Jaw slimming is a non-surgical treatment that relaxes the masseter muscle to slim and soften the lower face. Small injections of botulinum toxin reduce an overdeveloped masseter, creating a softer V-line and alleviating jaw clenching. It takes less than 30 minutes with minimal downtime, and the results last about 3 to 6 months. This guide explains how it works and what to expect in Bangkok.

Table of Contents

1. The Short Answer
2. What Is Jaw Slimming and How Does It Work?
3. Who Is It Suitable For?
4. Results, Duration, and Downtime
5. Jaw Slimming vs. Other Face-Slimming Options
6. Jaw Slimming Pricing at Bibi Clinic in Bangkok
7. Frequently Asked Questions

1. The Short Answer

Jaw slimming works by using small injections of botulinum toxin to relax the masseter muscles, the main chewing muscles located on either side of the jaw. In some people, these muscles become enlarged due to genetics, teeth grinding, or frequent chewing, which can make the lower face appear wider.

As the masseter muscles gradually relax over the following weeks, they typically shrink in size, creating a softer and more contoured V-line. Many patients also notice a reduction in jaw tension associated with clenching or grinding. The treatment is temporary, with results that generally last between 3 and 6 months. With ongoing treatment, the muscles may remain smaller for longer periods over time [1][2].

2. What Is Jaw Slimming and How Does It Work?

Jaw slimming is an injection-based treatment that uses botulinum toxin to temporarily relax the masseter muscle. The masseter is a powerful chewing muscle located on either side of the jaw; when it becomes overdeveloped, it can make the lower face appear wider or more square.

Botulinum toxin blocks the nerve signals that cause the muscle to contract, so the muscle becomes less active and gradually loses volume—the jawline takes on a slimmer shape often described as a V-line or ‘small face’ effect [1].

The onset is gradual: the toxin begins to take effect within 2 to 3 days, with Full results will be available in about two weeks. Many patients also notice reduced jaw tension or discomfort from teeth grinding.

The Treatment Process

• Consultation: The doctor evaluates the size of your masseter muscles and your facial structure to determine whether jaw slimming is right for you.
• Preparation: The area is cleaned and, if desired, a numbing cream is applied; most people find the injections tolerable.
• Injection: precise injections into the masseter muscle, usually lasting about 10 minutes
• Aftercare: Resume normal activities immediately; avoid hard chewing, intense jaw exercise, or massaging the area for 24 hours.

Results may vary from person to person.

3. Who Is It Suitable For?

Jaw slimming is most effective for specific concerns, and a consultation is always required first. Good candidates include:

• Masseter hypertrophy — overdeveloped chewing muscles that give the lower face a square or wide appearance
• Bruxism — clenching or grinding that causes jaw pain or headaches
• Those who want a softer, more oval, or V-shaped jawline without surgery

Extra caution may be needed if you are pregnant or breastfeeding, have a neuromuscular condition, or have a known allergy to botulinum toxin products. In addition, if the width of your jaw is primarily due to your bone structure rather than enlarged masseter muscles, the degree of visible slimming may be more limited.

Whether this treatment is right for you, and the appropriate dose to use, should ...must always be determined by a qualified physician following an individual assessment.

4. Results, Duration, and Downtime

You may notice changes within 2 to 14 days, with full results appearing in about two weeks once the masseter muscle has relaxed and slightly reduced in size. Results generally last 3 to 6 months for first-time patients, and with repeated treatments, the muscle may remain smaller for longer periods between sessions as it adapts to reduced activity [2].

There is no significant downtime — Most people resume their daily activities immediately.. Mild redness or tenderness at the injection site may occur, but it usually subsides within a few hours.

Possible side effects

• Temporary mild bruising or swelling at the injection sites
• Short-term jaw stiffness or slight asymmetry (usually resolves on its own)
• In rare cases, difficulty chewing may occur if too much of the product is used—which is why you should choose an experienced doctor

Results may vary from person to person.

5. Jaw Slimming vs. Other Face-Slimming Options

Jaw slimming is one of several ways to contour the lower face. The right option depends on the cause of your concern.

5. Jaw Slimming vs. Other Face-Slimming Options

Jaw slimming is one of several ways to contour the lower face. The right option depends on the cause of your concern.

Combinations are often most effective—for example, pairing jaw slimming with a small amount of chin filler can enhance the V-line. Individual results may vary.

Combinations are often most effective—for example, pairing jaw slimming with a small amount of chin filler can enhance the V-line. Individual results may vary.

6. Jaw Slimming Pricing at Bibi Clinic in Bangkok

The cost of jaw slimming depends on the brand of botulinum toxin and the number of units, which are determined by the size of your masseter muscle and your goals.

The menu below is displayed openly; your exact dose is Confirmed during the consultation; never estimated in advance.

Product / Brand	Units / Area	Price (THB)
Nabota (Korea)	1 area	2,980
Nabota (Korea)	50 units	5,980
Nabota (Korea)	100 units	11,960
Allergan (U.S.)	50 units	16,800
Allergan (U.S.)	100 units	29,800

At Bibi Clinic, treatment is physician-led, featuring a full-face assessment and personalized dosing, as well as support in English, Japanese, and Thai. For the complete, up-to-date menu, see the Anti-Wrinkle Injection Treatment Page.

7. Frequently Asked Questions

Is jaw slimming painful?

Most people describe it as a mild pinch. The needles are very fine and the session is quick, and a topical numbing cream can be applied if desired. Discomfort is generally minimal and short-lived.

How long do results last?

Results typically last 3 to 6 months for first-time patients. With consistent repeat treatments, some find that the effects last slightly longer over time as the muscle gradually loses bulk.

Is there any downtime?

There is no downtime—you can return to work or your daily activities right away. Avoid hard chewing, intense jaw exercises, or touching the injection site for about 24 hours.

Will my face look unnatural or stiff?

When prescribed at the correct dose by an experienced doctor, jaw slimming should look natural. The goal is to slim the lower face, not to immobilize it—you will still be able to chew, speak, and express yourself normally.

Can it be combined with other treatments?

Yes—jaw slimming is often combined with chin or cheek fillers, thread lifts, or skin boosters to achieve a more comprehensive result. Your doctor can advise you on the best combination for your facial structure.

Thinking About Jaw Slimming in Bangkok?

If you are considering jaw slimming in Bangkok, Bibi Clinic offers a personalized consultation with an experienced aesthetic physician—in English, Japanese, or Thai. Book a consultation →

References

[1] The Role of Botulinum Toxin in Masseter Muscle Hypertrophy: A Comprehensive Review. (2025)
Source: PubMed – The Role of Botulinum Toxin in Masseter Muscle Hypertrophy

[2] Efficacy of Botulinum Toxin in Masseter Hypertrophy: A 4-Year Follow-Up Study. (2019)
Source: PubMed – Efficacy of Botulinum Toxin in Masseter Hypertrophy

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Individual results may vary. Please consult a qualified medical professional before undergoing any aesthetic treatment. Bibi Clinic’s physicians will assess your personal suitability during a consultation.