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Not all magnesiums are equal: organic forms such as magnesium glycinate and magnesium citrate dissolve better and are more easily absorbed by the digestive tract than inorganic forms such as magnesium oxide. When you compare products, check the form first and the elemental magnesium second, because the big number on the front is often the weight of the whole compound, not the magnesium inside it.

If you've ever stood in the supplement aisle, or scrolled at 2am, wondering why one magnesium says 1.5 g and another says 175 mg, this guide is for you. We'll walk through the main types of magnesium, how to read a label, whether powder or tablets suit you better, and where glycine fits in.

Before you add any magnesium supplement: 350 mg a day is the upper level. Australia's upper level of intake for magnesium from supplements is 350 mg a day for adults. Food doesn't count toward it. If you take more than one product with magnesium, add up the elemental amounts, and talk to your pharmacist or doctor before you go over it (NHMRC Nutrient Reference Values).

Why the type of magnesium matters

Magnesium is a mineral your body needs for many everyday processes, and most adult women need about 310 to 320 mg a day (Healthdirect). Much of that can come from food: green leafy vegetables, legumes, nuts, seeds and wholegrains.

In a supplement, magnesium never sits in the jar on its own. It's always bound to a partner molecule, and that partner changes two things:

• How much actual magnesium you get per gram.
• How readily it dissolves and is absorbed.

That's why two products can both say “magnesium” on the front and be quite different inside.

Organic vs inorganic magnesium, in plain English

“Organic” here is a chemistry word, not a farming one. It means the magnesium is bound to a carbon-based partner, such as an amino acid (glycinate) or a fruit acid (citrate). Inorganic forms, such as magnesium oxide, are bound to a simple mineral partner.

Organic forms such as glycinate and citrate dissolve better and are more easily absorbed by the digestive tract than inorganic forms such as oxide. In a randomised, double-blind study of 46 healthy adults taking 300 mg of elemental magnesium a day for 60 days, the organic forms (citrate and an amino acid chelate) showed greater absorption than magnesium oxide (Walker et al., 2003). An earlier study found magnesium oxide barely dissolved in water, while magnesium citrate dissolved well and was better absorbed (Lindberg et al., 1990).

Magnesium glycinate vs citrate vs oxide at a glance

Percentages are approximate and vary with the exact compound and how much water is bound in it. That's exactly why the elemental figure on the label matters.

Magnesium glycinate

Magnesium glycinate is magnesium bound to glycine. You'll also see it called magnesium bisglycinate or magnesium glycinate chelate. “Bisglycinate” is the more precise chemical name: two glycine molecules for every magnesium. It's one of the most searched forms of magnesium in Australia, and one of the organic forms that dissolves better and is more easily absorbed than oxide.

Magnesium citrate

Magnesium citrate is magnesium bound to citric acid. It dissolves readily in water, which is one reason it turns up in powders and drink mixes. It's also sold on its own as a short-term laxative (MedlinePlus), which is where its reputation comes from. Like every form, too much at once can upset your tummy: Healthdirect lists diarrhoea, nausea and abdominal cramps as signs of too much supplemental magnesium.

Magnesium oxide

Magnesium oxide is an inorganic form with a lot of magnesium per gram, so a small tablet can carry a big number. It barely dissolves in water, though, and it's absorbed less readily than the organic forms. It isn't a “bad” ingredient. It simply means the headline number doesn't tell you the whole story.

Other types of magnesium you'll see

You'll also find threonate, malate, chloride, aspartate, taurate and orotate on the shelf. Each has its own partner molecule and its own magnesium percentage. The same two questions apply to every one: what's it bound to, and how much elemental magnesium is in a serve?

How to read a magnesium label: elemental vs compound weight

Elemental magnesium is the amount of actual magnesium in a serve. The compound weight is the magnesium plus its partner molecule. Always compare products on elemental magnesium.

Here's a real example. A label might list “magnesium glycinate dihydrate 1.5 g”. That's the weight of the whole compound. The magnesium inside it is about 175 mg. The rest is the glycine partner and water bound into the compound.

Four things to check on any magnesium label:

1. The form. Glycinate, bisglycinate, citrate, oxide or something else.
2. The elemental figure. Look for “equivalent to magnesium” or “elemental magnesium”.
3. Per what? Is the number per tablet, per two tablets, or per scoop?
4. Everything else you take. Multivitamins, sleep formulas, muscle formulas, antacids and laxatives often contain magnesium too. Add them up.

