Does Magnesium Help You Sleep Better?

If you’ve been struggling with sleep issues, you may have heard that magnesium supplements can help. But the truth is a bit more complicated.

Integrative medicine specialist Naoki Umeda, MD, shares what to know about taking magnesium for sleep.

How magnesium may help you sleep

“Overall, the evidence for magnesium as a sleep aid is thin. But some people find it helps them,” Dr. Umeda says. “Magnesium may help regulate neurotransmitters that are directly involved in sleep and relaxation, like GABA.”

Neurotransmitters are chemical messengers between nerve cells in your brain and body. Magnesium plays a supporting role in how they function.

Some preliminary studies suggest that magnesium supplements might:

• Slightly reduce the time it takes to fall asleep
• Support overall sleep quality
• Ease mild, stress-related sleep disturbances

“Most of the studies on sleep and magnesium are small, and the overall evidence is lacking,” he adds. “More research is needed before we can routinely recommend it as an effective treatment for sleep disturbances.”

If you struggle with sleep and are curious about your magnesium levels, Dr. Umeda also points out that blood tests don’t necessarily give you the full picture. Less than 1% of your body’s magnesium is found in your bloodstream. More than 99% is stored in your cells and bones. That means a standard blood test doesn’t provide a full understanding of your magnesium levels. Even if your blood test is normal, it doesn’t necessarily mean you have optimal magnesium levels in your cells or that it tells us how well you’ll sleep.

Types of magnesium to consider for sleep

Two main types of magnesium are considered better options to aid sleep and support your nervous system:

• Magnesium glycinate
• Magnesium L-threonate

Magnesium glycinate

Magnesium glycinate is bound to the amino acid glycine. Preliminary research suggests glycine itself may promote relaxation, improve sleep quality and reduce daytime fatigue. The supplement also tends to be easy to absorb and gentle on your stomach.

Most magnesium glycinate supplements provide 100 to 200 milligrams (mg) of elemental magnesium.

“If you’re going to try magnesium for sleep, starting with 100 to 200 mg nightly is a safe and reasonable approach,” Dr. Umeda says. “For adults, the recommended upper limit for magnesium from supplements is 350 mg per day. Avoid higher doses unless your healthcare provider recommends them.”

Magnesium L-threonate

Magnesium L-threonate is designed to cross the blood-brain barrier more efficiently. It’s mainly been studied for its potential effects on brain function and the connections between brain cells. But limited early research suggests it may also help support sleep.

But here’s where it gets tricky: The amount listed on the front of the label may not tell you how much elemental magnesium you’re actually getting. For example, 2,000 mg of magnesium L-threonate may provide only about 140 to 150 mg of elemental magnesium.

Additionally, magnesium L-threonate supplements often contain other ingredients, too, like vitamins C or D.

“It’s important to know what you’re taking, especially if you already take a multivitamin or other supplements,” Dr. Umeda stresses.

Types of magnesium to avoid for sleep

Not all forms of magnesium are worth considering as sleep aids. Dr. Umeda shares two types that may be helpful in other ways, but aren’t the best options for getting the shut-eye you need.

Magnesium citrate

Magnesium citrate is well-absorbed, but it also has a laxative effect. Taking it before bed can cause an upset stomach or loose stools, which could interfere with your sleep.

Magnesium oxide

Magnesium oxide isn’t absorbed as well as other forms of magnesium. It’s mainly used as a laxative for constipation or an antacid for heartburn. Because it can cause diarrhea, it’s not the best choice for sleep.

How to take it safely

Nonprescription magnesium supplements can often be used safely at the right doses, but there’s risk involved. That’s why you need to do your homework.

The U.S. Food and Drug Administration doesn’t regulate supplements like magnesium. Dr. Umeda recommends checking the label to see if a product has been third-party tested. If it’s verified by the United States Pharmacopeia (USP), for example, that means it meets basic quality standards, but it doesn’t guarantee the product works.

Forms it comes in and when to take it

Most magnesium supplements intended for sleep come in pill form — think tablets or capsules. Other formulations include powders, gummies and drink mixes, but these can contain a lot of other ingredients as well. You can also buy magnesium sprays, but they don’t absorb well enough to help you sleep.

Whatever product you choose, Dr. Umeda urges you to read the product information carefully to understand key features like ingredients, dosing and safety considerations.

“Take your magnesium supplement about 30 minutes before bedtime. That should give it enough time to have an effect,” he advises.

Risks, interactions and side effects

Magnesium supplements are generally safe when taken at recommended doses. But they can interact with some medications, including certain antibiotics, osteoporosis medications and diuretics. Talk to your healthcare provider before taking magnesium if you use prescription medications.

You should also talk to your provider before taking magnesium if you have chronic kidney disease or other kidney problems. Your kidneys help remove excess magnesium from your body. If they aren’t working properly, magnesium can build up to dangerous levels.

Taking more than 350 mg per day from supplements can cause side effects like diarrhea, nausea and stomach cramps. Very high amounts can lead to magnesium toxicity, which can cause muscle weakness, low blood pressure, a slow heart rate and trouble breathing.

Natural ways to get magnesium

Eating a varied diet, including nuts, seeds, leafy green vegetables, legumes and whole grains, can naturally help support magnesium levels in your body.

“It’s widely available in both plant and animal foods,” Dr. Umeda says.

If you want to improve your magnesium levels through food, good sources include:

• Leafy green vegetables, like spinach and Swiss chard
• Nuts and seeds, like pumpkin seeds, almonds and cashews
• Legumes, like black beans, edamame and lentils
• Whole grains, like quinoa, oats and brown rice
• Dark chocolate
• Certain fish, like salmon

While a true magnesium deficiency isn’t very common in healthy adults, your risk may be higher if you:

• Are over age 65
• Have Type 2 diabetes
• Have a gastrointestinal condition, like Crohn’s disease or celiac disease
• Have chronic alcohol dependence

Final thoughts

Bottom line? Magnesium may help some people sleep better, but there’s still not enough research to know how well it works. And it shouldn’t be your first step for managing ongoing sleep problems.

“Start with proven strategies for better sleep,” Dr. Umeda recommends. “Stick to a consistent sleep schedule, limit caffeine and alcohol, keep your bedroom cool and dark, and avoid screens before bed. Cognitive behavioral therapy for insomnia (CBT-I) can also help.

“And if you’re thinking about trying a supplement like magnesium, talk to your healthcare provider first to make sure it’s safe for you.”