Jaw Botox is usually only mildly uncomfortable. Each injection feels like a quick sting followed by brief pressure, and the whole treatment takes about 10 minutes. Ice or numbing cream can be used if you are sensitive to needles. The jaw may feel slightly tender for a day, and most people go straight back to work.

When will I see results from masseter Botox?

You will not see a change straight away. Chewing may feel slightly weaker within the first week or two, and the jawline then slims gradually over 2–6 weeks as the muscle shrinks. The result is easiest to judge at about six weeks, so plan treatment well ahead of a wedding or other event.

Can jaw Botox help with teeth grinding or clenching?

It can ease the force of clenching and jaw muscle tension for some people, which is one reason the masseter becomes smaller. It does not cure bruxism or protect your teeth on its own, and its effect on jaw joint (TMJ) disorders is less certain. If you grind at night or have jaw pain, see a dentist as well.

Will jaw Botox affect my smile or chewing?

Chewing may tire more easily with tough or chewy foods for a few weeks, which most people adapt to. Rarely, toxin spreads to the smile muscles in front of the masseter and makes one side of the smile look flatter for several weeks. Careful injection placement lowers this risk, and the effect is temporary.

What happens if I stop jaw Botox?

If you stop, the masseter gradually regains its strength and size over several months, and your jaw returns toward its original shape. It does not rebound to become larger than before. Some people who had several treatments find the muscle stays a little smaller for longer, especially if they also reduce clenching habits.

Can foreigners get jawline Botox in Seoul?

Yes. International patients can have jawline Botox at Hommage Clinic; bring your passport for registration. Walk-ins are welcome, or book ahead for a set time. The injections fit easily into a short trip, but the full result takes up to six weeks to show. Contact us before your visit to arrange language support.

How do I know if my square jaw is muscle or bone?

Place your fingertips on the angle of your jaw and clench. If a firm bulge pushes outward, muscle is a major part of the width and jaw Botox may help. If the width stays the same when you relax and clench, bone or fat may be the main cause. A doctor can confirm this by examining you.

What is paradoxical bulging after masseter Botox?

It is a bulge that appears in part of the masseter when you clench after treatment, usually because a deeper or untreated part of the muscle is still working. In a 2020 Korean study it occurred in one of 20 volunteers and was corrected with a small extra injection. A review at 4–6 weeks lets the doctor check for it.

Can jaw Botox make my cheeks look hollow or saggy?

It can in some faces. If your face is lean or you already have early jowls, reducing muscle bulk can make the area under the cheekbones look hollow or soft tissue look looser. Your doctor may use a lower dose or suggest combining treatment with lifting in these cases.

Can I have jaw Botox and wrinkle Botox on the same day?

Usually yes. Jaw and expression-line treatment use the same type of product in different muscles, and many people have both in one visit. Your doctor will consider the total dose and spacing from any previous treatment. See Botox for wrinkles.

Is there strong scientific evidence for jaw Botox?

The evidence is mostly from case series and small clinical studies, which consistently report a thinner masseter, but high-quality randomized trials are still lacking. A Cochrane review found no trials that met its criteria. That is why results are described as typical ranges rather than guarantees.

Jawline Botox in Seoul | Masseter Reduction

Quick answer

Jawline Botox(masseter reduction) is an injection of botulinum toxin into the chewing muscle at the angle of the jaw. The muscle relaxes and slowly shrinks, so a square jaw looks softer. At Hommage Women's Clinic in Gangnam, Seoul, Dr. Kim Hyunbin plans the dose for each side after a clench test. Injections take about 10 minutes, slimming builds over 2–6 weeks and usually lasts 3–6 months.

Key takeaways

It only helps when a bulky muscle is what makes the jaw wide, not fat, bone or sagging skin.
Nothing changes on the day: the muscle needs weeks to shrink, so judge the result at about six weeks.
Expect chewing to tire more easily on tough foods for a few weeks.
Placement matters: injecting the lower, back part of the muscle avoids the smile muscles and lowers the chance of uneven bulging.
High-quality trials are still few, so results vary from person to person.

Infographic

Jawline Botox in numbers

~10 min

Injection time

About 30 minutes with consultation and clench test.