How much magnesium is too much?

Australia's Nutrient Reference Values set an upper level of 350 mg of magnesium a day from supplements for adults. This limit is for supplements only, not magnesium from food (NHMRC Nutrient Reference Values).

If you take more than one product with magnesium, add up the elemental amounts. Your pharmacist can help you check the total.

Is magnesium powder better than tablets?

The form matters more than the format. A tablet of a form that dissolves well will be absorbed more readily than a powder of a form that barely dissolves. That said, powder has some practical pluses, and so do tablets.

The bulk point is the one many people don't realise. Because glycinate and citrate are only about 11 to 16% magnesium, getting 350 mg of magnesium from them takes roughly 2 to 3 g of compound. In capsules, that usually means several. In a powder, it fits in one serve.

The best format is the one you'll take consistently, as directed on the label.

Where glycine fits in

Magnesium glycinate and glycine aren't the same thing. Glycinate is made during manufacturing, when magnesium is chemically bound to glycine. If you take magnesium and glycine separately, they don't combine in your body to make magnesium glycinate.

Glycine is an amino acid, and in supplements it's usually measured in grams rather than milligrams. Your body makes it, and you also get it from protein foods.

So if a label lists glycine as its own ingredient, that's separate from the glycine already bound inside the magnesium glycinate.

Which magnesium should you choose?

There's no single “best” magnesium for everyone. A good starting point is an organic form such as glycinate or citrate, a clear elemental dose that keeps your supplement total within 350 mg a day, and a format you'll actually take each night.

Research on magnesium on its own and sleep is still developing. A 2026 systematic review by Australian researchers found the results so far are inconsistent, and the certainty of the evidence is low to very low (Lopresti et al., 2026). That's one more reason to read the whole label, so you know exactly what you're taking and how much.

If your sleep has changed and it's affecting your days, talk to your GP. They can check what's going on, including your magnesium levels.

Why SleepSHAKE Midnight Berry uses magnesium glycinate and citrate

SleepSHAKE Midnight Berry is a light berry drink you shake into cold water before bed. We chose two organic forms of magnesium for it: magnesium glycinate and magnesium citrate, giving 350 mg of elemental magnesium in each 10 g serve.

Each serve also contains 3 g of glycine as a separate ingredient, plus reishi, Chamomile with Apigenin and ashwagandha. Every active is at the dose on the label.

Why glycinate and citrate together

• The split: 175 mg + 175 mg. Magnesium glycinate 1.5 g gives about 175 mg of magnesium. Magnesium citrate 1.2 g gives about 175 mg. Together, that's 350 mg per serve.
• Both are organic forms. Organic forms such as glycinate and citrate dissolve better and are more easily absorbed by the digestive tract than inorganic forms such as oxide. That doesn't make other forms useless. Oxide carries more magnesium per gram, and every form has its place; it's simply a different choice.
• Both suit a drink. Citrate dissolves readily in water (Lindberg et al., 1990), and a powder makes a full 350 mg dose of bulky organic forms practical without a handful of capsules.
• About citrate's reputation. Magnesium citrate is also sold on its own as a short-term laxative. In SleepSHAKE, citrate provides half the magnesium (175 mg), and the whole serve stays at 350 mg, the upper level for supplements. As with any magnesium, taking more than directed can cause diarrhoea, so take one serve as the label directs.

One serve is 350 mg of magnesium, the Australian upper level for supplements. Please don't add another magnesium supplement on top of SleepSHAKE without advice from your pharmacist or doctor. Check multivitamins and muscle formulas too.

What SleepSHAKE Midnight Berry does:

• Enhances sleep quality and increases deep sleep
• Promotes refreshing sleep
• Supports nervous system function
• Enhances muscle relaxation
• Helps reduce occurrence of muscle cramp
• Helps relieve mild muscle twitches
• Contains reishi, traditionally used in Chinese medicine to calm the mind

Your nightly ritual: add 2 scoops (10 g) to 100 to 250 mL of cold water (use the lesser amount of water if you like, as long as you take the full 2 scoops), shake well and drink it straight away, 30 minutes before bed.

SleepSHAKE is listed on the ARTG (AUST L 524569). That means it's a listed medicine, held to the standard the Therapeutic Goods Administration sets for what goes in it, how it's made, and what we're allowed to say about it.

