How Much Does Magnesium Improve Sleep?

Focus on Magnesium Threonate (the new kid on the block)

Table of Contents
1. Unrefreshing Sleep is a Huge Problem (why I’m writing this blog)
2. Eight Sleep Tips (things that can help if correctly applied)
3. Why Does Magnesium Help With Sleep? (what happens in the brain)
4. How Do We Study Sleep? (how studies are designed)
5. How Much Does Magnesium Improve Sleep? (research summary)
6. Why Might Magnesium Threonate Be Better?
7. My Personal Experience With Magnesium Threonate
8. Conclusions

1. Huge Problem

Most people with complex chronic diseases complain of waking unrefreshed even if they have slept for the recommended 7 – 9 hours/night. It is so common that unrefreshing sleep is one of
the diagnostic criteria for ME, FM and long COVID. “Unrefreshed” is hard to define but generally refers to feeling more like how you felt before bed than how you hoped you would feel after a night’s sleep—tired, fatigued, foggy-headed, having trouble concentrating and not having enough energy or sometimes the motivation to do the things you want to do are common complaints. Low mood and discouragement often accompany unrefreshing sleep as you look ahead gloomily to yet another day in which you just don’t feel well.

Frustratingly, researchers haven’t discovered any telltale markers during sleep that identify “unrefreshing” or “non-restorative” sleep (Wilkinson & Shapiro, 2012).

Given how big a problem unrefreshing sleep is, it is unsurprising that sleep and sleep aids are among the most common topics people search for on my website. Many people use combinations of sleep supplements and sleep medications, hoping to wake up feeling rested and energetic, but for most, these strategies are only marginally helpful. I review some of the most common supplements and pharmacological sleep remedies in my manual Let Your Light Shine Through. And I talk about some of the pros and cons of sleep medication in a previous blogpost. This blog will focus on the supplement magnesium threonate, but first, I’d like to remind you of some sleep tips I’ve shared in the past.

2. Eight Sleep Tips

Most people I have worked with over the past 25 years feel hopeless about sleep, saying they have tried everything. Yet, in the sleep groups I ran over the past few years of my practice, learning to apply some evidence-based strategies correctly often helped. Tips like the following:

1. keeping a regular sleep routine
2. sleeping in a dark, quiet, cool environment
3. developing a calming practice like meditation before bed
4. learning and practicing cognitive behavior for insomnia strategies
5. avoiding blue light after sunset
6. avoiding foods and medication that interfere with sleep (this is very individual)
7. trying sleep supplements (like magnesium, which we will discuss further in this blogpost), and
8. talking to your health care team about sleep medications (like zopiclone, antidepressants or the new orexin-blocking drugs like lemborexant). There is a lot of negative talk about sleep medication but for those with stubborn sleep problems, they can be helpful.

If you want to learn more about these eight tips and how to apply them correctly, I offer a short self-study sleep course called Pathway 3: Sleep.

3. Why Does Magnesium Help With Sleep?

Magnesium is a mineral that acts as a necessary co-factor in hundreds of essential processes in the body. Among them, it is needed to make and regulate the neurotransmitters GABA and
glutamate and in the production of serotonin and melatonin (the sleep hormone). This is why people consider magnesium a potential sleep aid. 

To learn more about magnesium, check out my blog from April 2023 titled The Lowdown on Magnesium for Chronic Pain, ME/CFS, Fibromyalgia, and More. In it, I talk about

• the signs of magnesium deficiency,
• how to increase magnesium stores in the body,
• the different types of magnesium supplements,
• which to use for which problems, and
• the benefits of magnesium for chronic pain.

Magnesium is readily accessible, inexpensive and relatively safe. For these reasons, magnesium is widely recommended and used—just go to any website about sleep, and it is likely to be mentioned.

But if I have learned anything over my 35 years in medical practice, it is that just because everyone uses something doesn’t mean it actually works. Like so many supplements and drugs, not all studies of magnesium and sleep report benefits. It’s unclear whether the effects of magnesium in diet or in supplement form are consistent, nor what types of sleep problems and what kinds of people may benefit.

Part of the problem arises from how studies are conducted. For example, one recent longitudinal study looked at dietary magnesium intake in certain years of the study and subjective sleep reports in other years and found a “possible correlation.” I won’t mention the study here to avoid embarrassing the authors. In my opinion, data of such poor quality adds to confusion rather than clarifying a direction for people.

4. How Do We Study Sleep?

Two types of studies assess the benefits of magnesium in diet and supplements.

