How Masseter Botox Works
The masseter is the thick, rectangular chewing muscle sitting over the jaw angle on each side of the face. In some people — through genetics, habitual jaw clenching (bruxism), or high-chew diets — this muscle hypertrophies (enlarges), producing a square or wide lower face.
Botulinum toxin type A works by blocking the release of acetylcholine at the neuromuscular junction — the chemical signal that tells a muscle to contract. Injected directly into the masseter, it reduces the muscle’s ability to generate full contractions. Without regular full-force use, the muscle gradually decreases in bulk over 6–8 weeks, narrowing the visible jaw angle.
The procedure takes 10–15 minutes. A practitioner marks injection points bilaterally — typically two to four injection points per side — and delivers the toxin using a fine needle. Topical anaesthetic is optional; most patients describe the sensation as a brief sting.
Units required for visible jaw reduction: 20–30 units per side, or 40–60 units total. Under-dosing — common in budget packages — produces minimal muscular change. The dose is calibrated to masseter volume: larger muscles require the higher end of that range. Patients with severe hypertrophy may require up to 35 units per side for first-session results.
The mechanism is reversible. Nerve terminals regenerate over 4–8 months, acetylcholine transmission resumes, and the muscle regains its capacity for full contraction. Without re-treatment, bulk gradually returns. This is not a flaw in the procedure — it is the pharmacology of botulinum toxin.
Candidacy: Muscular vs Skeletal Jaw Width
The single most important clinical distinction in jaw slimming is the origin of the width: muscular hypertrophy versus skeletal bone width. Botox addresses only muscular bulk. A wide mandible angle — the bone itself — does not respond to botulinum toxin.
How to assess your own jaw type: Clench your back teeth firmly and place your fingers over the jaw angle area below and in front of your ears. If the muscle bulges visibly or you feel it harden significantly, muscular hypertrophy is a likely contributor. If the width is present equally at rest and during clenching, the bone is the primary cause.
A 강남 (Gangnam) clinic consultation will typically include facial photographs at rest and clenching, and may include a lateral cephalometric X-ray (a side-profile skull X-ray) to measure the mandible angle directly. Do not proceed to treatment without understanding which component — muscular, skeletal, or both — is driving your jaw width.
Often a good candidate
- Masseter muscle visibly enlarges or hardens on clenching
- Jaw width is noticeably greater during clenching than at rest
- Diagnosed or suspected bruxism (jaw clenching or teeth grinding)
- Previous Botox responder — you have had prior results that confirmed muscular cause
- Looking for a non-surgical, low-downtime option with gradual, natural-looking change
Should reconsider or wait
- Jaw width present equally at rest and on clenching — may indicate skeletal component requiring imaging to clarify
- Very severe hypertrophy — may require higher units and realistic expectations for first session
- Currently pregnant or breastfeeding — botulinum toxin is contraindicated
- Neuromuscular conditions (e.g., myasthenia gravis) — contraindicated; discuss with physician
Not a suitable candidate
- Jaw width is primarily skeletal (confirmed by X-ray or CT) — Botox will not produce meaningful change; jaw angle reduction surgery is the indicated procedure
- Known hypersensitivity to botulinum toxin or albumin
- Active infection at the planned injection site
Cost in Korea and What’s Included
Three factors set the price of masseter Botox in Korea: clinic tier (location and overhead), units administered, and brand used. Budget clinics outside Gangnam use Korean-brand toxins and offer lower unit counts; premium Gangnam clinics use higher units, may offer international brands, and charge accordingly.
| Tier | Units (total) | KRW per session | USD (approx) | AUD (approx) | Brand typically used |
|---|---|---|---|---|---|
| Budget clinic | 40–50 units | ₩150,000–200,000 | ≈USD$110–147 | ≈AUD$173–230 | Meditoxin, Botulax, or Nabota |
| Mid-tier clinic | 50–60 units | ₩200,000–300,000 | ≈USD$147–221 | ≈AUD$230–345 | Nabota, Botulax, or Dysport |
| Premium Gangnam clinic | 60–70 units | ₩300,000–400,000 | ≈USD$221–295 | ≈AUD$345–460 | Botox (Allergan), Dysport, or Korean brand by request |
What is typically included: the consultation, the injection procedure, and the toxin units quoted. What is typically not included: post-treatment follow-up visits (usually free at most clinics if required within 2 weeks), additional top-up units if the practitioner determines under-dosing at review, or combination treatments such as chin filler.
