Masseter Reduction

Hypertrophy (increased size) of the masseter muscle can be treated with anti-wrinkle injections. This is often sought out by those wanting to achieve facial slimming or jawline slimming. Slimming the jawline can help to convert a square-shaped face into a more slim, contoured aesthetic which is usually considered a more youthful and attractive facial shape.

Anti-wrinkle injections relax the masseter muscle, reducing the appearance of its size and therefore slimming the jawline and the face. The procedure takes just minutes to complete.

The benefits of the treatment are seen after approximately 7 days and last anywhere between 4-8 months.

Benefits of masseter reduction with botulinum toxin:

– Management of teeth grinding
– Relief from jaw-related headaches
– Jaw-line & facial slimming
– Non-surgical facial contouring

What is Bruxism?

Bruxism is a condition characterised by teeth grinding and excessive clenching of the jaw. Bruxism usually occurs at night during sleep and can blunt the teeth, cause headaches, temporomandibular joint (TMJ) problems, and increases the size of the masseter muscles at the side of the face.

This results in a widening of the jawline and a square appearance of the face. A square jaw is usually seen as a masculine feature and may not be desirable to some people, especially females. Prominent masseter muscles are not always caused by bruxism as it can also be caused by a genetic feature of the face, but both causes are treatable.


Prior to the treatment, you will have a consultation with one of our clinical pharmacists to discuss your goals and to assess the jaw and face as a whole to determine how many injections to give.

Depending on the size of the masseter muscles, multiple treatments may be required to obtain the desired reduction in size. These initial treatments are recommended to take place 8 weeks apart from each other. Depending on the individual and the cause of the condition, the result could last permanently. However, some will require pretreatment should the size begin to return.

Receiving Treatment:

The procedure itself will last approximately 5 minutes. The clinical will clean the injection site and possible apply some local anaesthetic cream if requested. The Treatment normally requires between 4-6 injections on each side of the jaw.

After treatment:

Immediately after: Massester treatment required no recovery time post-injection so you can return to your usual activities as normal. It is common for patients to get a light headache after the procedure which normally subsides within a few hours. Some simple over-the-counter painkillers like paracetamol or ibuprofen can be used.

7-10 days: You will start to notice a reduction in the size of the masseter muscles after about a week. Be patient though as the best is yet to come.

8 weeks (follow-up consultation): At this stage, you will have noticed how much the masseter muscle has reduced, so we can assess the new size of the muscle and re-administer the treatment to reduce it even further.

3-4 months after final treatment: You will now be able to see your final result from the treatment, which will hopefully last permanently depending on the cause of your increased masseter muscles. If you know that the cause was due to teeth grinding, it is recommended to see your dentist obtain a personalised guard to wear at night, as this will reduce the likelihood of the muscles regaining size.

Why choose Evermore?

We have a team of exceptional clinicians with extensive experience in facial rejuvenation treatments. Our team is all qualified medical professionals. This means that we are able to use the consultation to effectively customise each procedure to your needs. We ensure that we consider all available options to you whilst also considering all other medical implications and needs that you may have.

Our team truly believes that everyone is unique and therefore we cannot use a one size fits all approach, especially when it comes to your appearance. We will always make sure that every treatment is personalised to your needs, and you will receive the correct treatment for you, rather than following a standard model for everyone.

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In rare cases patients may experience unwanted short term side effects such as allergic reactions, swelling, headaches, dry eyes, and dry mouth. Nonetheless, botulinum toxin has been deemed as a safe medical product for over 25 years and is most safe when administered by a qualified medical professional.

In the United Kingdom there are three brands of botulinum toxin in circulation. The most commonly known is Botox, and as this was the original product this is how botulinum toxin is commonly referred. The other two brands are Azzalure and Boccature. All three brands provide natural looking, successful results, meaning that no brand is better than another and you can have confidence in whichever is used in your treatment.

This depends on the individual and will be assessed in your initial consultation.

Candidates should be physically healthy adults. You should also have no neuromuscular diseases or major health conditions, and should not be pregnant or breastfeeding. Any queries you may have can be discussed in your consultation.