1. Observational studies look at what people are already doing without asking them to make any changes. These typically ask people to recall their diet over the past few days or weeks and then analyze whether there is a correlation between the amount of magnesium in the diet and some measure of sleep quality. The problem with this method is that diet is notoriously difficult to measure as most people’s memory for what they eat is less than perfect.

In addition, many spurious or just plain wrong conclusions can be drawn from observational studies. If one finds that eating more of something like magnesium is associated with a positive finding like better sleep, it is tempting to assume that magnesium is causal, meaning that it contributes to better sleep and that taking more of it as a supplement is worth trying. But there are problems with this assumption.

• It could be that the positive finding (better sleep) is a result of the behavior (eating a magnesium-rich diet).
• Alternatively, it could be that people who sleep better have more energy to prepare a healthy diet rich in magnesium-containing green leafy vegetables,whole grains, nuts, and legumes, some of the rich sources of magnesium. If this is the case, then the increased magnesium intake results from better sleep rather than being the cause.
• It could also be that another variable not measured in the study accounts for both the healthy diet and the better sleep. Common examples of this include the reality that people who have more financial means have the ability to purchase more vegetables and to afford better accommodations that are conducive to restful sleep.

2. Most researchers prefer placebo-controlled clinical trials to avoid some of the common problems of population-based studies. In a clinical trial, researchers attempt to keep most other variables constant and change only the one being tested, in this case, how much magnesium is being ingested. Most clinical trials look at magnesium supplementation rather than dietary magnesium because it is easier to establish whether someone takes a capsule. 

The highest level of evidence in sleep trials is to give an intervention and then use objective measures like the gold-standard overnight sleep study to see if it is helping. However, polysomnography is a very expensive test, and few researchers have the capacity to use it, especially for the large numbers of participants needed to feel confident about a study’s results.

5. How Much Does Magnesium Improve Sleep?

In this section, I share the results of some studies assessing whether magnesium in the diet and magnesium supplementation benefit sleep. Several studies were summarized in a recent systematic review, which makes my job easier. The findings are hopeful but not conclusive (Arab, Rafie, Amani, & Shirani, 2023).

A population-based study of 3262 Turkish adults aged between 20 and 64 years found a correlation between higher dietary intake of Mg and better sleep quality. Another study of 3304 young female Japanese dietetics students found that those with higher magnesium intake from the diet had an earlier sleep window than those consuming less magnesium.

So, the population-based studies suggest that a diet higher in magnesium is helpful for sleep. What about clinical trials?

In one of the few trials with objective markers, 500 mg of elemental magnesium supplementation in elderly adults with insomnia led to increased sleep time and efficiency, melatonin and decreased cortisol levels. These are helpful shifts in biology that assist sleep. One wants melatonin levels to be high and cortisol levels to be low at night. A strength of this study is that the dietary magnesium intake was also measured and did not differ between the intervention and control groups (Abbasi et al., 2012).

However, not all clinical trial results have been positive. 

A study of older adults with sleep problems associated with leg cramps reported no subjective improvement in sleep and cramping in the group taking 900 mg/day of magnesium citrate. This is bad news for those of us suffering from leg cramps, a problem that increases with age. In another clinical trial of 100 older adults with poor sleep, supplementation with 320 mg of magnesium citrate per day had no effect on sleep. Why might this be? Is it that magnesium taken in the diet is more effective than when taken as a stand-alone supplement? Is it that the types of magnesium tested (mostly magnesium citrate) aren’t the best type to use for sleep? Or could it be that the dose is insufficient to benefit sleep? So many questions.

6. Why Might Magnesium Threonate Be Better?

It is possible that the mixed results are because different studies use different types of magnesium, not always those that are best absorbed. To benefit sleep, the magnesium must reach the brain. But the amount of magnesium in the brain is tightly controlled and hard to increase.

In 2010, a group from MIT reported on the benefits of a novel form of magnesium called magnesium threonate. Threonate is a derivative of vitamin C. When combined with magnesium, the threonate helps the magnesium cross the blood-brain barrier. When magnesium threonate was given orally to rats, magnesium concentration in the brain increased. This, in turn, led to increased neuroplasticity and improved cognitive function in both young and older rats (Slutsky et al., 2010).

The Slutsky publication led to considerable interest in this new form of magnesium, and several clinical trials have since been published suggesting that magnesium threonate might be better than other forms of magnesium at improving brain functions such as thinking and sleeping. Before sharing a couple of these studies with you, I need to mention a significant weakness of the research on magnesium threonate. Most of the studies are of a particular proprietary brand called Magtein® and the company that manufactures it funds them. This means that the results must be taken with caution.

