How this essential mineral can help with sleep and other important bodily functions

If you find yourself tossing and turning at night, the solution might not be a heavy sedative but a vital micronutrient already present in your kitchen.

Magnesium, an often overlooked ally for better rest, is an essential mineral that plays a quiet but crucial role in helping the body wind down and so much more.

It doesn't force sleep, but prepares the brain and nervous system for it.

According to Dr. Wendell A. Tulay, a board-certified adult disease specialist and a diplomate in internal medicine of the Philippine Colleges of Physicians, magnesium supports sleep by regulating key biochemical pathways involved in relaxation and stress control.

“Magnesium supports better sleep by calming brain activity, strengthening the brain’s natural inhibitory signals through NMDA receptors, regulating the body’s sleep hormone (melatonin), and reducing stress-related cortisol levels, which in turns helps the nervous system shift into a stable, sleep ready state rather than acting as a sedative like other sleeping pills/ supplements,” he said.

Unlike sleeping pills, magnesium does not act as a sedative. Instead, it creates the internal conditions needed for sleep to occur naturally.

According to a 2012 study, magnesium regulates the central nervous system by increasing sleep-promoting markers like melatonin and renin, while significantly decreasing concentrations of the stress hormone cortisol.

These biological adjustments result in significant improvements in sleep efficiency and duration, providing a potential alternative to conventional hypnotic medications that are often associated with more hazards than benefits in elderly populations.

But Magnesium supplements come in different forms, and their benefits depend largely on their formulation.

Tulay notes magnesium glycinate and magnesium L-threonate are most commonly used for sleep and cognitive support because they are well absorbed and active within the central nervous system.

“Magnesium glycinate is the most commonly recommended form for sleep because it is highly bioavailable, gentle on the stomach, and combined with glycine, an amino acid that promotes relaxation and sleep initiation,” he explained.

Magnesium L-threonate is another promising option, as it is “capable of crossing the blood–brain barrier and increasing brain magnesium levels, which may support sleep quality and nighttime brain calmness.”

Both forms have been shown to enhance GABA activity, which, according to a 2024 study, is the primary inhibitory neurotransmitter system in the central nervous system that helps counterbalance excitatory neurotransmitters and reduce alertness during sleep.

Other forms of magnesium serve different purposes, too.

Magnesium citrate and magnesium oxide are often used for constipation and digestive concerns due to their osmotic effects, while magnesium taurate and magnesium malate are linked to cardiovascular support, muscle function, and energy metabolism.

When should magnesium be taken?

Timing matters when taking magnesium.

“The best time to take magnesium depends largely on the intended benefit, as different physiologic effects differ at the time of the day,” Tulay said.

If you're interested to take magnesium for sleep and stress-related benefits, consider taking it one to two hours before bedtime, as its effects on GABA signaling and cortisol suppression support the body’s natural transition to sleep.

According to a 2011 study, administering magnesium in the evening is particularly effective for rest as it has been shown to decrease cortisol levels during the first part of the night while significantly increasing the duration of restorative slow-wave sleep.

For digestive purposes, consider taking it earlier in the day or early evening to avoid nighttime discomfort.

Meanwhile, those taking magnesium for muscle function, heart health, or energy metabolism may tolerate it better when taken in the morning with breakfast, as some formulations can be mildly activating.

“Overall, studies note that while magnesium can be taken at any time of the day, knowing and aligning the desired physiologic effect may improve both effectiveness and its tolerability,” Tulay said.

How much magnesium do adults need?

Tulay said there is no Philippine FDA–specific recommended dietary allowance (RDA), but the country follows international dietary guidelines:

• Men (19–30 years): 400 mg/day
• Men (31+ years): 420 mg/day
• Women (19–30 years): 310 mg/day
• Women (31+ years): 320 mg/day

“These amounts refer to total magnesium intake from food and supplements combined. For better sleep support, studies showed to use the supplemental doses of 250–500mg a day, typically taken before bedtime,” he explained.