2–6 wks

Slimming builds

The jaw outline softens week by week.

3–6 mo

Typical duration

Depends on dose, muscle strength and clenching habits.

~6 wks

Judge the result

Plan treatment well ahead of a wedding or event.

12–18%

Thinner muscle at 1 month

Resting masseter thickness in a 20-person ultrasound study.

≥3 mo

Between sessions

Intervals often lengthen with repeat treatment.

Typical figures for jawline Botox at Hommage Women's Clinic and from Bae et al., Toxins, 2020; your own plan may differ after assessment.

✚ Hommage Women's Clinic · Gangnam, Seoul

Key fact	Details
Treatment time	About 10 minutes of injections; around 30 minutes including consultation
Comfort	A few quick stings from a fine needle; ice or numbing cream on request
Sessions	One session, repeated every 3–6 months; intervals often lengthen over time
Downtime	Minimal; pinpoint bruising is possible and chewing may feel tired for a few weeks
Results visible	Slimming builds gradually over 2–6 weeks
How long results last	Typically about 3–6 months, depending on dose, muscle strength and habits
Performed by	A Hommage Clinic physician; treatment plan reviewed by Dr. Kim Hyunbin

Jawline Botox may suit you if you have

A square or wide jaw angle where the muscle bulges and feels hard when you clench
One jaw muscle visibly larger than the other
Muscles enlarged by daytime clenching or night-time teeth grinding
A wish for gradual, reversible slimming without surgery

Wait or choose another option if you

Are pregnant or breastfeeding
Have myasthenia gravis or another neuromuscular disorder, or a past reaction to botulinum toxin
Have a very lean face or early jowls, where a slimmer jaw can make sagging more visible
Have jaw pain, clicking or locking that a dentist has not yet assessed

What is jawline Botox and how does it work?

Jawline Botox relaxes the masseter muscle so that it shrinks over several weeks and the lower face looks narrower. It is the same botulinum toxin type A used for wrinkle-relaxing Botox , placed deep in the jaw muscle instead of in the expression muscles.

The masseter is the thick muscle you can feel at the back of your jaw when you bite down. Like any muscle, it grows with heavy use, so frequent clenching, grinding or chewing can make it bulky and give the face a square outline. Botulinum toxin blocks the nerve signal that makes the muscle contract. Used less, the muscle gradually loses bulk, much as an arm muscle shrinks in a cast.

In Korea this treatment is often called “square-jaw Botox”. Several botulinum toxin products are licensed by the Ministry of Food and Drug Safety (MFDS), and their units are not interchangeable, so you can ask which product and dose will be used.

Who is jawline Botox for?

Jawline Botox works when an enlarged muscle is what makes your jaw wide. The simple test is to clench your teeth with your fingers on the angle of your jaw: if a firm bulge pushes outward, the muscle is a major factor.

It is less helpful, or not helpful, when the width comes from something else:

Fat: soft fullness in the lower cheeks or jowls does not change with toxin. See fat-dissolving injections .
Bone: a wide or flared jaw angle is bone, which toxin cannot change.
Sagging: loose skin along the jawline needs lifting, such as HIFU facial lifting .

If you are unsure whether muscle or fat is behind your face shape, our face slimming injections guide compares the two.

What happens during treatment, and does it hurt?

Jawline Botox is quick and usually only mildly uncomfortable. The injections take about 10 minutes, and you can return to work straight away.

Your doctor asks about your medical history, medicines, previous toxin treatments and any jaw pain or grinding.
You clench and relax several times while the doctor feels the size and borders of each masseter. Photos are taken from the front and sides.
Safe injection points are marked in the lower, bulkiest part of the muscle, keeping away from the smile muscles in front of it.
A few small doses are placed deep into each muscle with a fine needle. Each feels like a brief sting and pressure. The dose can differ between sides if one muscle is larger.

When will I see results, and how long does jawline Botox last?

Results build gradually over 2–6 weeks and typically last about 3–6 months. You will not see a change immediately, because the muscle needs time to shrink.

In the first week or two you may notice your jaw tiring sooner on tough or chewy food. The outline then softens week by week, and the result is easiest to judge at about six weeks. As nerve signals recover, the muscle slowly regains strength and size unless treatment is repeated.