One of these industry-sponsored studies was reported in 2022, looking at the benefits of magnesium threonate in 40-something-year-old Chinese adults. The research team tested magnesium theronate 1.6 mg/day in combination with phosphatidylserine, vitamins B6, C and D3. They reported significant improvement in 5/5 memory tests after only 30 days. 

Phosphatidylserine is a fatty component of cell membranes that supports cognitive function. B6, vitamin C and vitamin D3 all increase magnesium absorption and function. These ingredients are proposed to work synergistically to result in the impressive benefit reported (Zhang et al., 2022). 

So, what about sleep? A recently published trial of middle-aged adults with self-reported sleep problems reported that taking magnesium threonate 1 g per night led to improved Oura ring measures, including REM sleep, deep sleep, and readiness (a measure of heart rate variability) as well as subjective measures of daytime mood, energy and productivity. This is encouraging because it was a controlled trial and used objective measures. A weakness of this study is that they looked at so many measures that some would be expected to be positive by chance alone (Hausenblas et al., 2024).

Magnesium threonate has been the darling of the nutritional supplement field for several years. It is currently being tested for benefits in animal models of oxidative stress to see whether it might be protective against dementia. Despite some early studies suggesting benefits in humans, a 2024 meta-analysis reports that the data is too inconsistent to conclude whether magnesium of any kind improves human cognitive health (Chen et al., 2024).

7. My Personal Experience With Magnesium Threonate

As many of you know, I tend to try most things myself before writing about them or recommending them to the community. Several years ago, once I got my mind around the hefty price tag of this proprietary supplement and tried magnesium theronate (the brand used in the research studies and the recommended dose for 3 months), I didn’t notice any effect—no change in sleep, leg cramps or any other symptom.

Since I tried it, the price has come down, but magnesium threonate is still much higher than other forms of magnesium. Expect to pay about $28 - $45+ CAD for 90 capsules. You need to take three capsules a day to get the 150 mg of elemental magnesium recommended for cognitive or sleep benefits.

8. Conclusions

Magnesium is a very important mineral in our bodies, facilitating over 300 biochemical processes. Getting enough magnesium is important and sometimes challenging, given the poor nutritional composition of the average North American diet and multiple barriers to absorption.

Among the most important functions of magnesium are those that could facilitate sleep by increasing GABA and melatonin levels.

Although magnesium supplements are widely used, whether they improve sleep remains unclear. There is definitely a signal of benefit, but how much and for whom remains to be determined. Given the relatively low cost and high safety margin, magnesium is worth a try. The worst that can happen is some loose stools if you take a bit too much for your body.

Magnesium threonate, especially in combination with molecules that help it get to the brain and do its job, may be a better choice if you can afford the increased price tag. If you have tried magnesium threonate, I would love to hear your experience. Does it live up to the hype?

References

Abbasi, B., Kimiagar, M., Sadeghniiat, K., Shirazi, M. M., Hedayati, M., & Rashidkhani, B. (2012). The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial. J Res Med Sci, 17(12), 1161-1169.

Arab, A., Rafie, N., Amani, R., & Shirani, F. (2023). The Role of Magnesium in Sleep Health: a Systematic Review of Available Literature. Biol Trace Elem Res, 201(1), 121-128. doi: 10.1007/s12011-022-03162-1

Chen, F., Wang, J., Cheng, Y., Li, R., Wang, Y., Chen, Y., . . . Tucker, K. L. (2024). Magnesium and Cognitive Health in Adults: A Systematic Review and Meta-Analysis. Advances in Nutrition, 15(8), 100272.  doi: https://doi.org/10.1016/j.advnut.2024.100272

Hausenblas, H. A., Lynch, T., Hooper, S., Shrestha, A., Rosendale, D., & Gu, J. (2024). Magnesium-L- threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: A randomized controlled trial. Sleep Med X, 8, 100121. doi: 10.1016/j.sleepx.2024.100121

Slutsky, I., Abumaria, N., Wu, L.-J., Huang, C., Zhang, L., Li, B., . . . Liu, G. (2010). Enhancement of Learning and Memory by Elevating Brain Magnesium. Neuron, 65(2), 165-177. doi:10.1016/j.neuron.2009.12.026

Wilkinson, K., Shapiro, C. (2012). Nonrestorative sleep: symptom or unique diagnostic entity? Sleep Med, 13(6), 561-569. https://doi.org/10.1016/j.sleep.2012.02.002

Zhang, C., Hu, Q., Li, S., Dai, F., Qian, W., Hewlings, S., . . . Wang, Y. (2022). A Magtein(®), Magnesium L- Threonate, -Based Formula Improves Brain Cognitive Functions in Healthy Chinese Adults. Nutrients, 14(24). doi:10.3390/nu14245235