For international patients combining masseter Botox with a surgical trip, the cost differential versus Western markets is significant — USD$600–1,200+ per session is the common range at US medical spas, making even a premium Korean clinic session a fraction of equivalent pricing abroad.
Results, Longevity, and Re-treatment
First-session results are gradual, not immediate. The toxin requires time to produce muscular atrophy, and patients who expect dramatic change within the first two weeks are likely to be disappointed. The full visible result appears at 6–8 weeks post-injection and is most apparent in photographs comparing the jaw angle before treatment versus at peak effect.
Toxin binds at neuromuscular junction. Injection site tenderness resolves. No visible slimming yet — this is expected.
Masseter bulk begins to reduce as the muscle atrophies from reduced use. Lower face contour narrows noticeably in photographs.
Maximum muscle reduction achieved. Jaw angle is at its slimmest. This is the optimal point for comparison photography.
Nerve terminals regenerate. Muscle begins recovering contractile capacity. Jaw angle may start to widen again, particularly in patients who clench.
Most patients schedule re-treatment at this point to maintain results. Waiting until full muscle recovery resets progress.
With consistent re-treatment every 4–6 months over 2–3 years, the masseter undergoes cumulative atrophy — some long-term patients extend their intervals or find maintenance doses sufficient. However, stopping treatment entirely allows muscle bulk to return over 6–12 months. For patients seeking a permanent outcome, jaw angle reduction surgery (mandible angle osteotomy) — not Botox — is the indicated procedure.
Korean vs International Botulinum Toxin Brands
Korean clinics use a mix of international and domestically manufactured botulinum toxin type A products. International patients should understand which they are receiving and why the distinction matters for expectations and pricing.
International brands available in Korea:
- Botox (Allergan/AbbVie): the reference product; 100-unit vials; widely used at premium clinics
- Dysport (Ipsen): higher unit-to-effect ratio than Botox (≈2.5 Dysport units ≈ 1 Botox unit); used at some mid-tier and premium clinics
- Xeomin (Merz): complexing protein-free formulation; less common in Korea
Korean-manufactured brands:
- Meditoxin (Medytox): one of the first Korean botulinum toxin products; manufactured under MFDS (Ministry of Food and Drug Safety) regulation and approved for cosmetic use in Korea
- Nabota (Daewoong Pharmaceutical): MFDS-approved; the first Korean botulinum toxin to receive FDA approval in the United States (as Jeuveau), though marketed under different labelling
- Botulax (Hugel): MFDS-approved; widely used at budget and mid-tier Korean clinics
Korean-brand toxins are priced significantly lower than Botox and Dysport, which is a primary driver of Korea’s lower per-session costs. Clinical outcomes for jaw slimming are comparable across brands when units are correctly calibrated. The key variable is total units delivered — not brand. Confirm the brand and unit count in writing before any session.
Is masseter Botox permanent in Korea?
Masseter Botox is not permanent. The toxin effect lasts 4–8 months per session. With repeated treatment every 4–6 months over 2–3 years, the masseter gradually atrophies — some long-term patients find results last longer and require less frequent re-treatment. After stopping treatment, the muscle returns to original bulk over 6–12 months. For a permanent result, jaw angle reduction surgery (mandible angle osteotomy) is the only option. Botox is a maintenance treatment, not a permanent solution.
Is Korean Botox (Meditoxin, Nabota) safe?
Meditoxin, Nabota, and Botulax are botulinum toxin type A products manufactured by Korean pharmaceutical companies under MFDS (Ministry of Food and Drug Safety) regulation and approved for cosmetic use in Korea. They are not FDA-approved for use in the United States, which is why they are rarely used internationally outside Korea. For patients treated at Korean clinics, they are licensed for the indication at the point of use. The clinical profile is comparable to Botox and Dysport for cosmetic applications.
Can I combine masseter Botox with surgery on the same Korea trip?
Yes — masseter Botox is often added to rhinoplasty or eyelid surgery trips as a same-day or adjacent-day procedure with no conflict. If you are also planning jaw reduction surgery, discuss timing with your surgeon — some prefer to assess bone-only jaw width before recommending whether Botox is a standalone option or a surgical adjunct. Do not receive Botox into a healing surgical site (e.g., the jaw area post-jaw surgery) without explicit surgeon clearance.