Does Magnesium Help with Sleep?

Magnesium is critical for athletes and active individuals — it’s essential for muscle recovery and better sleep, plus regulating key hormones like cortisol. It not only promotes rest and relaxation but also helps your body use other crucial nutrients, like vitamin D. Let’s take a closer look at what makes magnesium such a vital nutrient and how it can help you get a better night’s sleep. 

In a study published in February 2021, researchers randomly assigned subjects to take either magnesium or a placebo pill for 24 weeks. The researchers then measured the subjects’ levels of cortisol, the stress hormone, over a 24-hour period. They found the magnesium group had significantly lower cortisol levels and an increase in a compound called 11β‐HSD type 2, which keeps the body from over-activating cortisol production (4).

Another study reviewed 18 items of research into the effects of magnesium supplements on stress and anxiety. It found that magnesium has a beneficial effect on anxiety (5).

If you compare today’s most discussed sleep supplements — for example, Thirdzy vs MoonBrew vs Beam Dream — you’ll find they contain magnesium. This is because magnesium is effective at promoting relaxation and an effective sleep supplement when you use it correctly. And if you train hard, the science backs what you might already feel: magnesium can help you sleep deeper and recover faster.

In one study, researchers gave older adults either 500 mg of magnesium or a placebo. In the group that took magnesium, they found a significant increase in total amount of sleep, including less waking up in the night and less time required to fall asleep. The magnesium takers also had higher levels of renin and melatonin, two hormones that help regulate sleep (3).

A different study had adults take magnesium for 20 days and then had them undergo a clinical sleep study. The researchers measured the participants’ brain activity and took blood samples to measure changes in their hormones. This study found that after taking magnesium there was a significant increase in slow-wave sleep (deep sleep) and stronger delta waves, which is a measure of the quality of deep sleep. 

In that same study, there was also an increase in sigma powder, which is an indication of the sleep spindles that happen in the brain when your brain is consolidating memories and communicating well between different brain regions during sleep. This study also found a decrease in cortisol levels.

If you’re on social media, maybe you’ve seen the conversations around “sleepy girl mocktails” — drinks meant to promote the onset of restful sleep. While some brands sell patented versions of this sleep stack beverage, many people make their own concoctions right at home.

Sleepy girl mocktail ingredients usually include a magnesium powder and tart cherry juice, with potentially various other ingredients. Magnesium promotes relaxation, while tart cherry juice contains melatonin and tryptophan, two chemicals that naturally promote sleepiness.

There’s some debate as to whether or not a sleepy girl mocktail recipe is a healthy addition to a person’s sleep routine. For starters, these drinks can be high in sugar, particularly if it’s a patented formula vs. a DIY sleepy girl mocktail recipe. Also, scientists have issued warnings about the negative ways in which melatonin can affect your hormones and metabolism — not ideal if you care about hormonal balance, recovery, or waking up clear-headed.

For sleep, we recommend taking 200 to 400 mg per day of a chelated magnesium that will be easy on your digestive system. A chelated magnesium is a magnesium bound to another type of molecule, such as an amino acid. Certain chelated magnesiums, such as magnesium bisglycinate, are easier for your gut to digest, while others, such as magnesium citrate, can cause loose stools.

Health professionals recommend a magnesium intake of 400 to 420 mg per day for adult men and 310 to 320 mg per day for adult women. That requirement increases for women who are pregnant or breastfeeding. 

Magnesium plays an important role in:

• Making the brain chemical GABA, which makes you feel calm and initiates sleep.
• Stress reduction and stabilizing your moods.
• Regulating your heart beat.
• Bone and muscle formation.
• Maintaining hydration and fluid balance (it's an important electrolyte).
• Calming the nervous system and muscle contractions.
• 300-plus different enzyme reactions.

Your body requires magnesium in order to properly metabolize and use vitamin D, a nutrient that’s vital to the health of your immune system.

Research has shown that having adequate vitamin D levels lowers your chances of developing infections or getting sick with common colds, COVID-19, and other illnesses.

So, as you can see, magnesium is kind of a big deal. And, as an essential nutrient, magnesium is a nutrient your body can’t make itself. Instead, you have to get it in your diet, such as by eating plenty of leafy greens, seeds, beans, and nuts.

For many people, eating a magnesium-rich diet is enough to maintain their magnesium levels and promote healthy sleep. However, studies suggest that 75% of Americans do not meet their dietary requirements for magnesium, resulting in low magnesium. In those instances, a magnesium supplement can be helpful.

An obvious cause of low magnesium is not eating enough of it in your diet. But even with a clean diet, active people burn through more magnesium — intense training, frequent sweating, and physical stress all deplete your stores faster than average, and you burn through even more when you are stressed or sick. Some people argue that even our soil is depleted of magnesium, which would mean our food sources lack magnesium in the first place.

When you are low on magnesium, your body pulls it from your bones to use elsewhere. Over time, this can decrease your bone density and put you at risk for osteoporosis. People almost never show low levels of magnesium on blood tests, because their body will use stored magnesium to keep their blood levels normal. It’s therefore hard to detect deficiencies without invasive procedures. 

A 2018 article published in the British Medical Journal's “Open Heart” publication warned: "The literature suggests that subclinical magnesium deficiency is rampant and one of the leading causes of chronic diseases, including cardiovascular disease and early mortality around the globe, and should be considered a public health crisis.(1)"

Signs of low magnesium include: 

• fatigue

• muscles weakness

• muscles twitches and cramps

• irregular heartbeat

• depression

• anxiety

• restless sleep and waking frequently during the night

Given these negative effects, it is easy to see how bumping up your magnesium intake could help your brain and body to relax, wind down, and sleep better. Particularly if you’re an athlete who trains at a high intensity, sleep is crucial to give your muscles a chance to recover. For example, CrossFit athletes need more sleep than most people think.