Repeat sessions are usually spaced at least 3 months apart. With regular treatment, some people find the muscle stays smaller and intervals can lengthen. Very frequent, high-dose treatment may raise the chance of antibodies that make future injections less effective.

Aftercare: stay upright for about 4 hours and do not massage the jaw that day. Avoid saunas, alcohol and intense exercise for about 24 hours, and ask before having facial massage or energy-based treatment on the area in the next two weeks.

Risks and possible side effects

Jawline Botox is a widely used treatment, but it has specific side effects that you should know before you decide. Most are temporary and fade as the toxin wears off.

Common and mild: tenderness, small bumps or pinpoint bruising at injection points, and a mild headache for a day or two.
Chewing fatigue: the jaw may tire with tough foods for a few weeks. Most people adapt quickly.
Smile asymmetry: if toxin spreads to the smile muscles in front of the masseter, one side of your smile can look flatter or uneven for several weeks.
Uneven bulging: an untreated part of the muscle can bulge when you clench, which a small top-up may correct.
Contour changes: in thin or older faces, a slimmer jaw can make the area below the cheekbones look hollow or jowls more visible.
Rare: difficulty swallowing or speaking, allergic reaction, or spread of the toxin effect beyond the treated area.

Seek emergency care straight away if you have difficulty swallowing, speaking or breathing. Contact the clinic if your smile looks uneven, chewing becomes difficult rather than just tiring, or one side still bulges noticeably at four weeks.

Jawline Botox vs other jawline treatments

Jawline Botox narrows a wide jaw caused by muscle; other treatments add definition, length or tightness. Many lower-face plans use more than one.

For a sharper line: RF jawline tightening or threads firm loose skin along the jaw.
For a longer, V-shaped chin: chin filler adds projection and length, which makes the lower face look slimmer from the front.
For bone width: mandibular angle reduction is a jaw surgery performed by plastic or oral and maxillofacial surgeons under general anesthesia. Hommage Clinic does not perform facial bone surgery; our guide to facial bone contouring explains what this surgery involves.

Jawline Botox at Hommage Clinic

Hommage Clinic is a women's health and skin clinic in Gangnam, a short walk from Sinnonhyeon Station, and welcomes walk-ins during opening hours. A doctor examines your jaw while you clench, sets the dose for each side and performs the injections.

Because the clinic also offers lifting with Ulthera Prime and Tune Face (Accent Prime), threads and fillers, jaw slimming can be planned as part of a wider lower-face plan when needed. See ourKorean small face treatmentguide or allskin and aesthetic treatments.

Cost depends on the product, the dose needed for your muscle size and any combined treatments. Cosmetic jaw Botox is not covered by Korea's National Health Insurance, and you receive a written quote before treatment. You canbook a consultationto have your jaw assessed.

Is it muscle?

Square jaw: muscle, fat or bone? Why it matters for jaw Botox

A wide lower face can have three quite different causes, and jaw Botox only treats one of them. A bulky masseter feels firm and pushes outward when you bite down. Soft fullness that does not change when you clench is usually fat. A wide, flared angle that stays the same whether you clench or relax is often bone. Many faces have a mix, which is why Dr. Kim feels the muscle while you clench and relax before suggesting a plan.

Getting this step right avoids disappointment. Toxin cannot reduce fat or bone, and in a lean face, slimming a muscle that was supporting the cheek can make the area below the cheekbone look hollow.

Technique

Where is masseter Botox injected? The safe zone explained

Most of the masseter's bulk sits in its lower, back part, just above the angle of the jaw. Doses are placed deep in this area. The zone is kept below a line from the earlobe to the corner of the mouth and behind the front border of the muscle, because the smile muscles (such as the risorius) lie just in front. Toxin that reaches them can make one side of the smile look flatter for several weeks.

Placement depth also matters. The masseter has internal tendon layers, and a 2020 Korean study found that a dose placed too shallow can leave the deeper part working, which may show as a paradoxical bulge when you clench. In that study, one of 20 volunteers developed this bulge on the side injected without ultrasound guidance, and it was corrected with a small extra injection.

