the treatment. Start conservative with 25 units per side, then add at the follow-up if you want more slimming.
Can men get jawline botox?
Absolutely. Many men get masseter botox for bruxism and TMJ relief without seeking cosmetic slimming, and a smaller subset of men also prefer a less angular jaw. Men typically need slightly higher unit doses (often 40-60 per side) due to larger baseline muscle mass.
Does botox in the jawline help with teeth grinding?
Yes — masseter botox reduces grinding force by 30-40% and is one of the most effective treatments for sleep bruxism. Most patients with grinding-related morning headaches notice improvement within 2 weeks, often before any cosmetic slimming becomes visible.
Is masseter botox safe?
Yes when performed by an experienced injector. Common side effects are mild (bruising, brief chewing fatigue, transient tenderness) and resolve within days to weeks. The most important risk to manage is incorrect injection depth — too superficial can affect the facial-expression muscles and produce smile asymmetry. Choose a board-certified dermatologist, plastic surgeon, or experienced oral-maxillofacial surgeon.
Does jaw botox change your bite?
It reduces the force of your bite slightly but does not change dental alignment, occlusion, or bite pattern. Most patients don't notice any functional difference for normal eating; only chewing very tough foods (steak, jerky, hard bread) feels slightly more effort for the first 2-4 weeks.
Can botox reduce a square jaw?
Yes — if the squareness is caused by an enlarged masseter muscle. Masseter botox is the primary non-surgical treatment for a square or rectangular jawline driven by muscle hypertrophy. If the squareness is bony (skeletal), botox will have little effect and surgical options (genioplasty, mandibular contouring) are more appropriate.
How do I know if my jaw width is from muscle or bone?
Clench your jaw firmly and feel the sides with your fingertips. If you notice a significant bulge that pops outward when you clench (and disappears when you relax), that's masseter muscle — botox will work well. If the width is the same whether you're clenching or relaxed, it's bone — botox won't change it.
Is jeuveau or dysport the same as botox for the jawline?
Yes — Jeuveau, Dysport, Xeomin, and Daxxify all work by the same mechanism (botulinum toxin type A) and can all be used for masseter slimming. Dysport spreads slightly more than Botox, which some injectors prefer or avoid for masseter depending on technique. Daxxify lasts longer (6+ months for some patients) but is more expensive per session. The choice is usually less important than the injector's skill.
How long does it take to see results from jaw slimming botox?
Bruxism relief: 1-2 weeks. Subtle visible slimming: 4-6 weeks. Full visible slimming: 8-12 weeks. Patience is essential — masseter botox is one of the slowest-developing botox treatments, because the cosmetic result depends on muscle atrophy, not relaxation.
Can I combine jawline botox with chin filler?
Yes — and the combination produces some of the most natural-looking lower-face transformation. Botox slims the wide masseter; chin filler adds definition and projection. Most cosmetic injectors recommend doing them in the same visit or 2 weeks apart. See our chin filler for jawline definition guide.
The Bottom Line
Jawline botox sits at the intersection of cosmetic enhancement and therapeutic relief. Whether your goal is a slimmer, more tapered jawline, relief from teeth grinding, or both, it delivers meaningful, predictable results through a 10-15 minute injection with no downtime. The cosmetic effect is gradual — peak slimming takes 8-12 weeks — but the bruxism relief is often noticed within 2 weeks. Find an injector experienced specifically with lower-face anatomy, start with a conservative dose, and plan for 2-3 sessions to reach your end-state result.
