Does magnesium help with teeth grinding?

Maybe your dentist pointed out worn edges on your teeth, or you keep waking up with a jaw that feels like it worked a night shift. Somewhere along the way you read that magnesium relaxes muscles, and a small tablet before bed sounds like a reasonable thing to try.

Plenty of people land on the same idea, so you are in good company. Below I go through what the research says about magnesium and grinding, how much is considered safe, who should leave it alone and which approaches have stronger evidence behind them.

Key takeaways

No completed controlled trial has shown that magnesium reduces teeth grinding. A Cochrane review found insufficient evidence for any medication against sleep bruxism, and magnesium was not among the drugs studied (Macedo et al., 2014). For night-time leg cramps in older adults, magnesium worked about as well as a placebo (Garrison et al., 2020).

• The case for magnesium in bruxism rests on theory, and the only registered trial has not reported results yet.
• If you still want to try it, stay within supplement limits and talk to your doctor first if you have kidney disease.
• Mouth guards protect your teeth, and a 2024 overview of systematic reviews reports positive effects on grinding episodes for biofeedback and physical therapy.

What does the research say about magnesium and teeth grinding?

Direct research is close to non-existent. A 2023 review from Greece describes how low levels of vitamin D, magnesium and omega-3 fatty acids could make the nervous system more sensitive to stress and make nerves and muscles more excitable. The authors then discuss individualised supplementation as a possible help (Pavlou et al., 2023). That is a hypothesis built from biology. I could not find a published controlled study that tested whether taking magnesium leads to less grinding in people.

The closest thing is a small trial registered in Brazil in 2025. It plans to give 30 adults with muscular TMD either 400 mg of magnesium citrate, the muscle relaxant cyclobenzaprine, or both, for seven days. There is no group that gets only a placebo, so even when results arrive, the study cannot tell us whether magnesium beats doing nothing. The registry lists the trial as recruiting, with no results posted (ReBEC, 2025).

Drug treatment for grinding in general has a thin record too. The Cochrane review found only seven eligible trials, each with seven to 16 participants, testing medicines such as amitriptyline, clonidine and propranolol. The results were imprecise and consistent with benefit, no difference or harm (Macedo et al., 2014). A 2024 overview of 31 systematic reviews rated the effects of medication on grinding episodes as inconclusive or negative (Soares-Silva et al., 2024).

Can low magnesium cause teeth grinding?

It has been suggested, but nobody has shown it. The 2023 review lays out a possible pathway from deficiency to higher muscle excitability, without data showing that people who grind are more often low in magnesium (Pavlou et al., 2023).

What systematic reviews do link consistently to bruxism is a different list: alcohol, caffeine, tobacco, some psychiatric medicines, acid reflux and second-hand smoke (Melo et al., 2019). The NHS names stress and anxiety as the most common cause and adds sleep problems such as snoring and sleep apnoea (NHS Teeth grinding, 2026). If stress is the thread you recognise, our article on whether anxiety can cause teeth clenching is worth a read, and if you snore, look at whether sleep apnea can cause teeth grinding.

Does magnesium relax your muscles at all?

This belief sits behind most magnesium advice. The best data come from muscle cramps. A Cochrane review included 11 trials with 735 people. In older adults with night-time leg cramps, magnesium made no meaningful difference to how often cramps happened compared with placebo, and the smaller analyses of cramp intensity and duration found no difference either. The authors concluded that magnesium is unlikely to give older adults clinically meaningful protection from cramps (Garrison et al., 2020). Harvard's nutrition experts reach the same verdict and say the evidence so far does not support magnesium for muscle cramps (Harvard T.H. Chan, 2023).

A cramp in your calf and a clenched jaw at 3 a.m. are different things, so this does not prove magnesium is useless for grinding. It does show that "magnesium relaxes muscles" is weaker than it sounds when it is tested against a placebo.

How much magnesium is safe, and who should avoid it?

In the US, the recommended daily intake for adults is 400 to 420 mg for men and 310 to 320 mg for women, from all sources combined (MedlinePlus, 2025). The tolerable upper limit is 350 mg a day from supplements only. Magnesium from food does not count toward it, because healthy kidneys remove the extra in urine (Harvard T.H. Chan, 2023). The NHS uses a slightly different figure and says 400 mg or less a day from supplements is unlikely to cause harm, while short-term doses above 400 mg can cause diarrhoea (NHS Vitamins and minerals, 2020).

Stomach trouble is the side effect you are most likely to notice. In the cramp trials, oral magnesium mainly caused gastrointestinal effects such as diarrhoea (Garrison et al., 2020). High-dose supplements can also bring nausea and cramping (Harvard T.H. Chan, 2023).

