Magnesium Threonate vs Glycinate: Which Form Should You Take?

Magnesium threonate vs glycinate comes down to your goal: choose magnesium L-threonate if your main interest is memory and mental sharpness, and choose magnesium glycinate if you want calmer evenings, better sleep and a gentle stomach at a lower price. Glycinate also delivers about twice as much elemental magnesium per gram, which matters if you are trying to close a real intake gap.

Both are good forms. Neither is magic. Below are the numbers and the studies, laid out so you can check our work.

What Magnesium Threonate and Glycinate Actually Are

Every magnesium supplement is magnesium bound to a carrier molecule. The carrier changes how well it dissolves, how your gut handles it and, possibly, where the magnesium ends up.

Magnesium L-threonate pairs magnesium with L-threonate, a compound your body makes when it breaks down vitamin C. It came out of research on brain magnesium. In rats, it raised magnesium levels in the brain and improved learning and memory (Slutsky et al., 2010). That rat work is why threonate gets sold as the "brain magnesium".

Magnesium glycinate (also sold as bisglycinate) pairs magnesium with glycine, an amino acid. It is one of the most common forms on the shelf, mostly because it is easy on the stomach. Glycine has some sleep research of its own, which we cover below. For the full rundown on this form, read our guide to magnesium glycinate for stress and sleep.

Magnesium Threonate vs Glycinate at a Glance

	Magnesium L-Threonate	Magnesium Glycinate
Elemental magnesium	About 7% by weight	About 14% by weight
Strongest evidence	Rat studies on brain magnesium, plus a few small human trials on cognition and sleep	A human trial in poor sleepers, plus general magnesium research on sleep and anxiety
Best fit	Memory and focus goals	Sleep, stress and topping up daily intake
Gut tolerance	Well tolerated in trials	Well tolerated, gentler than oxide in a small study
Cost	Higher, usually a branded ingredient	Lower, widely available
Bonus partner	L-threonate	Glycine

The Elemental Magnesium Math Most People Miss

Your body runs on elemental magnesium, the mineral itself, not the whole compound. The Supplement Facts panel lists elemental magnesium, not the weight of the full compound, according to the NIH Office of Dietary Supplements. The big number on the front of the bottle can be a different story, so read the back.

Threonate is light on magnesium. In one trial, 1 gram of magnesium L-threonate supplied about 75mg of elemental magnesium (Hausenblas et al., 2024). Another used 2 grams a day to deliver 145mg (Lopresti and Smith, 2025).

Glycinate carries about twice as much. In a recent sleep trial, 250mg of elemental magnesium came packaged with about 1.5 grams of glycine (Schuster et al., 2025). That works out to roughly 14% magnesium by weight.

Why this matters: adult women need 310 to 320mg of magnesium a day and adult men 400 to 420mg. US survey data show 48% of Americans get less than they need from food (NIH ODS). If you are plugging a gap, threonate takes a lot of powder to deliver a modest dose.

Magnesium L-Threonate vs Glycinate for the Brain

The case for threonate starts in animals. Rats given it had higher brain magnesium, more synapses in the memory regions of the hippocampus and better scores on learning and memory tasks (Slutsky et al., 2010). Promising. Also rats.

The human trials are small, and the ones below were funded by or run with the makers of the branded ingredient. That does not make them wrong. It does mean you want more of them before you get excited.

• In 44 adults aged 50 to 70 with cognitive impairment, a threonate-based formula improved an overall cognition score versus placebo over 12 weeks (Liu et al., 2016). Effects on sleep and anxiety could not be judged because the placebo group improved too.
• In 100 adults aged 18 to 45 with poor sleep, 2 grams a day for six weeks improved a composite cognition score and reaction time compared with placebo. Self-rated sleep impairment improved, but sleep measured by a wearable ring did not (Lopresti and Smith, 2025).

Glycinate has no comparable brain-specific trials. So if memory is your main goal, threonate has the more targeted evidence, early as it is. For how magnesium fits into foggy, slow-thinking days more broadly, see our guide to magnesium for brain fog.

Which Magnesium for Sleep and Anxiety

Both forms have sleep data. The results are encouraging rather than dramatic.

Glycinate. In 155 adults reporting poor sleep, 250mg of elemental magnesium as bisglycinate lowered insomnia scores more than placebo over four weeks (Schuster et al., 2025). The effect was small. People who ate less magnesium to begin with seemed to benefit more.

The glycine adds a little to the story. In sleep-restricted volunteers, 3 grams of glycine before bed reduced next-day fatigue and improved a reaction-time test (Bannai et al., 2012). A normal glycinate dose gives you less glycine than that, so treat it as a bonus, not the headline.

Threonate. In 80 adults aged 35 to 55 with sleep complaints, 1 gram a day for three weeks improved deep and REM sleep scores on a wearable ring, plus self-rated mood, energy and alertness, compared with placebo (Hausenblas et al., 2024).

Neither form will override a wired evening, a late coffee or a phone in bed. If stress hormones are keeping you up, our piece on cortisol and sleep covers that side.

Anxiety. Here the research is about magnesium broadly, not one form. A systematic review of 18 studies found magnesium looked helpful for subjective anxiety in people already prone to it, but rated the evidence as poor quality (Boyle et al., 2017). No trial has compared threonate and glycinate head to head for stress. Glycinate is the usual pick because it is gentle, affordable and gives you more magnesium per dose. More in our deep dive on magnesium for anxiety.

Magnesium Threonate vs Glycinate: Which Should You Pick?

