Does Chewing Gum Help Your Jawline? What a Trial Found

Chewing gum is unlikely to give you a sharper jawline. In the only randomised trial of gum chewing in healthy adults we found, people who chewed gum three times a day for 6 months got a stronger bite, but their jaw muscle thickness and jaw shape did not change significantly (Jung et al., 2024).

The short version:

• Gum strengthens your bite, not your jaw shape. Bite force was higher by 3 months. Muscle size did not change significantly in 6 months.
• If the muscle does grow, your face gets wider, not sharper. A bigger chewing muscle squares off the lower face at the jaw corners.
• Gum burns almost nothing. About 2 calories for 10 minutes, so it cannot remove the fat that hides a jaw or a double chin.
• Hard gum, mastic and Falim add load and risk, not proven results. Jaw pain, clicking with pain and headaches are reasons to stop.
• What decides how defined your jaw looks: head position, puffiness, body fat and bone. The first three can change; gum touches none of them.

What chewing gum does to your jaw muscles

Your main chewing muscle is the masseter. It runs from your cheekbone to the corner of your jaw. Clench your teeth and press your fingertips on your cheek about a finger-width above and in front of the angle of your jaw: the muscle that hardens is the masseter. It sits at the back corner of the jaw, not along the line from ear to chin.

The idea behind "jawline gum" is that chewing trains this muscle until it grows. Here is what the human studies found:

Study	Who and what	What changed
Jung et al., 2024, randomised trial	58 healthy adults. One group chewed sugar-free gum 3 times a day for 6 months; the other did not.	Maximum bite force was higher by 3 months, which the authors linked to a larger contact area between the teeth. No significant change in masseter thickness or jaw-bone shape.
Kim et al., 2020, randomised trial	40 adults aged 65 or older. A chewing-exercise device, 20 minutes a day, 5 days a week, for 6 weeks.	Bite force and masseter thickness both rose compared with the control group.
Dogan and Sahin, 2026, ultrasound study	25 people who chew mostly on one side.	The masseter on the chewing side was about 1 mm thicker at rest (12.2 vs 11.3 mm).
Levine et al., 1999, lab report	7 adults chewing calorie-free gum.	Energy use rose by about 11 calories an hour.

Muscle growth is possible with training: older adults using a purpose-built device gained thickness, and habitual one-sided chewers have a slightly thicker muscle on that side. But in healthy adults chewing ordinary gum, the one controlled trial found a stronger bite and no measurable change in size. A small trial cannot rule out a small effect. It gives no reason to expect a visible one.

Why jawline gum videos look convincing

A clenched masseter is thicker than a relaxed one. In an ultrasound study of 96 people with jaw-joint problems, the muscle measured about 11 mm at rest and 14 mm while clenching (Lee et al., 2024). Film yourself with your teeth clenched and your jaw corners look fuller than they do at rest.

Camera distance does the rest. In a Rutgers model, a phone held about 12 inches from your face made the base of the nose look about 30% wider than a photo taken from 5 feet (Rutgers). Change the distance, the angle, the light or the clench between two photos, and you get a "before and after" without any change in the face.

Does chewing gum make your face wider?

It can, if the muscle grows, and that is not the same as a sharper jaw. An enlarged masseter gives what doctors call a square face. Its cause is usually unknown, but some authors link it to a gum-chewing habit (Benign masseter muscle hypertrophy, 2008). The reverse also works: clinics inject botulinum toxin into the masseter to shrink it, and a review of 20 publications found that this narrows the lower face (Ghatge et al., 2023).

You can see the difference in our face shape detector. It measures jaw width as a share of cheek width. Its typical oval face has a jaw at 78% of cheek width; its typical square face has a jaw at 85%. More masseter moves you toward square. It does not add the clean line from ear to chin that most people mean by "defined", because that line depends on how much soft tissue covers the bone.

A wider jaw is not scored as better, either. In the LooksLab attractiveness test, jaw proportion is 5% of the men's formula, and it rewards a jaw close to the average proportion, not the widest jaw. Facial fat carries 15% of the men's formula, three times the weight of jaw proportion (20% for women, whose formula has no jaw factor). A photo cannot measure fat, so the test leaves that factor out instead of guessing. Its result is an app estimate from one photo, not a verdict on your face.

Can chewing gum burn face fat or fix a double chin?

No. Two numbers show why:

• Calories. Chewing gum raised energy use by about 11 calories an hour (Levine et al., 1999). Ten minutes a day is about 2 calories. Over a full year that is about 670 calories, less than a large meal.
• No spot reduction. Working a muscle does not burn the fat on top of it. In one trial, ab exercises 5 days a week for 6 weeks did not reduce belly fat (Vispute et al., 2011). We found no study of spot fat loss in the face, and there is no reason to expect the jaw to work differently.

Fat under the chin and along the jaw goes down when your overall body fat goes down, and it matters for how a face reads: how heavy a face looks predicts how healthy and attractive people rate it (Coetzee et al., 2009). Our guide on how to lose face fat shows how much weight it takes before the face changes.

Jawline gum, mastic gum and Falim: is harder gum better?

Products sold as "jawline gum" or "mewing gum", mastic resin and Falim are all harder or longer-lasting than ordinary gum. They make your jaw muscles work harder per minute. As far as we found, that is the main difference.

No trial we found tested any of them for jawline appearance in adults. Gum brands that argue for hard gum lean on indirect evidence, such as a 1987 pilot study of chewing training in children with long faces (Ingervall and Bitsanis, 1987), people who grind their teeth, and animal studies. None of that shows a sharper jaw from chewing in grown adults.