Results

Jaw Botox before and after: a week-by-week timeline

Unlike wrinkle Botox, where you see softer lines within days, masseter reduction is a slow change in muscle size. The muscle first gets weaker, then gradually loses bulk because it is used less. In the first two weeks most people notice only that chewing tough food feels tiring. The outline usually starts to look softer from about week 3 and is easiest to assess at about six weeks.

Because the change is gradual, comparing photos taken in the same light and pose at the start and at six weeks is more reliable than the mirror. The effect then holds for a few months before the muscle slowly regains strength, typically 3–6 months after treatment.

Day 0 About 10 minutes of injections; no visible change yet.

Weeks 1–2 The muscle weakens; tough or chewy food tires the jaw sooner.

Weeks 3–6 The muscle loses bulk and the jaw outline softens.

About week 6 Compare photos; a small top-up is considered if one side still bulges.

Months 3–6 Strength slowly returns; repeat if you wish, at least 3 months apart.

Original illustration by Hommage Women's Clinic, Gangnam, Seoul. Typical timeline; individual response varies.

Clenching and grinding

Masseter Botox for clenching, grinding and jaw tension

Many people who ask for jaw slimming also clench during the day or grind their teeth at night. That habit is often why the muscle became bulky in the first place. Relaxing the masseter can lower the force of clenching and ease muscle tension for some people, which is one reason it may help both shape and comfort.

It is important to be realistic: botulinum toxin does not cure bruxism and does not replace a dental night guard, and evidence for jaw joint (TMJ) disorders is less certain. If you have jaw pain, clicking, locking or worn teeth, a dentist should assess you as well. Dr. Kim asks about these symptoms at your consultation and may suggest seeing a dentist before treatment.

Habits that help the result last

Notice daytime clenching: lips together, teeth apart, tongue resting on the roof of your mouth.
Cut back on very chewy foods and constant gum chewing for the first weeks.
Ask your dentist about a night guard if you grind while asleep.

Do

Stay upright for about 4 hours
Choose softer foods if chewing feels tired
Keep teeth apart when you notice clenching
Take photos at the start and at about 6 weeks
Contact the clinic if your smile looks uneven

Don't

Massage or press on the jaw that day
Use saunas, drink alcohol or train hard for about 24 hours
Chew gum constantly in the first weeks
Have facial massage or energy treatments on the jaw for 2 weeks without asking
Repeat treatment sooner than 3 months

✚ Hommage Women's Clinic · Gangnam, Seoul

Your face shape

V-line jaw Botox: when to combine, and when to go slowly

A V-shaped lower face, popular in Korea, usually depends on more than a slimmer masseter. A short or receding chin, soft tissue along the jawline and early sagging all change how wide the lower face looks from the front. That is why jaw Botox is often planned together with chin filler , RF jawline tightening or a V-line thread lift , and why a full plan is discussed in our Korean small face treatment guide.

Going slowly is wiser in some faces. If your face is already lean, or you are starting to notice jowls, reducing muscle bulk can make the cheek look hollow or let soft tissue sag more visibly. In those cases Dr. Kim may start with a lower dose, treat only the bulkier side, or suggest lifting first.

Evidence

Does jaw Botox work? What the research says

Masseter reduction with botulinum toxin is widely used, especially in East Asia, and many case series and small clinical studies report a thinner muscle and a narrower lower face. The quality of that evidence is limited, though. A Cochrane review that searched for randomized controlled trials on benign masseter hypertrophy found none that met its criteria, and concluded that well-designed trials are still needed. The numbers below come from a small, carefully measured study and should be read as an indication rather than a promise.

12–18%

Thinner masseter at 1 month

Resting thickness by ultrasound; 18% with ultrasound-guided and 12% with standard injection.

Bae et al., Toxins, 2020

~2 mm

Narrower contour

Facial contour per side at 1 month on 3D scanning (about 1.9–2.2 mm).

Bae et al., Toxins, 2020

1 of 20

Paradoxical bulging

Seen on one standard-injection side; corrected with a small extra dose.

Bae et al., Toxins, 2020

0 RCTs

High-quality trials

No randomized trials met criteria in the Cochrane review on masseter hypertrophy.

