Magnesium L-Threonate and Its Effects on Sleep Quality

Magnesium L-Threonate and Its Effects on Sleep Quality

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Good health is essential for a good life, but there are many pressures from every angle pushing us towards less healthy lifestyles. Whether it's processed foods, a sedentary desk job, or long hours preventing us from sleeping, it's a lot to fight against. That's why whenever a supplement or medication shows promise, even the most meager hint is often picked up and carried through thousands of exciting blog posts for the Next Big Breakthrough in health.

The three core pillars of great health are diet, exercise, and good sleep, and by far, the hardest of these to maintain is sleep. After all, it's not like you can practice sleeping or make adjustments to your sleep while you're asleep. So, whenever there's something like a breakthrough for better sleep, I'm interested.

Now, I'm obviously not one to avoid supplements out of hand, but neither am I one to chase them based on hype and threadbare evidence. I try to be transparent about what I take and why. So, when I saw a bunch of health influencers start to promote a new supplement for better sleep, I was interested.

The question is, is it any good, and should you consider taking it?

Introducing Magnesium L-Threonate

The supplement in question today is Magnesium L-Threonate.

Magnesium in general is an essential mineral, which means it's not synthesized by the body out of ingredients you consume, and must be ingested from dietary or supplementary sources. It's used in over 300 different enzyme reactions and processes throughout the body, from assisting with muscle and nerve function to regulating blood sugar to wound healing.

The recommended daily intake of magnesium ranges from 240mg for pre-teens to 300-400 mg for adults. For most people, you'll get plenty of magnesium through your diet. Healthy foods like whole grains, legumes, nuts, seeds, and leafy greens are generally high in magnesium.

Similarly, many modern processed foods like fortified cereals are fortified with additional essential nutrients, including magnesium.

Magnesium L-Threonate

Despite being present in many fortified foods and natural sources, many people around the world may not be getting as much magnesium as their bodies need. However, magnesium is present in many dietary supplements and combination supplements – including the multivitamin I take – so it's not hard to get from additional sources.

Magnesium comes in many different forms. Magnesium citrate, for example, is commonly used as a laxative because of its effects on drawing moisture to the intestines, softening stool, and facilitating bowel movements. Magnesium Glycinate is a form of magnesium bound to an amino acid, glycine, and is often recommended as a sleep aid and supplement for migraines. Magnesium oxide is frequently used as a general magnesium supplement as it’s cheap and has a high elemental magnesium percentage.

What is Magnesium L-Threonate? Well, Threonic Acid is a metabolite of Vitamin C, making magnesium l-threonate a compound designed to make magnesium more bioavailable. Some research indicates that, out of the various common forms of magnesium, magnesium l-threonate may be the most readily bioavailable version, at least in animal studies. This added form of supplementary magnesium is purported to have a variety of benefits, from cognitive health to sleep quality to anti-anxiety and more.

Why is Magnesium L-Threonate Popular?

I'm unclear on exactly who first started hyping up magnesium l-threonate.

Like many supplements, it's developed, it hits the market, and the ecosystem of health influencers picks it up and runs with it, saturating the markets with blog posts and "research" that has been filtered through the endless game of telephone we all sort through every day. The end result is posts – and store listings – from videos, posts on Reddit and social networks, and informative posts on sites like Healthline.

Popularity of Magnesium L Threonate

As with most supplements, there's some evidence that suggests magnesium l-threonate may be beneficial in some capacity. In most cases, the evidence comes from small-scale animal studies, and relatively little human research has been performed to date.


What Do the Studies Say?

I always like to dig into the primary studies and research for any supplement I see circulating around the internet, especially when it could potentially be beneficial for one of the three core pillars of overall health. Since sleep is so deeply important, anything that can promote better sleep can be a great idea if it works.

The question is, what does the literature say? There are a few prominent studies worth discussing:

An Iranian study performed on a group of 46 individuals tracked several measures of sleep quality across a randomized, placebo-controlled, double-blind study. Across the participants, a small but statistically-relevant increase in sleep measures was shown. However, this study was performed using elemental magnesium supplements, not specifically magnesium l-threonate. It shows that some forms of magnesium can have some impact on sleep, which is a good sign for the supplement, but the effects were limited and most beneficial for elderly individuals. And, of course, with less than 50 participants, it's hard to say how reflective the impacts are of the greater population.

Magnesium L Threonate

A Chinese study was much larger, with 3,964 participants, though the study itself wasn't focused on sleep or on magnesium specifically. This was additional data taken from a large study called CARDIA, the Coronary Artery Risk Development in Young Adults study, which was performed beginning in 1985. While the data was taken in a reputable fashion, and the length, number of participants, and detail of the study are all very good, it's still a secondary conclusion from a study that wasn't focused on either magnesium or sleep. Still, it does show some correlation between magnesium intake and sleep quality. Again, it's not specifically about magnesium l-threonate either, and as we all know, different forms of the same molecule can have very different effects.

Another Chinese study, this time specifically about magnesium l-threonate, showed some cognitive improvement in adults taking the specific supplement and participating in the standardized Clinical Memory Test. This study shows that magnesium l-threonate is well absorbed and has some impact, but it does nothing to study its effects on sleep.

A research review on magnesium and sleep specifically focuses on restless leg syndrome. Of over 850 studies about magnesium and/or restless leg syndrome, the vast majority were excluded on relevancy grounds, and only eight studies covered all of the bases well enough to be reviewed. The results were inconclusive and didn't show enough of a benefit to say whether or not magnesium would help.

