Magnesium for sleep: does it help, and which kind should you take?

Magnesium is having a moment. Scroll for long enough and someone will tell you a magnesium glycinate capsule before bed changed their sleep for good. So does magnesium actually help you sleep, and if you want to try it, which kind and when?

Here is what the research says, how much magnesium you need, where to get it from food, who should check first, and how the Thrive Health Band and the Thrive by Optihealth app can show you whether it makes any difference to your own nights.

What does magnesium do?

Magnesium is a mineral your body uses in more than 300 processes, including how your muscles and nerves work, your energy and your heart rhythm. It's also involved in how your body winds down. It plays a part in GABA, a brain chemical linked with relaxation, and may affect melatonin, the hormone that helps time your sleep.

That's why it gets talked about as a sleep helper. But "involved in sleep" isn't the same as "a supplement will make you sleep better".

Does magnesium help you sleep?

Honestly, the evidence is limited and mixed.

A 2021 review of small trials in older adults with insomnia found low-certainty evidence that magnesium might help people fall asleep a little faster.
Harvard Health notes that trials so far haven't shown a consistent benefit, and there's no solid proof magnesium helps you stay asleep.
Australia's pharmacists list magnesium among the complementary medicines sometimes used to aid sleep, while noting good evidence is lacking.

So it may help some people a little, especially if they don't get much magnesium from food. It's unlikely to fix poor sleep on its own, and it isn't a replacement for working out what's keeping you awake.

Magnesium glycinate vs other types

Supplements come in different forms. The ones you'll see most on the shelf are:

Magnesium glycinate (or bisglycinate): magnesium bound to glycine. Popular for sleep and often described as gentler on the stomach.
Magnesium citrate: well absorbed, but more likely to loosen your bowels.
Magnesium oxide: common and cheap, absorbed less well, and more likely to upset your tummy.
Magnesium threonate: marketed for the brain and sleep. A recent trial found people reported sleeping better, but their measured sleep didn't change.

There's no strong research showing one form is best for sleep. If you try one, glycinate is a reasonable, gentle choice, but check the label for how much actual (elemental) magnesium each dose gives you.

How much magnesium do you need a day?

Australia's Nutrient Reference Values recommend a total daily intake of:

Men: 400 mg a day (19 to 30) and 420 mg a day (31 and over)
Women: 310 mg a day (19 to 30) and 320 mg a day (31 and over)

For supplements, the upper level for adults is 350 mg a day on top of food. Above that, diarrhoea, nausea and cramps become more likely.

Foods high in magnesium

Food is the easiest place to start, and it comes with fibre and other nutrients too:

nuts and seeds, such as almonds, cashews and pumpkin seeds
legumes, such as beans, chickpeas and lentils
wholegrains, such as oats and brown rice
leafy greens, such as spinach
dark chocolate, bananas and avocado

When is the best time to take magnesium?

There's no proven best time. If you're trying it for sleep, taking it in the evening makes sense, and having it with food can be easier on your stomach. Taking it at a similar time each day matters more than the exact hour.

Who should check first

Talk to your GP or pharmacist before you start if you have kidney problems, are pregnant or breastfeeding, or take regular medicines. Magnesium can interact with some antibiotics, thyroid medicine, osteoporosis medicines and diuretics.

Sleep basics still come first

Before reaching for a supplement, the everyday basics tend to make the biggest difference: regular sleep and wake times, morning light, caffeine earlier in the day and less alcohol close to bed. See how to fall asleep faster and sleep hygiene basics.

See if magnesium changes your sleep with Thrive

The fairest way to know whether magnesium helps you is to look at your own nights before and after.

Wear the Thrive Health Band day and night. It has no screen, so it's comfortable in bed, and up to 14 days of battery means fewer nights lost to charging. In the Thrive by Optihealth app, Sleep shows how long you slept, your sleep stages and your deep, light and awake time, with week and month views to compare. Overnight the Band also tracks resting heart rate, HRV and temperature.

Add magnesium in Medications & Supplements, with the amount, how often and the time you take it, and tag Supplements in your Daily Check-In. Over time, Thrive learns what is usual for you right across your health, from sleep, heart and activity to mood, energy, stress, meals, medications and more. So rather than comparing you with an average, it can show whether your nights look different since you started.

Give it a few weeks, then ask Ask Thrive things like:

"Has my sleep changed since I started magnesium?"
"Do I wake less on nights I take it?"

If you're working on your sleep with someone, Thrive Loops lets you share selected information with a participating trainer, health professional or someone you trust. You decide what to share and with whom, and you can change or revoke access at any time.

When to talk to your GP

If you have trouble getting to sleep or staying asleep most nights for more than a few weeks, or you feel tired most days, book in with your GP. For ongoing insomnia, a talking therapy called CBT-I is the recommended first approach, and your GP can help you access it. Thrive isn't a diagnosis, but your sleep trends, supplements and medications are all in the app. Ask Thrive can help you pull together what changed and when, and you can show your Thrive trends to your GP.

Before you buy

You'll need a compatible iPhone or Android phone, because the Thrive app is on the Apple App Store and Google Play, in Australia and eight other countries. The app stores are only for downloading the app, though; they aren't where you buy the Band or a Plan. You can buy at thrivehealthband.com, or at a participating World Gym Australia location or health and wellness clinic.

The Thrive Health Band is A$660 for the first year under the launch offer. That includes the Band, which is yours to keep, and 12 months of the Thrive by Optihealth app, My Health on the web, Health Fingerprint, Ask Thrive, Thrive Loops and your data, paid once upfront. Prices are in AUD and include GST. Free Australia-wide shipping during the launch offer (usually A$14.99).

Nothing renews automatically. After your first year, you can get a new band plus 12 more months for A$660, or keep your band and renew the Thrive Connected Plan for A$240 a year, or A$29 a month with no lock-in.

You're also covered by a 12-month Thrive Care Warranty, and consumer guarantees under Australian Consumer Law always apply. See Returns if something is wrong with your purchase.

Common questions

Can I take magnesium every night?

For healthy adults, staying within the 350 mg supplement upper level is generally considered safe long term. Check with your GP or pharmacist if you have kidney problems or take other medicines.

Is magnesium the same as melatonin?

No. Melatonin is a hormone, and in Australia it is only available from a pharmacist or on prescription. Magnesium is a mineral.

Does magnesium help with leg cramps at night?

It's a common reason people take it, but research hasn't shown much benefit for everyday night cramps. If cramps are frequent, talk to your GP.

For more answers, see Questions.