The Research On Magnesium Supplements For Sleep & Which Ones Are Best At Bedtime*

Magnesium is an essential mineral to the human body that has an important role in energy production, bone development, muscle contraction, and much more.*

"The ability of our nerves to transmit signals throughout our entire central nervous system (brain, spinal cord, etc.) is dependent on magnesium. The metabolism of carbohydrates and fats for ATP energy requires magnesium. The regulation of blood pressure and heart rate directly involves magnesium. This mineral is even required for the production of DNA, RNA, and proteins. Talk about ubiquitously important,"* explains mbg's vice president of scientific affairs Ashley Jordan Ferira, Ph.D., RDN.

Our bodies cannot produce magnesium, so we must consume this essential macromineral daily through diet. This can be easier said than done, as some industrial agricultural practices strip the essential mineral out of food.

It's estimated that 43% of U.S. adults1 currently fail to meet their daily needs through diet alone. Ferira adds, "To put this magnesium deficit in further perspective, we're talking about over 100 million adults failing to achieve their nutritional requirements daily."

The magnesium in our bodies also tends to naturally dip as we age, due to reduced intestinal absorption, reduced bone storage, and excess urinary loss. This makes maintaining healthy magnesium levels a lifelong endeavor for many.

Naturopathic sleep doctor Catherine Darley, N.D., adds that magnesium also assists with the production of certain neurotransmitters that promote relaxation and quiet nerve activity—most notably, gamma-aminobutyric acid (GABA).* "As an agonist of GABA pathways, magnesium is thought to directly and positively impact relaxation and sleep architecture,"* adds Ferira.

While the mineral clearly plays a role in the sleep process, integrative neurologist Ilene Ruhoy, M.D., Ph.D., notes that the clinical research on magnesium supplementation for sleep is mixed, and a larger body of randomized controlled trials is needed. She also cautions that anyone with a diagnosable sleep problem will want to consult with their doctor for a personalized treatment plan. "Magnesium is not necessarily the panacea for all sleep issues," Ruhoy adds.

In a small 2012 study in the Journal of Research in Medical Sciences3, researchers monitored a group of 46 elderly people (age 60 to 75 years) for eight weeks. Compared to those who were given a placebo, those who took magnesium daily showed statistically significant improvements in sleep onset latency, sleep duration, and sleep efficiency (the percentage of time spent asleep while in bed).*

Additionally, Ferira notes that magnesium has been shown via a 2002 EEG study to increase slow-wave sleep—the deep sleep stage that is essential for memory consolidation and muscle repair.* The same research5 found that magnesium may help regulate our HPA axis, quelling the energizing fight-or-flight stress response.*

Beyond its potential sleep benefits, there are plenty of other reasons to supplement with magnesium daily—especially if you are not getting enough of the mineral from food alone.* Ferira shares that magnesium "promotes electrolyte balance, because it is an electrolyte, as well as muscle relaxation6."*

Ruhoy and Darley note that the mineral plays a critical role in vitamin D transport and activation in the body, plus kidney health, blood pressure balance, and more7.* "Hence, the reason I often recommend magnesium supplementation for clients," Ruhoy adds.

All magnesium supplements pair the mineral with another compound (e.g., oxygen for the oxide form, glycine for the bisglycinate form, citric acid for the citrate form, etc.) to assist with its delivery. When it comes to the best type of magnesium supplement for sleep, Ruhoy says it's typically magnesium glycinate.*

"Magnesium glycinate is easily absorbed, does not have many GI side effects, and contains glycine,"* she explains. The amino acid glycine has sleep benefits of its own and has been shown to make it easier to fall asleep and stay asleep8 and reduce daytime sleepiness9.*

No matter what form of magnesium you're taking, you'll want to stay below the NIH's tolerable upper intake level for supplemental magnesium sources, specifically, 350 milligrams10 (unless otherwise instructed by a doctor). Darley says a dose of 200 milligrams before bed will be plenty for most people.

While you can really take a magnesium supplement at any time of the day, those who are using it for sleep will want to do so in the hours leading up to bedtime.* The exact timing depends on the person, the type of magnesium, and the exact supplement.

"If the magnesium supplement contains other sleep-supporting ingredients, then the entire arc of that formula should be considered for the timing of consumption,"* notes Ferira.

For example, we recommend taking mindbodygreen's sleep support+ formula—which pairs magnesium bisglycinate (i.e., the magnesium mineral plus two amino acid glycine molecules) with jujube extract and PharmaGABA®—30 minutes to two hours before bed. "PharmaGABA® would drive the time-to-take discussion and decision making since its clinical efficacy is shown at 30 minutes to a couple of hours before bedtime," Ferira explains.*

You'll also want to consider your own sleep needs: If falling asleep is a challenge for you, taking a supplement on the earlier side will help it kick in by the time you get into bed. If staying asleep is the issue, you could likely take it closer to your snooze.

Finally, the timing will depend on the type of magnesium you're taking. Since less absorbable forms like magnesium oxide can stimulate the bowels, you definitely won't want to take those too close to bedtime to save yourself a midnight bathroom run.

Magnesium glycinate tends to be the best type of magnesium supplement to take for bed because it's gentle on the stomach and easy for the body to absorb12.*

When searching for the right magnesium glycinate supplement for nightly use, you'll want to look for something that's easy to incorporate into your routine—be it a capsule or powder to add to bedtime brews. Some magnesium supplements need to be taken with food, which is also important to note.

Be sure to look for a supplement that has a short, scannable ingredient list that is free of binders, preservatives, and artificial colors or flavors. If the supplement contains any other active ingredients beyond magnesium, those should be backed by clinical research. mbg's list of the year's best sleep supplements might be helpful as you start your search.

There is no one magic bullet that ensures great sleep night after night (alas!), and consistent high-quality rest stems from a solid sleep routine. Sleep supplements can be beneficial adds to your nighttime arsenal, and magnesium (specifically, magnesium bisglycinate) can be a helpful one for a number of reasons that extend far beyond the bedroom.*