Magnesium supplements are generally available over the counter and do not require a prescription but consulting a healthcare professional before starting supplementation is still important, especially for individuals with underlying medical conditions, those taking maintenance medications, or people planning to use magnesium regularly for sleep or stress support.

Proper guidance helps ensure the correct dosage, formulation, and safe use.

“Medical guidance helps ensure the correct formulation, dose, and timing, and reduces the risk of side effects or drug interactions,” Tulay said.

When to reassess supplementation

There is no fixed maximum duration for magnesium supplementation in otherwise healthy adults.

“But having said that, we still recommend periodic reassessment rather than indefinite use, particularly if magnesium is being taken daily. For sleep support, magnesium may be used continuously for 4–12 weeks, after which individuals can evaluate whether benefits persist or whether supplementation can be reduced or paused while maintaining adequate dietary intake,” Tulay said.

A clinical trial in 2012 found that 500 mg of daily magnesium supplementation for eight weeks significantly improved both subjective and objective measures of insomnia in elderly participants, specifically increasing sleep efficiency and melatonin levels while decreasing serum cortisol.

However, researchers noted that this 8-week duration resulted in only a marginally significant increase in serum magnesium levels, suggesting that such a timeframe might be inadequate to observe a full physiological shift in magnesium homeostasis.

This clinical evidence highlights that reassessment should occur after at least eight weeks of consistent use to determine if the intervention has effectively improved sleep quality and modulated relevant biochemical markers

Magnesium-rich foods to include in your diet

Magnesium can also be obtained naturally through food.

Per Dr. Tulay, green leafy vegetables such as spinach and kale, nuts and seeds like almonds, cashews, pumpkin seeds, and sunflower seeds, legumes including lentils and black beans, whole grains such as oats and brown rice, and even dark chocolate are rich sources of the mineral.

“Incorporating these foods regularly can help maintain adequate magnesium levels and may complement supplementation for sleep support,” he said. “Be patient, magnesium’s effects on sleep may take several days to weeks to become noticeable.”

Who should be cautious?

Magnesium is generally safe for most adults, but excessive intake can cause diarrhea, nausea, and abdominal cramping.

“People with kidney disease or severe renal impairment should avoid magnesium supplementation unless prescribed by a medical doctor, as their kidneys cannot efficiently regulate excess magnesium,” Dr. Tulay said.

Those taking certain medications, including some antibiotics and diuretics, should also consult a doctor to prevent possible interactions.

According to the Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes’ “Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride,” magnesium naturally occurring in food has not been shown to cause adverse effects, even when large amounts are consumed. However, excessive intake from nonfood sources like pharmacological salts can cause osmotic diarrhea, which may be accompanied by nausea and abdominal cramping. 

To protect against these symptoms, the recommended dietary allowance must be followed.

Furthermore, magnesium transport and levels in the body can be influenced by various pharmacological factors.

Specifically, diuretics used for conditions like hypertension or heart failure are known to increase renal magnesium excretion, which can eventually lead to magnesium depletion. Such depletion is clinically significant as it can result in cardiac complications like arrhythmias or an increased sensitivity to cardiac glycosides.

The bigger picture: diet, habits, and sleep

Magnesium works best when paired with healthy sleep habits. 

“Helpful habits include maintaining a consistent sleep schedule, practicing relaxation or mindfulness before bedtime, engaging in regular exercise (but not immediately before bed), reducing caffeine and alcohol intake in the evening, and limiting screen time one to two hours before sleeping,” Dr. Tulay said.

On the other hand, late-night heavy meals, irregular sleep patterns, excessive device use, and unmanaged stress can interfere with rest.

“Magnesium supports sleep but is not a sedative; it works best alongside healthy sleep habits,” he noted. “Always consider diet first, using supplements to fill gaps rather than replace food.”

Even though magnesium is generally safe, consulting a doctor before starting supplementation ensures the right dose, formulation, and timing while minimizing risks. — LA, GMA Integrated News