Magnesium has become a social media sensation. Influencers tout its benefits as a sleep aid, stress reliever, digestion remedy and more, fueling rapid growth in supplement sales. Is it really the cure-all it’s made out to be?

Magnesium is a mineral and electrolyte that plays a key role in more than 300 metabolic reactions in the body. That makes it critical for heart health, blood sugar control, movement and nerve function, among many other processes.

Supplements can help with constipation and are vital for those who are clinically deficient. Some studies suggest magnesium can help with headaches, sleep and other issues, but evidence is limited.

A balanced diet is the best way to get enough magnesium, according to Lauren DeDecker, MD, a Cedars-Sinai internal medicine physician. The mineral is abundant in nuts, seeds, legumes and whole grains, as well as leafy vegetables such as spinach. Other sources include avocados, dark chocolate and fatty fish, such as salmon.

Yet two-thirds of people on a Western diet don’t get enough magnesium through food, DeDecker points out. Excess calcium, alcohol, coffee and ultra-processed foods can depress levels, she noted. Those with poor nutrition, diabetes or digestive ailments such as Crohn’s disease are also likely to have lower levels, as are those taking medications such as diuretics, said Helen Leung, PharmD, a cardiology pharmacist at Cedars-Sinai.

Symptoms of deficiency include muscle spasms and cramps, poor appetite, fatigue, numbness and tingling. Severe cases can lead to abnormal heart rhythm, seizures and cardiac arrest. It’s critical that people who are deficient get more magnesium through their diets or supplements, Leung said.

“I recommend people see a doctor every year to test for magnesium levels in the blood,” she said.

Magnesium effectively relieves constipation and heartburn and is used as a laxative to prep patients for colonoscopies. DeDecker also often recommends it for sleep and relaxation and sees positive results in patients.

“It doesn’t take the place of medication when needed,” she said. “If someone has a mild symptom, it’s a low-risk supplement to try that might be helpful.”

At least one study has found consuming more magnesium is linked to a lower incidence of diabetes and improved fasting glucose levels in diabetic patients. The American Headache Society and American Academy of Neurology state magnesium is “probably” effective in helping to prevent migraines. Other research has suggested magnesium could help with chronic pain and bone density.

DeDecker said doctors often prescribe magnesium for muscle cramps, migraine prevention, mood issues and support with blood pressure and Type 2 diabetes. Still, most health claims require more robust research to back them up, DeDecker said.

“It can be difficult to find high-quality, randomized controlled trials on supplements," she said.

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Patients who want to boost magnesium should begin with dietary changes, Leung said.

“If someone is interested in supplements, they should check with their doctor before starting to make sure it’s safe for them,” she said.

Supplements can interact with some medications, such as antibiotics, thyroid and HIV medications.

Taking the right form of magnesium for your condition is important. Formulations that are poorly absorbed are good for constipation, while those that cross the blood-brain barrier can help with sleep and stress.

• Magnesium citrate: constipation
• Magnesium oxide: constipation
• Magnesium glycinate: sleep and stress 
• Magnesium L-threonate: sleep and stress

Patients experiencing side effects such as diarrhea can switch to a formulation that’s more easily absorbed or an extended-release option, Leung said.

Leung and DeDecker recommend sticking to supplements tested for purity by a third party, such as US Pharmacopeia or NSF International. They also urge moderation.

“Like any supplement, you could take too much, and that could be dangerous,” DeDecker said.

Symptoms of overdose include nausea, vomiting, stomach pain, flushing, low blood pressure, thirst, drowsiness, muscle weakness and slow or shallow breathing. In the worst cases, the heart can stop, leading to coma or death. Those who do not excrete minerals normally—such as people with kidney disease—should be especially cautious, Leung said.

Still, taken under the care of a physician, magnesium could be worth a try for some conditions, DeDecker said.

“It’s generally pretty safe and well-tolerated, and if it’s helpful for symptoms and enables someone to not need or need less of a prescription medication, that’s great,” she said.

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