Can a Magnesium Supplement Really Help You Sleep? Here’s What the Science Says

Popping the occasional magnesium supplement for better sleep may have once been a habit reserved for niche wellness circles. But we’re now living in the era of Big Sleep, where the promise of a hand-to-mouth insomnia fix looms big, and people are sucking down the “sleepy girl mocktail”—a concoction of tart cherry juice, magnesium powder, and sparkling water that went TikTok-viral in 2023—with every hope that it’ll live up to its name. And you can’t blame ’em: It only makes sense that a supplement with so much street cred for good shuteye should have at least some science behind it…right?

Broadly speaking, magnesium is a mineral that helps facilitate a bunch of chemical reactions in your body, allowing for everyday muscle movements and nerve function, regulating your blood pressure and sugar level, and contributing to the development of protein, bone, and DNA. It’s also something your body can’t make itself, so you have to get your supply from outside sources—ideally, from whole foods like leafy greens, nuts, legumes, and fish. The daily recommended amounts are 310 to 320 milligrams for women and 400 to 420 milligrams for men, but it can be challenging to hit that number with diet alone: An estimated 48% of Americans fall short of consuming that much magnesium from food. It doesn’t help that commercial food-processing practices have likely stripped some magnesium out of produce that would naturally contain more of it, Sasikanth Gorantla, MD, a neurologist and sleep medicine specialist at the University of California Davis, tells SELF.

There’s a bit of research to suggest that being chronically deficient in magnesium can, in fact, raise your risk of poor sleep or a sleep disorder (like insomnia or excessive daytime sleepiness), perhaps by interfering with your circadian rhythm (a.k.a. your 24-hour body clock). Because the mineral plays a role in energy production, being super low on the stuff could leave you fatigued throughout the day—and though it sounds counterintuitive, constant daytime tiredness could lead to insomnia by weakening the link in your brain between nighttime and sleepiness, Brian Chen, MD, a sleep medicine physician at the Cleveland Clinic, tells SELF.

But even if you’re not regularly hitting your recommended amount of magnesium with food, it’s unlikely for your body to become so deficient that you experience symptoms, Dennis Auckley, MD, a professor of medicine at Case Western Reserve University and director of the Center for Sleep Medicine at MetroHealth Medical Center, in Cleveland, tells SELF. That’s because most people’s kidneys will account for a lower intake by holding onto more magnesium when it’s in short supply. (The main exceptions are folks with GI conditions that affect their absorption of magnesium, and people with type 2 diabetes or alcohol dependence, both of which can prompt the kidneys to excrete too much of it.)

So if you’re not experiencing symptoms of magnesium deficiency, can ramping up your intake have any effect on your ability to doze off easily or snooze soundly? Here, experts break down the potential connection between magnesium and sleep, and what you need to know if you’re considering adding this supplement to your pre-bed ritual.

Magnesium has a couple effects on the body that may indirectly impact your sleep.

All the hype around guzzling magnesium for sleep likely comes from a few things we know about how the mineral functions in the brain. For starters, magnesium essentially tells your NMDA receptors—which are involved in anxiety and excitability—to chill out, which may help calm you down. And it also has the opposite effect on GABA receptors, which promote sleepiness, by binding to them and boosting their activity, Dr. Auckley says. This is similar to how sleeping pills like benzodiazepines (e.g. Valium and Xanax) and “Z” drugs (e.g. Ambien, Sonata, and Lunesta) work, he explains. Together, these properties of magnesium may produce an anti-anxiety effect and promote relaxation, making sleep more likely to happen.

At the same time, when you have enough magnesium blocking up those NMDA receptors, calcium won’t be able to flow into and build up inside your muscle cells, Dr. Gorantla says, where it could otherwise trigger cramps and spasms. So having sufficient magnesium in your body may create a muscle-relaxing effect, which could theoretically help you fall asleep more easily. That link is mostly relevant to folks who deal with nighttime leg cramps or restless leg syndrome (RLS), which is a condition involving an irresistible urge to move your legs in bed that can leave you struggling to doze off. Building on a 2022 study finding that magnesium supplementation improved sleep quality in people with RLS (based on questionnaires they completed), Dr. Gorantla conducted research to additionally assess if the supplement could reduce self-reported discomfort and periodic leg movements (as measured with a device). He found that it did—which is promising—but notes that these results should be replicated in a larger, placebo-controlled study.

