Double Chin (Submental Fullness): Causes, Non-Surgical and Surgical Options, and Which Suits Which Situation?

What is a double chin?

A double chin is a full, rounded or sagging appearance of the area between the tip of the chin and the neck. Seen from the side, the angle between the chin and the neck becomes less defined. In medical terms it is most often not a disease but a feature of appearance, and seeking treatment is a personal choice.

Different structures may lie behind the same appearance. This is why a double chin that looks the same in two people can respond to completely different methods; it cannot be assumed that a method that worked for someone close to you will work for you too.

What causes a double chin?

• Fat accumulation under the skin: thickening of the fat pad under the chin. It becomes more noticeable with weight gain; however, it can also be seen in slim people as an inherited feature.
• Skin laxity: with age, sun damage and after major weight loss, the skin loses its elasticity and sags. In this case the main cause of the fullness is not fat but excess, lax skin.
• Bands in the neck muscle and deep fat: the edges of the thin muscle at the front of the neck (the platysma) can become more prominent with age. Fat lying beneath this muscle cannot be targeted by methods applied through the skin.
• Jaw and neck structure: a small or set-back lower jaw, and a hyoid bone that sits low and forward, make the area under the chin look full even when there is little fat.
• Weight: gaining weight makes a double chin more noticeable; losing weight reduces it in some people, while in others it leaves lax skin behind.
• Age and heredity: a similar appearance under the chin is common among family members.
• Posture: holding the head tilted forwards for long periods makes the appearance temporarily more noticeable; it has not been shown to lead to an irreversible structural change.

During the examination the physician pinches the skin to assess the thickness of the fat, the elasticity of the skin, the muscle bands and the jaw structure. The options are discussed according to this assessment.

When does a double chin suggest another health problem?

Not every fullness under the chin and in the neck is fat or lax skin. Enlargement of the thyroid gland (goitre), enlarged lymph nodes, salivary gland problems and cysts can also cause swelling in this area. The official US prescribing information for deoxycholic acid injection likewise requires other causes, such as thyroid enlargement and enlarged lymph nodes in the neck, to be investigated before treatment.

If there are signs such as unexplained weight gain over a short period, a rounder face or generalised swelling, a general medical assessment is also needed first.

What options are there for a double chin, and which suits which situation?

The methods target two separate problems: those that reduce fat and those that tighten the skin. A method that reduces fat does not tighten lax skin; nor does a method that tightens the skin remove marked fat. A mismatch is the most common cause of disappointment.

What does a fat-dissolving injection (deoxycholic acid) do for a double chin?

Deoxycholic acid is a substance that occurs naturally in bile in the body and disrupts the membrane of fat cells. When it is injected into the fat under the skin beneath the chin, it breaks down the fat cells. The US Food and Drug Administration (FDA) has approved the injection whose active ingredient is deoxycholic acid only in adults, to improve the appearance of moderate or marked fat fullness under the chin; it does not recommend its use in other areas. In a large placebo-controlled trial, an improvement of at least one grade in fullness under the chin was reported in most of those who received the injection; a marked improvement of two grades was seen in fewer people.

The price of this method is a noticeable recovery period. According to the official prescribing information, swelling, bruising, pain and numbness occur in the great majority of those treated; firmness in the area is also common. Less common but important risks are:

• An effect on the nerve branch that moves the lower lip: seen as an asymmetrical smile or facial weakness. In clinical trials it was mostly mild and temporary, and all cases resolved; even so, it should be reported to the physician the same day.
• Difficulty swallowing: reported rarely in trials, and it resolved. This treatment is avoided in people who already have difficulty swallowing.
• Skin ulceration and tissue damage: can develop when the substance is delivered too superficially or affects a blood vessel.
• Nodules and lumps: in 2026 the FDA announced that a warning had been added to the prescribing information about nodules and lumps at the treatment site that may not resolve over time and may require medical intervention.
• Hair loss at the treatment site: may be noticed in the beard area.