Kidney disease changes the picture. Side effects from high magnesium intake are uncommon except in people with significantly reduced kidney function (MedlinePlus, 2025). Dangerously high blood magnesium usually develops only when people with kidney failure are given Epsom salts or take medicines that contain magnesium, such as some antacids or laxatives. It can cause muscle weakness, low blood pressure and impaired breathing, and in severe cases the heart can stop (MSD Manual, 2025). If you have any kidney condition, speak to your kidney doctor before you start magnesium. If you take regular medication, ask your pharmacist to check it alongside your prescriptions.

What works better than magnesium for teeth grinding?

The 2024 overview of 31 systematic reviews found positive effects on grinding episodes for biofeedback, physical therapy, laser therapy and botulinum toxin. The authors also stress that studies supporting the safe, long-term use of these treatments are still lacking (Soares-Silva et al., 2024). For botulinum toxin, Cleveland Clinic notes that injections usually need repeating every three to four months (Cleveland Clinic, 2023), and our page on masseter Botox goes into the details.

In the moment

For a sore jaw, the NIDCR suggests soft foods, heat or cold on the face together with gentle stretching and strengthening exercises, and cutting back on habits such as clenching and gum chewing (NIDCR, 2026). The NHS adds painkillers such as paracetamol or ibuprofen, or an ice pack wrapped in a tea towel for 20 to 30 minutes (NHS Teeth grinding, 2026).

Long term

A custom mouth guard or splint from your dentist protects your teeth at night (NHS Teeth grinding, 2026). An umbrella review called splints effective for managing bruxism, while a later overview described their effect on grinding episodes as controversial (Melo et al., 2019; Soares-Silva et al., 2024). If a splint is not right for you, our guide to night guard alternatives covers other options. The NIDCR recommends conservative, reversible care such as physical therapy, relaxation, cognitive behavioural therapy and biofeedback, and advises against treatments that permanently change your teeth, bite or jaw joints (NIDCR, 2026). The NHS also suggests relaxation, regular exercise, a regular bedtime, not smoking and not drinking too much alcohol or caffeine (NHS Teeth grinding, 2026).

Try it: the teeth-apart check

Cleveland Clinic describes awake and sleep bruxism as two separate conditions, and notes that you might catch your jaw clenching while you concentrate hard on something (Cleveland Clinic, 2023). This check targets that daytime clenching, and it is the first habit I teach in physiotherapy.

1. Put a few small stickers where your eyes land often, such as the edge of your monitor, your phone case or the bathroom mirror.
2. Whenever you see one, notice whether your back teeth are touching.
3. If they are, let them drift apart. Keep your lips lightly closed and let your tongue rest against the roof of your mouth.
4. Breathe out slowly through your nose and feel your cheeks soften.
5. In the evening, jot down roughly how often you caught yourself clenching and what you were doing at the time.

After a week you will know which moments set you off. Reducing clenching and practising relaxation are part of the self-care the NIDCR recommends (NIDCR, 2026), and this check is an easy way to begin. For more routines, see our TMJ exercises.

How JawBuddy helps

JawBuddy is a digital companion for guided jaw exercises and self-management. JawBuddy Therapy includes a daily tooth contact check, which builds on the same idea as the exercise above.

The app does not replace emergency care or an individual diagnosis from a qualified healthcare professional.

When should you see a doctor?

Emergency: call 999 or 911, or go to A&E if:

• you have kidney disease, have been taking magnesium, Epsom salts or magnesium-containing antacids or laxatives, and you develop breathing problems or severe weakness. Very high blood magnesium can impair breathing and, when severe, stop the heart (MSD Manual, 2025).

Soon: book a dentist or GP appointment if:

• your teeth are worn, damaged or sensitive, or you have pain in your jaw, face or ear, or a partner hears you grinding at night. The NHS advises seeing a dentist (NHS Teeth grinding, 2026).
• you think stress, anxiety, smoking, heavy drinking or drug use is behind your grinding. The NHS suggests your GP for help with these causes (NHS Teeth grinding, 2026).
• your symptoms do not go away or happen more often than not (Cleveland Clinic, 2023).

A tablet is the easy answer, and you have better ones

It makes sense to hope that a supplement could quiet a jaw that works all night. The evidence does not back that up yet, and you still have options with a stronger track record that you can start this week. Begin with the teeth-apart check, ask your dentist about protecting your teeth, and read our overview of teeth grinding for the bigger picture.

For everything else about how jaw problems develop and are treated, our TMJ disorder guide is the best next step.