Start with your gut. High doses of some forms cause diarrhea, and NIH ODS names carbonate, chloride, gluconate and oxide as the usual culprits. In a small trial in people who had part of their bowel removed, glycinate was absorbed about as well as oxide overall and was better tolerated (Schuette et al., 1994). Threonate was well tolerated in its trials too.

Then your wallet. Threonate is usually sold as a branded ingredient and needs more powder per milligram of magnesium, so it tends to cost more per day. Glycinate is cheap and everywhere. Do the price-per-day math yourself before you commit.

• Pick threonate if memory and mental sharpness are the goal, your diet already covers the basics and the price does not bother you.
• Pick glycinate if you want better sleep, a calmer evening or a gentle way to top up a low intake.
• Use both if you want threonate for the brain angle and glycinate to reach your total. Keep supplemental magnesium within the adult upper limit of 350mg a day unless your doctor says otherwise.

Two safety notes. If you have kidney disease, talk to your doctor before taking any magnesium supplement, because your kidneys may not clear the extra. If you are pregnant or breastfeeding, check with your doctor first.

Why We Use Glycinate (Weigh This Section Accordingly)

Full disclosure: we make CALM+COLLECTED, and it contains magnesium glycinate. We do not sell threonate. So we have an obvious reason to like glycinate, and you should weigh our view accordingly.

Each CALM+COLLECTED mint contains 120mg magnesium glycinate, 200mg L-theanine, 200mg lemon balm, 100mg holy basil and 20mcg vitamin D. It dissolves under the tongue, is caffeine-free and non-drowsy, and most people feel it in about 15 minutes. We chose glycinate because it is gentle and pairs naturally with L-theanine for calm you can take to work. The logic behind that pairing is in our magnesium glycinate and L-theanine evening reset.

What it is not: a full magnesium supplement. The glycinate is a supporting amount inside a calm blend, not a complete daily dose. If your intake is low, food comes first (pumpkin seeds carry about 156mg per ounce, per NIH ODS). And if memory is your specific goal, threonate is the form with that research.

Key Takeaways

• Threonate is about 7% magnesium by weight. Glycinate is about 14%, so it delivers roughly twice the mineral per gram.
• Threonate has the brain-specific research: strong in rats, small and early in humans.
• Glycinate has a human sleep trial showing a small benefit, plus a long record of being easy on the stomach.
• For anxiety, the evidence is for magnesium in general and is still low quality. No form has won a head-to-head.
• Keep supplemental magnesium at or under 350mg a day, and check with your doctor if you have kidney disease.

Explore the Series

• Magnesium for Brain Fog: What It Can and Cannot Do
• Magnesium Glycinate Benefits for Stress and Sleep
• Magnesium for Anxiety
• The Magnesium Glycinate and L-Theanine Evening Reset
• Cortisol and Sleep
• Racing Thoughts at Night

References

• Slutsky I, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010. PMID 20152124
• Liu G, et al. Efficacy and safety of MMFS-01, a synapse density enhancer, for treating cognitive impairment in older adults: a randomized, double-blind, placebo-controlled trial. J Alzheimers Dis. 2016. PMID 26519439
• Hausenblas HA, et al. Magnesium-L-threonate improves sleep quality and daytime functioning in adults with self-reported sleep problems: a randomized controlled trial. Sleep Med X. 2024. PMID 39252819
• Lopresti AL, Smith SJ. The effects of magnesium L-threonate (Magtein) on cognitive performance and sleep quality in adults: a randomised, double-blind, placebo-controlled trial. Front Nutr. 2025. PMID 41601871
• Schuster J, et al. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nat Sci Sleep. 2025. PMID 40918053
• Bannai M, et al. The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Front Neurol. 2012. PMID 22529837
• Boyle NB, et al. The effects of magnesium supplementation on subjective anxiety and stress: a systematic review. Nutrients. 2017. PMID 28445426
• Schuette SA, et al. Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection. JPEN J Parenter Enteral Nutr. 1994. PMID 7815675
• NIH Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals. ods.od.nih.gov

FAQ

Is Magnesium Threonate Better Than Glycinate?

Not across the board. Threonate has more brain-specific research, mostly in rats plus a few small human trials. Glycinate delivers about twice the elemental magnesium per gram, costs less and has its own sleep trial. Pick by goal: memory points to threonate, sleep and calm point to glycinate.

Can You Take Magnesium Threonate and Glycinate Together?

Yes, many people do. Just add up the elemental magnesium from both labels and keep the supplemental total at or under 350mg a day, the adult upper limit set for magnesium from supplements. If you have kidney disease or take prescription medication, check with your doctor first.

Which Magnesium Is Best for Sleep?

Both forms have small trials showing sleep benefits, and neither has been tested against the other. Glycinate is the common first choice because it is gentle, affordable and comes with glycine. Take it in the evening and give it a few weeks.

Which Magnesium Is Best for Anxiety?

The anxiety research is on magnesium in general, not one form, and reviews rate it as low quality but promising for people prone to anxiety. Glycinate is the practical pick for most people. If anxiety is affecting your daily life, talk to a doctor or therapist.

How Much Elemental Magnesium Is in Magnesium Threonate?

About 7% by weight. In published trials, 1 gram of magnesium L-threonate supplied about 75mg of elemental magnesium, and 2 grams supplied about 145mg. Glycinate is roughly 14% magnesium, so you get about twice as much per gram.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. If you have kidney disease, take prescription medication, or are pregnant or breastfeeding, check with your doctor before taking magnesium supplements.