Made in Australia. Melatonin free. No added sugar. Contains sulphites. For adults only.

See what's in SleepSHAKE Midnight Berry

Always read the label and follow the directions for use. Use only as directed. If symptoms persist, talk to your health professional. If you take medication, or are pregnant or breastfeeding, talk to your health professional before use.

Keep reading

• What are the best natural sleep supplement ingredients? A plain English guide
• How long does it take for a sleep supplement to work?
• Sleep hygiene vs sleep supplements: do you need both?

Frequently asked questions

What's the difference between magnesium glycinate and magnesium citrate?

Magnesium glycinate is magnesium bound to glycine, an amino acid. Magnesium citrate is magnesium bound to citric acid. Both are organic forms that dissolve better and are more easily absorbed by the digestive tract than inorganic forms such as magnesium oxide, and both carry a similar amount of magnesium by weight.

Can you take magnesium glycinate and citrate together?

Yes. Many formulas combine the two. What matters is the total elemental magnesium from all your supplements. Australia's upper level for adults is 350 mg a day from supplements, so add up everything you take and check with your pharmacist or GP if you're unsure.

Is magnesium citrate OK to take at night?

With magnesium citrate, the dose matters more than the time of day. Magnesium citrate is also sold on its own as a short-term laxative, so stick to the dose on your product's label: as with any magnesium, too much can cause diarrhoea, nausea and tummy cramps. Keep your total magnesium from supplements within 350 mg a day.

Can I take SleepSHAKE with another magnesium supplement?

Not without advice from your pharmacist or doctor. One serve of SleepSHAKE Midnight Berry provides 350 mg of magnesium (175 mg from glycinate and 175 mg from citrate), which is the Australian upper level of intake for magnesium from supplements for adults. Check multivitamins, muscle formulas, antacids and laxatives too.

Is magnesium glycinate the same as magnesium bisglycinate?

On most labels, they describe the same thing: magnesium bound to glycine. “Bisglycinate” is the more precise chemical name, meaning two glycine molecules for each magnesium. Either way, check the elemental magnesium per serve.

Is magnesium oxide a bad form of magnesium?

It isn't bad, it's different. Magnesium oxide contains a lot of magnesium per gram, but it barely dissolves in water and is absorbed less readily than organic forms such as glycinate and citrate. A high number on an oxide label doesn't mean you absorb more.

Is magnesium powder better than tablets?

The form matters more than the format. Powder is easier when you want a full dose of a bulky organic form without swallowing several capsules, and it's already dissolved when you drink it. Tablets are easier to travel with. Choose the one you'll take consistently.

How do I know how much magnesium is in my supplement?

Look for the elemental magnesium, often written as “equivalent to magnesium” on the label. The larger number next to the compound name, such as magnesium glycinate 1.5 g, is the weight of the whole compound, not the magnesium inside it.

Do magnesium and glycine combine in the body to make magnesium glycinate?

No. Magnesium glycinate is made during manufacturing, when magnesium is chemically bound to glycine. If you take magnesium and glycine as separate ingredients, they don't combine in your body to form magnesium glycinate.

When is the best time to take magnesium?

Follow the directions on your product's label. Night-time formulas are usually taken in the evening. SleepSHAKE Midnight Berry is taken 30 minutes before bed: 2 scoops (10 g) in cold water, shaken and drunk straight away.

About the author

Dominique McAdam is the co-founder of LifeLab&Co, the Australian company behind SleepSHAKE Midnight Berry.

Sources

1. Healthdirect Australia. Magnesium. healthdirect.gov.au/magnesium
2. National Health and Medical Research Council (NHMRC) and NZ Ministry of Health. Nutrient Reference Values for Australia and New Zealand: Magnesium. eatforhealth.gov.au
3. Walker AF, Marakis G, Christie S, Byng M. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnesium Research, 2003;16(3):183-91. PubMed
4. Lindberg JS, Zobitz MM, Poindexter JR, Pak CY. Magnesium bioavailability from magnesium citrate and magnesium oxide. Journal of the American College of Nutrition, 1990;9(1):48-55. PubMed
5. MedlinePlus (US National Library of Medicine). Magnesium citrate. medlineplus.gov
6. Lopresti AL, Smith SJ, Drummond PD. Magnesium supplementation for sleep in adults: a systematic review of randomized controlled trials. Journal of Dietary Supplements, 2026;23(5):553-581. PubMed