There are a lot of different types of magnesium. The ones that your body can best absorb and use are forms of chelated magnesium, which means the magnesium is attached to another molecule, such as an amino acid or organic acid. Here are some of the most common forms:

• Magnesium bisglycinate: Your gut can easily absorb magnesium bisglycinate, aka magnesium glycinate, and it tends to have better tissue uptake (use in your body) than other forms. Unlike magnesium citrate, magnesium glycinate doesn’t cause loose stools.

• Magnesium citrate: This common form of magnesium is safe for consumption and highly absorbable but tends to produce loose stools.

• Magnesium chloride: This salt form is common in bath salts, relying on your skin to absorb it. Soaking in it can help relax sore and tight muscles, but as an oral supplement, it can lead to diarrhea.

• Magnesium gluconate: This form is generally easy on your digestive system and is less likely to cause loose stools compared to magnesium citrate or magnesium oxide.

• Magnesium malate: This highly bioavailable form of magnesium is attached to malic acid vs. an amino acid. People use it to reduce muscle fatigue as well as the pain associated with fibromyalgia.

• Magnesium oxide: This type contains more magnesium than other types but is common as a laxative because it can cause loose stools and diarrhea.

Ideally, your diet should provide all the magnesium your body needs on a daily basis. However, in certain cases, it may be necessary to take a supplement. In that case, it’s imperative you always follow the provider’s guidelines. Taking too much could lead to unwanted side effects, such as an upset stomach, cramping, or diarrhea.

For sleep and night time relaxation, take 250 mg of magnesium 30 to 60 minutes before bed. This gives your body time to absorb the mineral and to begin experiencing its calming effects before you plan on drifting off to sleep.

If you’re on any other supplements or herbs for sleep, try to avoid taking them at the same time as your magnesium, as they could interfere with your body’s ability to absorb the magnesium. It can, however, be a good idea to take your magnesium with a light snack vs. an empty stomach to avoid any digestion problems.

If you’re brand-new to supplementation, consider starting with a smaller dose of magnesium and then gradually working your way up to the 250 mg. Always consult your doctor before starting a new supplement or changing your dose.

Magnesium can help you unlock deeper sleep cycles — where your body does the real recovery work. If you train hard, you need more than rest … you need restorative sleep.

Sleep tight,

Dr. Justine Luchini

Magnesium helps regulate neurotransmitters like GABA, supports melatonin production, and lowers cortisol levels — all of which promote relaxation and deeper, more restful sleep. 

Magnesium glycinate is widely considered the best for sleep because it’s calming, well-absorbed, and also supports anxiety reduction. 

Magnesium might help people with sleep apnea by reducing inflammation and relaxing their muscles. However, taking magnesium alone is not a comprehensive treatment plan for sleep apnea. 

Yes, magnesium supports muscle relaxation, reduces cramping, and helps repair tissues by assisting with energy production and protein synthesis. 

Take magnesium about 1 hour before bed, ideally with food, for the best absorption and to support your body’s natural sleep cycle. 

Many people can meet their needs through a magnesium-rich diet (e.g., leafy greens, seeds, and beans), but stress, sweating, or health conditions may increase their requirements. 

Common signs of magnesium deficiency include fatigue, muscle cramps, poor sleep, anxiety, and irregular heartbeat. Severe deficiency can cause more serious symptoms like seizures. 

Topical magnesium sprays and bath salts may help with muscle relaxation, but there’s little evidence that these have greater sleep benefits compared to oral magnesium supplements. 

Yes, for most healthy adults, taking magnesium every night is safe within recommended limits (310 mg to 420 mg per day), but it’s best to consult a healthcare provider, especially if you have underlying conditions. 

High doses can lead to diarrhea, nausea, or cramping — especially with forms like magnesium oxide or chloride — so it’s important to stay within your healthcare provider’s recommended amounts. 

So-called sleepy girl mocktails may offer mild sleep benefits, thanks to the magnesium and tart cherry juice’s melatonin, but they can be high in sugar and are not a guaranteed fix.

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*** The views expressed in this article are those of one expert. They are the opinions of the expert and do not necessarily represent the complete picture of the topic at hand. This article is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. 

References

1. DiNicolantonio, James J et al. “Subclinical magnesium deficiency: a principal driver of cardiovascular disease and a public health crisis.” Open heart vol. 5,1 e000668. 13 Jan. 2018, doi:10.1136/openhrt-2017-000668

2. Cao, Yingting et al. “Magnesium Intake and Sleep Disorder Symptoms: Findings from the Jiangsu Nutrition Study of Chinese Adults at Five-Year Follow-Up.” Nutrients vol. 10,10 1354. 21 Sep. 2018, doi:10.3390/nu10101354

3. Abbasi, Behnood et al. “The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial.” Journal of research in medical sciences : the official journal of Isfahan University of Medical Sciences vol. 17,12 (2012): 1161-9.

4. Schutten, Joëlle C et al. “Long-term magnesium supplementation improves glucocorticoid metabolism: A post-hoc analysis of an intervention trial.” Clinical endocrinology vol. 94,2 (2021): 150-157. doi:10.1111/cen.14350

5. Boyle, Neil Bernard et al. “The Effects of Magnesium Supplementation on Subjective Anxiety and Stress-A Systematic Review.” Nutrients vol. 9,5 429. 26 Apr. 2017, doi:10.3390/nu9050429