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A popular scene is playing out on TikTok right now. People with sizeable silk sleep masks wrapped around their heads can be seen popping magnesium supplements before bed—and with good reason. But the question remains: How much magnesium per day is needed to start to feel the benefits?
This OG mineral plays a vital role in over 300 physical functions to keep your body humming along nicely. It improves heart and brain health, supports the immune system, and contributes to bone formation, to name but a few.
Magnesium gets the most air time, though, as an insomnia fix. I should know: I take magnesium supplements every night to tackle my sleep anxiety. But the other day I spotted magnesium in the ingredients list of a multivitamin that I was advised to take morning and night. I was a bit alarmed. Surely magnesium would make me sleepy during the day?
Actually, no. The best time to take magnesium is more nuanced than I thought and magnesium can also help with energy production. Confused? I was too. It all hinges on the type of magnesium you’re taking and whether you’re supplementing for energy and improved brain function or relaxation and recovery.

Should you take a magnesium supplement in the morning or at night?
Technically, you can take magnesium at any time of day, depending on the benefits you’re hoping to get from it. The main thing is to be consistent and to consider the type of magnesium in your supplement as each form has a different function.
Some tablets have just one type of magnesium—typically magnesium glycinate, which is best taken before bed to get a good night’s sleep.
Others, like Artah’s Essential Magnesium and Beauty Pie’s Daily Magnesium, combine magnesium glycinate and magnesium malate, so you can tailor it to your needs. Either take one capsule morning and night, or take both capsules in the evening if you want to encourage a restful night’s sleep.
Magnesium glycinate: This form of magnesium is bound to the amino acid glycine and is best taken before bed. “Glycine has a calming effect on the nervous system and helps to regulate core body temperature, which may aid sleep and stimulate muscle growth,” says Rhian Stephenson, a nutritionist and the founder of Artah.
Magnesium malate: Here, magnesium is bound to malic acid, “which is important for energy production,” says Stephenson. “Magnesium malate provides specific support for energy, athletic performance, and cognitive energy,” she adds, so it can be taken in the morning to get your day going or in the afternoon to beat the midday slump.
Magnesium citrate: This mix of magnesium and citric acid helps to support muscle function but can also be useful if you suffer from occasional constipation as it kick-starts bowel movement. It can be taken in the morning or evening.
Benefits of taking magnesium in the morning
It may be best to take magnesium supplements in the morning if you are using them for energy, anxiety, brain health, and improved mood.
Magnesium plays an important role in relaying signals between your brain and body. Specifically, it works on amino acids called NMDA and GABA, which act as neurotransmitters in your central nervous system.
If it sounds complicated, that’s because it is. All you need to know is that NMDA and GABA “play an important role in learning and memory,” says Harry Jarrett, head of science and research at Heights. He adds that GABA also helps to regulate stress and calm anxiety in the body, which, in turn, supports concentration and mental clarity.
“Some symptoms of magnesium deficiency can present as restlessness, lack of attention, and fatigue,” Jarrett notes. By improving the quality of your sleep, magnesium will also help you feel more alert the following day.
Magnesium is often referred to as the “calming mineral” because of its role in supporting NMDA and GABA and “the nervous system in general,” says Stephenson, who adds, “it also mediates our stress response. Because of this, it’s been shown to boost mood. Our body uses magnesium stores to help buffer the effects of acute stress. But when stress is chronic, it leads to progressive magnesium loss.”
Low levels of magnesium then exacerbate stress—and you get caught in a vicious cycle. So if you’re going through a stressful time, it’s worth taking magnesium in the morning for support throughout the day.
Magnesium plays a crucial part in the body’s production of energy. Stephenson says, “It’s important in the production of cellular energy,” which ensures that our muscles have enough fuel to function when we work out. “Stress can also be exhausting, which is another reason why magnesium support can help improve energy.”
“Magnesium has a calming effect on the nervous system, but it also plays an essential role in keeping our muscles relaxed,” says Stephenson.
“Magnesium and calcium work together to create muscle contractions; calcium causes muscles to shorten and contract, and magnesium triggers them to relax and lengthen. When we have insufficient magnesium, our muscles can struggle to relax, which in turn, can lead to cramping, spasms, and stiffness.”
Benefits of taking magnesium at night
It’s best to take magnesium supplements at night if you are using them for better sleep, to relieve anxiety, and muscle recovery.