Cochrane Review CD007510

Limitations. The study above included 20 young Korean volunteers given 24 units of one toxin and followed for a short time; your result may be larger or smaller. Long-term data on repeated treatment are limited. The US BOTOX label carries a boxed warning that toxin effects can rarely spread beyond the injection site and cause swallowing or breathing problems; seek urgent care for any such symptom.

✚ Hommage Women's Clinic · Gangnam, Seoul

Traveling to Seoul

Jaw Botox in Seoul for international patients

The injections fit into a short trip: consultation, clench test and treatment usually happen in one visit of about 30 minutes, with no real downtime. The catch is timing. Because slimming takes up to six weeks, you will usually see the full result after you are home. Hommage Women's Clinic is in Gangnam, a short walk from Sinnonhyeon Station (Line 9 and Shinbundang Line).

Planning your visit

Come early in your stay, so you can return for a check if anything feels unusual in the first days.
Bring your passport, a list of medicines, and the product, dose and date of any previous jaw or face toxin.
Send front and side photos and your questions in advance by WhatsApp, KakaoTalk or the contact form.
Take your own photos on the day, in good light, for a fair comparison at six weeks.

After you fly home

Send six-week photos to the clinic for review. If one side still bulges, a top-up can be done on your next visit or by a doctor at home using the product and dose record you were given. Seek urgent local care for any difficulty swallowing, speaking or breathing.

Your doctor

Dr. Kim Hyunbin

Associate Director · Skin & Aesthetic Treatments

Dr. Kim maps each masseter by touch while you clench and may use a different dose on each side when the muscles are uneven. Dr. Kim keeps injections away from the smile muscles and starts conservatively when the face is lean, so slimming does not make the cheeks look hollow.

Associate director dedicated to skin and aesthetic procedures, with extensive experience in lifting, botulinum toxin, fillers and laser treatments.

Read Dr. Kim Hyunbin's profile →

Does jaw Botox hurt?
Jaw Botox is usually only mildly uncomfortable. Each injection feels like a quick sting followed by brief pressure, and the whole treatment takes about 10 minutes. Ice or numbing cream can be used if you are sensitive to needles. The jaw may feel slightly tender for a day, and most people go straight back to work.
How long does jawline Botox last?
Jawline Botox typically lasts about 3–6 months. The slimming builds over 2–6 weeks, holds for a few months, and then fades slowly as the muscle regains strength. People who clench or grind heavily may find it wears off sooner, while regular repeat treatments can keep the muscle smaller and let intervals lengthen.
When will I see results from masseter Botox?
You will not see a change straight away. Chewing may feel slightly weaker within the first week or two, and the jawline then slims gradually over 2–6 weeks as the muscle shrinks. The result is easiest to judge at about six weeks, so plan treatment well ahead of a wedding or other event.
Can jaw Botox help with teeth grinding or clenching?
It can ease the force of clenching and jaw muscle tension for some people, which is one reason the masseter becomes smaller. It does not cure bruxism or protect your teeth on its own, and its effect on jaw joint (TMJ) disorders is less certain. If you grind at night or have jaw pain, see a dentist as well.
Will jaw Botox affect my smile or chewing?
Chewing may tire more easily with tough or chewy foods for a few weeks, which most people adapt to. Rarely, toxin spreads to the smile muscles in front of the masseter and makes one side of the smile look flatter for several weeks. Careful injection placement lowers this risk, and the effect is temporary.
What happens if I stop jaw Botox?
If you stop, the masseter gradually regains its strength and size over several months, and your jaw returns toward its original shape. It does not rebound to become larger than before. Some people who had several treatments find the muscle stays a little smaller for longer, especially if they also reduce clenching habits.
Can foreigners get jawline Botox in Seoul?
Yes. International patients can have jawline Botox at Hommage Clinic; bring your passport for registration. Walk-ins are welcome, or book ahead for a set time. The injections fit easily into a short trip, but the full result takes up to six weeks to show. Contact us before your visit to arrange language support.
How do I know if my square jaw is muscle or bone?
Place your fingertips on the angle of your jaw and clench. If a firm bulge pushes outward, muscle is a major part of the width and jaw Botox may help. If the width stays the same when you relax and clench, bone or fat may be the main cause. A doctor can confirm this by examining you.
What is paradoxical bulging after masseter Botox?
It is a bulge that appears in part of the masseter when you clench after treatment, usually because a deeper or untreated part of the muscle is still working. In a 2020 Korean study it occurred in one of 20 volunteers and was corrected with a small extra injection. A review at 4–6 weeks lets the doctor check for it.
Can jaw Botox make my cheeks look hollow or saggy?
It can in some faces. If your face is lean or you already have early jowls, reducing muscle bulk can make the area under the cheekbones look hollow or soft tissue look looser. Your doctor may use a lower dose or suggest combining treatment with lifting in these cases.
Can I have jaw Botox and wrinkle Botox on the same day?
Usually yes. Jaw and expression-line treatment use the same type of product in different muscles, and many people have both in one visit. Your doctor will consider the total dose and spacing from any previous treatment. See Botox for wrinkles.
Is there strong scientific evidence for jaw Botox?
The evidence is mostly from case series and small clinical studies, which consistently report a thinner masseter, but high-quality randomized trials are still lacking. A Cochrane review found no trials that met its criteria. That is why results are described as typical ranges rather than guarantees.