What harder and longer chewing does add is load on the jaw joint. In a study of 200 teenagers, clicking and jaw pain were more common in those who chewed gum 30 to 120 minutes a day than in those who did not (Tabrizi et al., 2014). In 30 children and teenagers (median age 16) with chronic headaches and a heavy daily gum habit, 26 improved after they stopped, and all 20 who started again had their headaches return within days (Watemberg et al., 2014). Neither study proves cause, but both point the same way.

Stop chewing and see a dentist if you have: pain in your jaw muscles or jaw joint, pain that spreads to your face or neck, a stiff jaw, a jaw that locks or will not open fully, painful clicking or grating, or a change in how your teeth fit together. These can be signs of a jaw-joint disorder, and the NIDCR lists cutting down on gum chewing as a self-care step (NIDCR). Clicking without pain is common and usually not a problem. If you clench or grind your teeth, or have crowns, large fillings or braces, ask your dentist before chewing hard gum.

Does chewing on one side make your face uneven?

Probably not in a way you can see. People who chew mostly on one side do have a slightly thicker masseter on that side, about 1 mm in the study above (Dogan and Sahin, 2026), but that study did not measure the face, and we found no good evidence that one-sided chewing makes a face visibly uneven.

Most faces are a little uneven anyway. Before you blame your chewing side, measure it: the face symmetry test compares the left and right sides of your face region by region, including the mouth and jaw corners. A turned head or side light causes more apparent unevenness than a millimetre of muscle.

What is hiding your jawline? A quick self-check

Take a front photo and a side photo in the same place and light, camera at eye level, jaw relaxed and teeth apart (how to take comparable photos). Then go through this table.

Factor	Quick check	Can you change it?	What to do
Body fat	Soft tissue under the chin and along the jaw in the side photo, head level	Yes, over weeks to months	Lower overall body fat with habits you can keep. Gum does not do this.
Head position	Does the line from chin to neck soften when your head drifts forward or your chin drops?	Yes, right away	Keep your head stacked over your shoulders, in daily life and in photos.
Puffiness	Does your face look fuller in the morning, or after salty food, alcohol or short sleep?	Yes, day to day	Compare photos from several days before you judge your jaw.
Photo setup	Phone close, head tilted, light from one side, jaw clenched	Yes, right now	Fix the setup first, or you compare photos instead of faces.
Masseter size	Feel the jaw corners at rest and when you clench	A little, slowly	Bigger means wider, not sharper. Gum is the smallest lever on this list.
Bone and bite	Chin projection, jaw angle and jaw length in the side photo	Not with habits	See the next section.

For most people, the first three rows matter far more than the masseter.

When habits cannot change your jawline

Bone, bite and stubborn fat under the chin need a specialist, not a habit. Orthodontists treat teeth and bite alignment, and oral and maxillofacial surgeons do jaw surgery. Dermatologists and facial plastic surgeons offer botulinum toxin to slim a large masseter (Ghatge et al., 2023), an FDA-approved injection for fat under the chin (Shamban, 2016), fillers and chin implants. Ask about risks, cost and how long results last.

Mewing is not a substitute. The American Association of Orthodontists says the evidence for mewing's jawline claims is "as thin as dental floss" (AAO). Our softmaxxing guide explains which non-surgical changes do show in the face.

An 8-week jawline test

If you want to know what changes your jawline, test one thing at a time. Give it 8 weeks: posture shows at once, but if you have fat to lose, at 1–2 lb a week a change others can notice in your face projects to roughly 4 to 10 weeks (our estimate), so a slow result at week 8 is not a failure.

1. Day 1: measure. Take front and side photos with the setup above. Run the front photo through the face shape detector to measure your jaw-to-cheek width and note the number. Write down the time of day.
2. Pick one lever. Choose the row from the self-check table that looked worst. For most people it is body fat or head position.
3. Change nothing else. Same haircut and beard length, same camera setup, same time of day.
4. Weeks 4 and 8: repeat. Retake the photos and run the detector again. Compare the side photos for the chin-to-neck line and the front results for jaw width.
5. Read it carefully. A clearer chin-to-neck line usually comes from posture or less fat. A change in width alone can come from puffiness or the photo setup, so check it on more than one day.

If you want a plan built around the parts of your face that can change, LooksLab scans your face and builds a week-by-week routine, including the jawline, with progress scans along the way. It is for adults 18 and over.

Common questions

How long does it take for gum to change your jawline?

There is no reliable timeline, because the trial found no significant change in muscle size or jaw shape in 6 months. If someone shows a result after a few weeks of chewing, check the clench, the camera and their weight first.

Is chewing gum bad for your teeth?

Sugar-free gum is not, in normal amounts. The American Dental Association says it may help lower cavity risk alongside brushing and cleaning between your teeth, and trials found fewer cavities in people who chewed it for 20 minutes after meals (ADA). Gum with sugar feeds the bacteria that cause decay.

Can too much sugar-free gum upset your stomach?

Yes. Sweeteners such as sorbitol can cause gas, bloating and cramps at about 5 to 20 grams a day and diarrhea above that (Liauw and Saibil, 2019). One stick of a common sugar-free gum holds about 1.25 grams of sorbitol, so a pack a day can pass 20 grams.

Does mewing gum work better?

Not as far as we found. It is harder gum with a looksmaxxing name, so the hard-gum section above applies.

Does chewing gum give you a double chin?

No. Gum does not add fat; a heavy habit may at most widen the jaw corners.

The bottom line

Chewing gum makes your bite stronger. It is not a reliable way to sharpen your jawline, and hard gum adds strain for little return. Put your effort where the change shows: body fat, head position, puffiness and photos you can compare.