“One way magnesium can improve sleep is by regulating the body’s level of the hormone melatonin,” Jarrett explains. “Melatonin plays a well-documented role in regulating our sleep-wake cycles and can be used for the treatment of insomnia.”
In fact, he says, a recent study found that those taking magnesium supplements (compared to a dummy tablet) had an increase of melatonin in their blood stream and stayed asleep for longer.
According to Jarrett, another way magnesium may boost your bedtime routine is by maintaining healthy levels of the neurotransmitter GABA, which encourages relaxation and a deep sleep. Many sleeping tablets also target GABA for similar reasons, FYI.
“When we exercise, acute inflammation naturally occurs as a part of the recovery process,” says Stephenson. “In addition to its role in relaxing stiff muscles, magnesium has been shown to reduce C-reactive protein, a marker of inflammation, and increase nitric oxide, which encourages blood flow and lactic acid excretion, making it an essential mineral for muscle recovery.”
Benefits of taking magnesium at any time of day
Whether you choose to top up your magnesium in the morning or at night—or take it in a twice-daily multivitamin—you can expect:
A stronger immune system. Magnesium is involved in the adaptive immune system, which protects you from illnesses you’ve had before, says Stephenson. It also supports your first line of defense against new germs and viruses.
Improved bone health. “Magnesium is involved both directly and indirectly with bone health,” says Stephenson. She points out that magnesium helps the body to use bone-strengthening vitamin D and calcium effectively.
It also influences a hormone that regulates skeletal muscle. Around 50% to 60% of the magnesium in your body is found in your bones. When you’re deficient in magnesium, “your body uses the magnesium stored in your bones,” which can interfere with bone formation and contribute to brittle bones and a higher risk of fractures.
A mood boost. One study “reported significant improvements in depression scores following magnesium supplementation,” says Jarrett, who also spotlights its positive effects on melatonin for improved sleep and the stress hormone cortisol.
Improved heart health. Heights recently collaborated with researchers at Kings College London to look at the impact of magnesium on human health. “We found a number of studies reporting that magnesium supplementation lowered systolic and diastolic blood pressure when compared to a placebo, improving heart health,” Jarrett says.
Another study also found that participants with high magnesium intake had a reduced risk of coronary heart disease. This could be because “magnesium is responsible for the movement of important electrolytes such as calcium, potassium, and sodium into the heart muscles, which helps the heart to maintain a healthy rhythm,” he notes.
Fewer migraines. “The same review found a number of studies reported that taking magnesium supplements significantly reduced the frequency and intensity of migraines by up to 42%,” says Jarrett.
It’s truly shocking.
How to get more magnesium
Magnesium is an essential mineral, which means the body can’t produce it. That said, it has built-in mechanisms for holding on to magnesium, so an actual deficiency is pretty rare.
It’s still “important to ensure that you have optimal levels of magnesium intake in your diet and, if required, consider supplementation,” says Jarrett, as low magnesium has been associated with “heightened levels of stress, anxiety, and cognitive issues.”
Good sources of magnesium include vegetables such as spinach, brussels sprouts, broccoli, edamame, and black beans. Avocado and bananas are high in this mineral, too, or try snacking on pumpkin seeds, almonds, and cashew nuts. A portion of salmon served with quinoa or brown rice will also boost your magnesium intake.
While it’s possible to get enough magnesium from our diets, it’s not often happening, says Stephenson. “The National Diet + Nutrition Survey revealed that, in the UK, most of us aren’t getting enough magnesium from food alone.” The best magnesium supplements can offer additional support should you need it.
How much magnesium should you take in a day?
According to the NIH, the recommended amount of magnesium that women over 30 need is 320 milligrams a day; women who are under 30 but older than 19 need 310 milligrams. It’s important to stick to these recommended guidelines as “very high doses in magnesium supplements [over 350 milligrams] can cause unwanted side effects such as diarrhea and, in more serious cases, irregular heartbeat and muscle weakness,” warns Jarrett.
The bottom line? “Magnesium is one of the most powerful minerals out there; not only for cognitive and emotional well-being, but for energy, metabolism, and rest,” Stephenson says. “It really does it all.”
Disclaimer: Vitamin supplements are not a replacement for a healthy balanced diet. Before supplementing, it’s best to consult with your doctor and/or a registered dietitian.
This story originally appeared on Glamour UK.