References

Sources used for this page, reviewed by Dr. Kim Hyunbin. Read our editorial and medical review policy.

Bae H, Kim J, Seo KK, Hu KS, Kim ST, Kim HJ. Comparison between conventional blind injections and ultrasound-guided injections of botulinum toxin type A into the masseter: a clinical trial. Toxins. 2020;12(9):588. doi:10.3390/toxins12090588.
Botulinum toxin for masseter hypertrophy. Cochrane Database of Systematic Reviews. CD007510, updated review (searches to April 2013). Cochrane Library
Allergan (AbbVie). BOTOX® Cosmetic (onabotulinumtoxinA) prescribing information, boxed warning on distant spread of toxin effect. PDF

This page is general information and does not replace a personal consultation. Illustrations are original works of Hommage Women's Clinic, Gangnam, Seoul; photos marked illustrative are not of patients.

Skin & Aesthetics · Contouring

Jawline Botox in Seoul: Slimming an Enlarged Masseter Muscle

Jawline Botox in numbers

Injection time

Slimming builds

Typical duration

Judge the result

Thinner muscle at 1 month

Between sessions

Jawline Botox at a glance

Jawline Botox may suit you if you have

Wait or choose another option if you

What is jawline Botox and how does it work?

Who is jawline Botox for?

What happens during treatment, and does it hurt?

When will I see results, and how long does jawline Botox last?

Risks and possible side effects

Jawline Botox vs other jawline treatments

Jawline Botox at Hommage Clinic

Is it muscle?

Square jaw: muscle, fat or bone? Why it matters for jaw Botox

Technique

Where is masseter Botox injected? The safe zone explained

Results

Jaw Botox before and after: a week-by-week timeline

Clenching and grinding

Masseter Botox for clenching, grinding and jaw tension

Habits that help the result last

Aftercare

Jaw Botox aftercare: do's and don'ts

Do

Don't

Your face shape

V-line jaw Botox: when to combine, and when to go slowly

Evidence

Does jaw Botox work? What the research says

Thinner masseter at 1 month

Narrower contour

Paradoxical bulging

High-quality trials

Traveling to Seoul

Jaw Botox in Seoul for international patients

Planning your visit

After you fly home

Choosing well

How to choose a clinic for jaw Botox in Seoul

Ask before you book

What affects the cost of jaw Botox in Seoul?

Your visit

What to expect at your jawline Botox appointment

Consultation

Clench test

Injections

Review

Your doctor

Dr. Kim Hyunbin

Jawline Botox: frequently asked questions

Does jaw Botox hurt?

How long does jawline Botox last?

When will I see results from masseter Botox?

Can jaw Botox help with teeth grinding or clenching?

Will jaw Botox affect my smile or chewing?

What happens if I stop jaw Botox?

Can foreigners get jawline Botox in Seoul?

How do I know if my square jaw is muscle or bone?

What is paradoxical bulging after masseter Botox?

Can jaw Botox make my cheeks look hollow or saggy?

Can I have jaw Botox and wrinkle Botox on the same day?

Is there strong scientific evidence for jaw Botox?

References

Related jawline and contouring treatments

Find out whether jaw Botox will slim your face