Aesthetics

Face Slimming

Our face slimming treatments include masseter reduction to soften a square or bulky jawline and fat-dissolving injections for a double chin, aiming for a more balanced facial contour without surgery.

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Background

Understanding Face Slimming

01
Background

How Did Face Slimming Treatments Develop?

The masseter muscles at the back of the jaw are used for chewing. In some people they become enlarged, for example with teeth grinding or jaw clenching, giving the lower face a square or bulky appearance. Surgical reduction was once the main option; in recent decades, practitioners have increasingly used prescription-only muscle-relaxing injections to reduce the size of the muscle instead.
Fat-dissolving injections developed separately. Injectable formulations containing phosphatidylcholine and deoxycholic acid were first used for localised fat, and later studied in large trials for fat under the chin^[2]. Today these two approaches are often combined to refine the lower face.
Masseterthe chewing muscle at the angle of the jaw
Prescription-onlymuscle-relaxing injections, after assessment
Fat-dissolvinginjections for fat under the chin
Non-surgicalno incisions and usually little downtime
Figure 1. The two main approaches to non-surgical face slimming.
02
Modern Scientific Perspective

How Does Face Slimming Work?

Face slimming at our clinic combines two different mechanisms, depending on what is causing the fullness in your lower face:
Lower-face fullness
muscle or fat?
Masseter reductionA prescription-only medicine relaxes the masseter muscle, which may gradually become smaller over several weeks.
Fat-dissolvingInjected compounds disrupt fat-cell membranes, and the body then clears the released fat over time.
Balanced contourTogether these may give a softer, slimmer-looking jawline.
Figure 2. The two mechanisms used in non-surgical face slimming.
Evidence for masseter reduction is still limited: a Cochrane review found no randomised controlled trials meeting its criteria and called for better-quality studies^[1], although it is widely used in practice. Relaxing the masseter may also ease the strain associated with teeth grinding and jaw clenching in some people. For fat under the chin, a meta-analysis of randomised trials found that deoxycholic acid injections reduced submental fat compared with placebo; side effects were mostly temporary and included pain, bruising, numbness, redness and swelling at the injection site^[2]. Results vary between individuals and usually need more than one session.

References

Fedorowicz Z, van Zuuren EJ, Schoones J. Botulinum toxin for masseter hypertrophy. Cochrane Database of Systematic Reviews. 2013;(9):CD007510. doi.org/10.1002/14651858.CD007510.pub3
Cunha KS, Lima F, Cardoso RM. Efficacy and safety of injectable deoxycholic acid for submental fat reduction: a systematic review and meta-analysis of randomized controlled trials. Expert Review of Clinical Pharmacology. 2021;14(3):383–397. doi.org/10.1080/17512433.2021.1884070

Your session

What you need to know

1Before your treatment

What to Prepare
10 days before:
- Avoid aspirin and other non-steroidal anti-inflammatory drugs (such as ibuprofen), fish oil, ginkgo biloba, St John’s wort and high-dose vitamin E, as these may increase the risk of bleeding and bruising. A regular multivitamin and paracetamol are usually fine if not otherwise contraindicated. Please do not stop any medicine prescribed by your doctor without speaking to them first.
- Tell us if you have a history of cold sores (herpes simplex) on the face.
- Avoid exposure to the sun.
24 hours before:
- Avoid alcohol, as it can increase the risk of bleeding and bruising.
- Avoid waxing, bleaching, tweezing or hair-removal creams on the area to be treated.
- Eat a small meal or snack before your appointment, and avoid hard foods.
Who should not have masseter reduction: this treatment is not suitable if you have myasthenia gravis or another neuromuscular disorder, an allergy to the product or to human albumin, or if you are pregnant or breastfeeding. Please tell us if you are pregnant or breastfeeding, have any allergies (including to soya, as some formulations contain soya-derived phosphatidylcholine), have a bleeding disorder or take blood-thinning medication, have an infection in the area, or have had surgery or other treatment in the area. Your practitioner will check that the treatment is suitable for you.
2During your treatment

What to Expect
- Your practitioner will assess your face to see whether muscle, fat or both are contributing to fullness, and discuss the options and possible side effects with you.
- Prescription-only treatments are given only after a face-to-face consultation with a qualified prescriber.
- The skin is cleansed and the injection points may be marked.
- A small number of injections are given into the masseter muscle and/or the fat under the chin, using a very fine needle.
- Treatment usually takes less than an hour.
3After your treatment

Aftercare
- For facial injections, keep your head upright and avoid touching the treated area for at least 6 hours.
- Avoid heat exposure such as sunbeds and saunas for at least 48 hours.
- Avoid strenuous activity or vigorous exercise for 24 hours.
- Avoid high-pressure activities such as diving and flying for 72 hours.
- Avoid any other facial treatment or massage for 30 days.
- No laser treatment for 2 weeks.
- Use SPF 50 daily.
- Avoid hard foods for at least 5 days.
Mild swelling, tenderness or bruising are common. After fat-dissolving injections, swelling under the chin can be noticeable for a few days. Contact us if you notice difficulty chewing, an uneven smile, or anything that concerns you.

Who can benefit

Who face slimming is for

Face slimming is often chosen by people who would like a softer, more defined lower face without surgery. These are some of the most common reasons our patients ask about it.

Square or bulky jawline

A wide lower face caused by enlarged masseter muscles.

Jaw clenching and teeth grinding

Some people find relaxing the masseter eases clenching; please also see your dentist.

Double chin

Fat under the chin that has not responded to diet and exercise.

Learn more →

Undefined jawline

A jawline that lacks definition, where reducing muscle or fat may sharpen the contour.

Facial balance

People who want a softer, more oval face shape.

Non-surgical preference

People who would prefer to avoid surgery and a long recovery.

Your practitioner will assess whether face slimming is right for you at your consultation. Results vary and are not guaranteed.

FAQ

Frequently asked questions

How do I know whether I need masseter reduction or fat-dissolving?

It depends on what is causing the fullness. A wide, square jaw from enlarged chewing muscles is treated differently from fat under the chin. Your practitioner will assess this at your consultation, and some people benefit from both.

When will I see results?

Masseter reduction usually develops gradually over several weeks as the muscle relaxes. Fat-dissolving results build over a number of weeks and often need more than one session. Results vary from person to person.

Can masseter reduction help with teeth grinding?

Some people find that relaxing the masseter eases jaw clenching and grinding, but this is not guaranteed. If you have jaw pain or grinding, please also speak to your dentist or GP.

What are the possible side effects?

Common side effects include tenderness, bruising and swelling at the injection site. After masseter reduction, some people notice temporary chewing fatigue; rarely, an uneven smile can occur. After fat-dissolving injections, swelling, numbness and firmness under the chin are common and usually temporary.

How long do results last?

Masseter reduction is temporary and usually needs repeating every few months to maintain the effect. Fat cells that have been destroyed do not return, but remaining fat cells can still grow with weight gain.

Still have a question? Ask our practitioners.