There isn’t solid research to show that taking a magnesium supplement can directly improve sleep.

All of the above shows how ingesting ample magnesium may theoretically make you sleepier, but we still don’t know “the magnitude of these impacts and how clinically relevant they are,” Dr. Auckley says. Which is to say, it’s not clear whether a magnesium supplement—or even a bunch of magnesium-rich foods, for that matter—can really act like a chill pill in your body (especially if you weren’t measurably low on the mineral to begin with), and if it can, whether it would be enough to knock you out. (If you feel sleepier after taking magnesium, it also may be psychological: Taking any pill that you think will help you doze can put you at ease—which could then help you drift off.)

The magnesium research on sleep, specifically, consists mostly of small studies investigating specific demographics, many of them observational in nature, Dr. Auckley says, meaning scientists just looked for sleep benefits in folks who were taking magnesium by choice at home. In a 2023 review, researchers found that, overall, these less-definitive studies do show a link between magnesium intake and better sleep quality. But crucially, they didn’t find any significant connection when they analyzed the few randomized controlled trials done in this arena (in which scientists assigned folks randomly to the placebo or experiment group and controlled for other variables in a lab setting). Ultimately, they concluded that we just don’t have enough high-quality data yet to clarify the association between magnesium and sleep.

Another factor that muddies the water? Magnesium supplements are not all created equal. There are a bunch of different types out there (magnesium citrate, glycinate, and oxide, to name a few), and they vary in their potential effects and bioavailability (a.k.a. how easy it is for your gut to absorb). Not to mention the broad issue that comes into play with any supplement: There’s no guarantee that you’re getting exactly what’s on the label—and nothing that isn’t—because the industry doesn’t receive the same oversight by the Food & Drug Administration as OTC and prescription meds do, Dr. Auckley says.

Bottom line: You’ll see more benefits by addressing the root cause of your sleep issues than from popping a supplement.

A magnesium supplement is generally low-risk to take, given the mineral is something we can (and should) consume plenty of via food. That said, it’s always a good idea to clear the supplement with your doctor first, particularly if you have (or once had) a heart condition, because electrolytes like magnesium can influence cardiac function, Sam Kashani, MD, a board-certified sleep medicine specialist at UCLA Health, tells SELF. You’re also at increased risk for complications if you have kidney problems, which may make it tougher for your kidneys to regulate your levels of the mineral. Separately, a magnesium supplement could mess with the function of some meds, for instance, reducing the efficacy of common antibiotics or increasing your absorption of certain diabetes drugs.

Otherwise, taking magnesium within the recommended dosage (no more than 350 mg daily in supplement form) is unlikely to cause any major side effects. The main thing you might experience is some GI upset or diarrhea, Dr. Gorantla says. Magnesium citrate, in particular, “absorbs water and can function as a laxative,” he says, which may help with constipation (but probably isn’t what you want when you’re trying to get a full night’s rest).

But the truth is, relying on any substance to sleep, no matter how low-risk it might be, is a Band-Aid at best, rather than a long-term solution for the underlying cause of your sleep difficulties, Dr. Auckley says. Addressing the latter starts with brushing up on your overall sleep hygiene—which refers to both your physical bedroom environment (Is it dark, cool, and quiet?) and your pre-bed routine (Is it helping you mentally and physically wind down?).

If you’re struggling to get a consistent seven to eight hours of shut-eye or your lack thereof is impacting your day-to-day functioning, it’s important to start a conversation with your doctor, and ideally see a sleep specialist. They can offer a variety of long-lasting treatments, including cognitive behavioral therapy for insomnia (CBT-I), which focuses on identifying habits and thought patterns you’ve picked up that are counterproductive to sleep, and swapping them for behaviors that directly facilitate it, Dr. Auckley says. Sure, it takes longer than cracking open a pill bottle, but it’s also making use of the most reliable sleep aid out there: Yourself.

Related:

• If Melatonin Isn’t Addictive, Why Can’t I Stop Taking It?
• How to Get Better Sleep If You Have ADHD, According to Therapists Who Also Have ADHD
• This Simple Morning Habit Can Help You Sleep Way Better at Night

Get more of SELF’s great service journalism delivered right to your inbox.