How magnesium affects your sleep and anxiety

The essential mineral is important for the body—but it doesn’t work miracles. Here’s what the experts say about magnesium’s powers.

If you’re regularly struggling to fall asleep, reaching for magnesium supplements may not give you the relief various articles have been promising—unless it’s specifically mild anxiety that’s keeping you up at night. Then, it might help. But based on research to date, don’t expect much extra shut-eye once you do fall asleep.

Articles about magnesium have been popping up everywhere thanks to a tsunami of TikTok videos promoting the supplement for nearly every ailment imaginable. The hashtag #magnesium has more than 552 million views, and #magnesiumsupplements has more than 35 million, but the claims made in these videos are not always backed by evidence.

Magnesium plays an important role in the body, and getting enough can help with muscle cramps, migraines, blood pressure, osteoporosis, and potentially even lower the risks of bone fractures, heart disease, and stroke. But it’s not a miracle mineral. Its benefits appear modest for anxiety and inadequate for sleep, at least so far.

Magnesium for anxiety?

Magnesium is essential for human health, playing a role in a wide variety of functions, including absorption of vitamin D. Magnesium deficiency is uncommon, though it is more frequent in people with gastrointestinal illnesses, type 2 diabetes, and alcohol dependence. Inadequate amounts may increase the risk of cardiovascular disease and stroke, but it can be hard to determine whether someone is getting enough since blood tests for magnesium don’t accurately reflect how much is actually in the body.

Still, most studies estimate many are falling short of the daily recommended amounts: 310-360 milligrams a day for women and 400-420 mg for men. The richest food sources of magnesium include green leafy vegetables, such as spinach, as well as avocadoes, cocoa (especially dark chocolate), and seeds and nuts—almonds, pumpkin seeds, peanuts, sunflower seeds, cashews, hazelnuts, and even popcorn.

A diet without magnesium-rich foods may be reason to take supplements, but will doing so ease anxiety symptoms? Possibly, if the anxiety is relatively mild according to Gregory Scott Brown, a psychiatrist and author of the The Self-Healing Mind.

“We definitely need more and bigger studies, but there is some evidence that magnesium can help with mild anxiety and even mild forms of depression,” says Brown, an affiliate faculty member at the University of Texas Dell Medical School in Austin. “If someone’s feeling wired and kind of wound up, and they want to try something ‘natural’ or take a supplement, magnesium wouldn’t be a bad place to start.”

A randomised controlled trial in 2017 found that magnesium supplements improved mild depression and anxiety symptoms, building on previous research finding a positive impact on mood. A 2017 systematic review concluded that about half the studies looking at magnesium and anxiety found a positive effect, but the studies were poor quality. A slightly larger trial similarly found improvements in anxiety and stress symptoms, and a 2020 systematic review found benefits for mild depression symptoms and anxiety. But the benefits didn’t show up in studies specifically in people with panic disorder or generalised anxiety disorder, both of which typically require management by a physician.

“For anyone who is experiencing suicidal thoughts or severe functional impairment,” such as “anxiety so severe that they’re having trouble leaving their house or engaging with their family or friends or going to work, I wouldn’t necessarily start off with magnesium,” Brown says. “At that point, you definitely want to make sure you’re working with a mental health professional therapist or psychiatrist.”

What about better sleep?

While evidence for magnesium’s benefits for mild anxiety seem encouraging, its benefits for sleep remain unproven. Brown mentioned that insomnia that’s caused primarily by mild anxiety might improve with magnesium, but that doesn’t mean magnesium can help with insomnia more broadly.

“The evidence is weak,” says Muhammad A. Rishi, an associate professor of medicine at Indiana University School of Medicine in Indianapolis. “The studies that mostly show some positive association with improved sleep are observational, which basically tell us there may be a connection, but they’re not cause and effect.” Research suggesting people with magnesium-rich diets sleep better, for example, might mean those people have other helpful habits, such as exercising daily, says Rishi, also vice chair of the Public Safety Committee of the American Academy of Sleep Medicine.

For example, a systematic review in 2021 found only three randomized controlled trials, with 151 total participants, assessing magnesium’s effects on sleep. The results suggested magnesium helped people fall asleep 17 minutes faster, but they didn’t find that people slept any longer, and the trials were low quality.

A 2022 study of nearly 4,000 participants found borderline improvement in sleep quality, but it was an observational trial, and the benefits did not occur in people with depression. The most recent systematic review, published in January this year, also saw benefits in observational trials but only contradictory results in randomised controlled trials. They also had few participants, and the trial duration was too short to yield meaningful answers.

“Most sleep doctors will not prescribe magnesium for somebody having poor sleep quality because we just don’t have the data, so most of the patients taking magnesium to improve sleep are taking it unsupervised,” Rishi says. Poor sleep quality can also encompass a wide range of problems: trouble falling asleep, trouble staying asleep, or sleeping fine but waking up too early and not falling back asleep. “Obviously, each needs a different type of treatment regimen,” Rishi says.

Tips on taking magnesium supplements

Those who want to try magnesium supplements should be aware of the different forms, Brown says. Magnesium citrate is typically used as a laxative to treat constipation or to prepare for procedures related to the bowel, such as colonoscopies. Magnesium oxide is most often recommended for migraines, but studies suggest it’s not absorbed well. Magnesium malate is most often taken for muscle aches and fatigue. Brown recommends magnesium glycinate, similar to magnesium gluconate, because it’s the best studied for anxiety, has less of a laxative effect, and is absorbed better.

Brown recommends people “start low and go slow,” such as initially taking 100 mg and seeing how your body responds before increasing the dose, especially because of that laxative effect. Other side effects could include feeling a bit sleepy or sluggish or a reduction in blood pressure. Those taking medication to lower blood pressure should consult a physician to ensure they don’t lower their blood pressure to dangerous levels.

Magnesium is also sometimes recommended for heart palpitations, but people with an irregular heartbeat or seeing a cardiologist should talk to them before starting supplements. Other medications that may interact with magnesium supplements include certain antibiotics, proton pump inhibitors, diuretics, and medications used to treat osteoporosis.

Although the kidneys will eliminate excess magnesium consumed through food, high doses from supplements can carry risks, so the Institute of Medicine recommends taking no more than 350 mg of supplements per day (separate from quantities consumed through food).

“Whatever supplements you take,” Brown says, “your doctor should always be aware because they can interact with certain medications.”

Source: NATIONAL GEOGRAPHIC