A similar review and meta-analysis of magnesium for general sleep quality found some small benefits to sleep onset latency (the time it takes to fall asleep), total sleep time, and other small benefits. However, they note that all of the trials they found to review were of moderate to high risk of bias, had relatively small amounts of benefits, and were not well-supported by quality evidence. Note that this doesn't mean magnesium doesn't work; it's just that the quality of the studies they reviewed was lacking.

Finally, there's always the anecdotal evidence. Some people report magnesium l-threonate causing insomnia or disruptive dreams. Others use it as a daytime supplement for focus rather than a nighttime supplement for sleep. Yet others report beneficial effects for sleep, usually in combination with other more intense medications. This kind of evidence isn't usually something to rely on, though; the lack of controlled study is far too large to ignore.

Is it Worth Taking Magnesium L-threonate for Sleep?

When you review the literature, it's hard to say whether or not magnesium is truly beneficial for sleep, no matter the form. Some animal studies and some studies in people have shown small benefits, but at the same time, the overall body of evidence is lacking.

As is so often the case with supplements, the answer likely falls somewhere in the middle. Magnesium is not a miracle drug for vastly improved sleep. In some people – especially those with chronically low magnesium already – it may have some beneficial effects, but not enough to be fully recommended by medical professionals for this purpose.

Taking it For Sleep

Is it worth trying it out? That's up to you and your doctor.

Generally, with any supplement like this, you need to be aware of three things.

#1 is the quality, purity, and form of the supplement. Magnesium l-threonate is a bioavailable form of magnesium and, by all accounts, readily available, but it's also something you should only get from reputable vendors.

Quality and Purity

You don't want supplements that have been adulterated or otherwise contaminated, after all.

#2: Are there possible interactions with other medications you're already taking? ConsumerLab reports indicate that magnesium's known effects, like some mild anticoagulant effects and its impact on blood sugar, can interact with drugs you may be taking for those purposes already.

Possible Interactions

ConsumerLab recommends at least a two-hour gap between magnesium and medications such as:

  • Some statin drugs, such as Crestor, because the antacid effects of magnesium reduce absorption of the drug.
  • Some antibiotics are used for the same reason.
  • Sotalol, a heart rhythm drug, for reduced efficacy reasons.
  • Gabapentin.
  • Levothyroxine.

In most cases, taking magnesium too close to taking another drug generally reduces the efficacy of the drug, usually because it inhibits the body's ability to break down and absorb those medications. So, if you're on any kind of medication, especially prescription medications, ask your doctor about interactions with magnesium before you start taking it in any form, l-threonate or otherwise.

#3 is potential side effects. The National Institute of Health mentions that excessive dietary magnesium does not pose a health risk – the kidneys are quite good at filtering out anything excessive – but that getting too much magnesium from dietary supplements can cause diarrhea, nausea, abdominal cramping, and other digestive troubles.

Potential Side Effects

The only records of fatal side effects are associated with extremely high doses – around 5,000 mg per day of magnesium, whereas most supplements are a small fraction of that – and are very rare. Nevertheless, the NIH recommends not to exceed 420 mg of magnesium supplements per day for men and 320 mg per day for women.

How Much Magnesium

Where do I fall in my recommendations? Roughly the same place as Dr. Colleen Lance, director of the Sleep Disorders Center at Cleveland Clinic: the evidence that it can benefit sleep is weak, but as long as you're taking reasonable doses and have cleared it with your doctor, it's unlikely to cause you any harm.

In the meantime, it would be great to see larger, better studies performed regarding the effects of magnesium l-threonate specifically, or even just magnesium in general, to see if it can have any beneficial effects on sleep quality.

Unfortunately, for the time being, the use of magnesium explicitly for the sleep benefits is more hopes and dreams than it is scientific reality.

Do you have any questions for me, or thoughts on this topic? Please share with us in the comments section! I'd love to get a constructive conversation started on this topic.


  1. Magnesium Consumer Fact Sheet from the National Institute of Health:
  2. Treatment of Magnesium L-Threonate Elevates the Magnesium Level in the Cerebrospinal Fluid and Attenuates Motor Deficits and Dopamine Neuron Loss in a Mouse Model of Parkinson's Disease:
  3. The effect of magnesium supplementation on primary insomnia in elderly:
  4. Association of magnesium intake with sleep duration and sleep quality:
  5. A Magtein Magnesium L-Threonate-Based Formula Improves Brain Cognitive Functions in Healthy Chinese Adults:
  6. Magnesium supplementation for the treatment of restless legs syndrome and periodic limb movement disorder: as systematic review:
  7. Oral magnesium supplementation for insomnia in older adults: a systematic review & meta-analysis:
  8. ConsumerLab Magnesium Report:
  9. Magnesium Healthcare Provider Fact Sheet from the National Institute of Health:
  10. Can Magnesium Supplements Really Help You Sleep? From NYT:

About Dr. Brad Stanfield

Dr Brad Stanfield

Dr. Brad Stanfield is a General Practitioner in Auckland, New Zealand, with a strong emphasis on preventative care and patient education. He runs a YouTube channel with over 240,000 subscribers, where he shares the latest clinical guidelines and research to promote long-term health. Dr. Stanfield is also involved in clinical research, having co-authored several papers, and is a Fellow of the Royal New Zealand College of General Practitioners.

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