The prescribing information states that the treatment should not be given when there is infection in the area, and that in people with marked skin laxity or prominent muscle bands, reduction of the fat may lead to an unwanted appearance. In other words, this method does not tighten lax skin; when the fat decreases, the laxity may become more visible. There are insufficient data on its safety in pregnancy and breastfeeding. Treatments carried out with products of unknown origin or outside a healthcare facility have been associated with serious problems. Which symptoms are expected and which are an emergency is explained in detail in the article “Problems after Fat-Dissolving Injections and Mesotherapy”.

Does cryolipolysis work for a double chin?

Cryolipolysis aims to reduce fat cells over time by cooling fat tissue through the skin in a controlled way. Small applicators have been developed for the area under the chin. In a 60-person study of this area, an average reduction of a few millimetres in fat thickness measured by ultrasound was reported; in other words, the expected change is modest and appears over weeks. The study is small and has no comparison group.

According to the FDA, a temporary change in lip or tongue movements due to an effect on nerves, and a temporary feeling of fullness in the throat, have been reported after treatments under the chin. Fat growing instead of shrinking (paradoxical fat increase) is an uncommon problem that does not resolve on its own and may require surgical correction. Who the method is suitable for is explained in the article “Cryolipolysis (Fat Reduction by Cooling)”, and the possible problems in the article “Problems after Cryolipolysis”.

Do HIFU and radiofrequency tighten a double chin?

These methods aim to stimulate collagen production by heating the skin and the supporting tissue beneath it; their main target is not fat but skin laxity. In mild or moderate laxity they can give modest tightening under the chin and along the jawline; the effect appears slowly and varies from person to person. With marked fat accumulation or marked excess skin they are generally not enough on their own.

For details, see the articles “HIFU (High-Intensity Focused Ultrasound)” and “Radiofrequency Skin Tightening and Radiofrequency Microneedling”; these methods also carry risks such as burns, temporary numbness and, rarely, an effect on nerves.

When is surgery a more realistic option?

Liposuction removes the fat under the chin directly with a thin cannula and generally gives a more marked reduction in fat in a single procedure than non-surgical methods. It is considered in people whose skin is elastic and whose main problem is fat. It is an operation: it carries risks of bruising, swelling, numbness, surface irregularity, bleeding, infection and those related to anaesthesia; it can take months for the swelling to go down completely.

If the skin has become markedly lax, and there are bands and excess skin in the neck, reducing the fat alone does not correct the appearance; it may even make the sagging more visible. In this situation, assessing surgical options such as a neck lift may be a more realistic step than trying one non-surgical session after another. How sagging is graded and when a surgical opinion is worthwhile are explained in the article “Sagging of the Face and Neck”.

A wide or angular lower face can be confused with a double chin. An appearance due to a prominent chewing muscle is a separate subject; see the article “Masseter (Jaw Muscle) Botulinum Toxin”.

Do double chin exercises, massage and straps work?

There is no reliable evidence that jaw and neck exercises, chewing gum, massage devices, firming creams or chin straps reduce the fat under the chin or tighten lax skin. The body does not burn fat selectively from over the muscle being exercised. Straps and massage can make a short-lived difference by temporarily reducing swelling. Fat-dissolving injections sold for use at home, on the other hand, can cause serious harm; do not inject yourself with products of unknown origin.

Realistic expectations

• What determines the result is less the method than matching the method to the right problem: fat, skin or structure.
• With non-surgical methods the change is modest, more than one session is often needed and the result appears over weeks to months.
• No method gives the same result in everyone; the physician cannot predict the result with certainty.
• The effect of methods that reduce fat may diminish if you gain weight; skin laxity continues to progress with age.
• Marked swelling lasting days after an injection is to be expected; if you have an important event, discuss the timing with your physician. The article “Timing Aesthetic Treatments before a Special Event” may offer guidance on this.
• For some people the right decision is to have no procedure at all; a double chin is not a health problem.

Whichever method is being considered, who carries out the treatment and under what conditions directly affects the safety of the outcome. Under the chin, nerves, blood vessels, salivary glands and lymph nodes lie close to one another; it is important that you are assessed in a healthcare facility by a physician who knows the anatomy of this area.