Magnesium L-Threonate vs Glycinate: Which One Do You Need?

One is the brain form. One is the calm form. Here's what the trials show, and why the best answer is often both.

By the Gold Seal Nutrition Team
Updated October 12, 2026

✓ Checked against 6 human trials on PubMed

Threonate and glycinate do different jobs, which is why they're often combined.

Quick answer

Threonate is the brain form: deeper sleep and memory in human trials
Glycinate is the calm form: gentle on the stomach, helps you wind down
For sleep plus clear mornings, taking both covers the most ground

Side by side

	L-Threonate	Glycinate
Known for	Brain magnesium, sleep quality, memory	Calm, gentle absorption
Key human trial	2024: deeper and REM sleep in 21 days¹	2025: lower insomnia scores in 4 weeks³
Memory research	✓ ages 50 to 70²	✗
Studied dose	1,000 to 2,000 mg a day	About 250 mg magnesium a day
Stomach	Usually fine	Very gentle

Why not just one?

Threonate on its own gives a modest amount of magnesium (2,000 mg of threonate provides about 144 mg). Glycinate on its own doesn't target the brain. That's why Gold Seal Magnesium Complete, which we make, pairs the full 2,000 mg of threonate with 550 mg of bisglycinate, plus malate and taurate, for 298 mg of magnesium a day.

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2,000 mg magnesium L-threonate, the same dose used in the clinical memory studies
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Why the dose is the whole story

Most magnesium labels never tell you this: the research used a specific amount, and most products use much less. A capsule can list "magnesium L-threonate" and still contain a sprinkle.

Sleep study (2024)

1,000 mg

Memory studies (2016, 2022)

up to 2,000 mg

Magnesium Complete

2,000 mg every day

So you get the same amount used in the memory studies,² ⁵ which is double what the sleep study used.¹ Then the formula adds three more forms that each do a different job.

Talk to your doctor first if you: take heart rhythm, blood pressure or blood-thinning medicine, take antibiotics or osteoporosis drugs, have kidney disease, or are pregnant or nursing.

Frequently asked questions

Is magnesium L-threonate or glycinate better for sleep?

Both have sleep trials. Threonate improved deep and REM sleep scores in a 2024 trial; glycinate lowered insomnia scores in a 2025 trial. They work differently, so many people take both.

Can you take magnesium L-threonate and glycinate together?

Yes. They are often combined. Keep total magnesium from supplements within what your doctor recommends.

Which is better for memory?

Threonate. It is the form shown to raise magnesium in the brain, and trials in adults, including ages 50 to 70, found better memory and thinking scores.

How we researched this. This guide was written by the Gold Seal Nutrition Team. We used AI research tools to pull and read the randomized human trials on magnesium L-threonate, magnesium bisglycinate and magnesium in older adults that are indexed on PubMed. Then we checked every number against the original paper. Each claim links to its source below. We make Magnesium Complete, so we earn money when you buy it, and we tell you that up front.

Sources

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;8:100121. Source
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;49(4):971-990. Source
Schuster J, et al. Magnesium bisglycinate supplementation in healthy adults reporting poor sleep: a randomized, placebo-controlled trial. Nat Sci Sleep. 2025;17:2027-2040. Source
Abbasi B, et al. The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161-1169. Source
Zhang C, et al. Randomized, double-blind, placebo-controlled trial of a magnesium L-threonate-based formula on memory in healthy adults. Nutrients. 2022;14(24):5235. Source
Lopresti AL, Smith SJ. Randomised, double-blind, placebo-controlled trial of magnesium L-threonate on cognitive performance and sleep quality in adults. Front Nutr. 2026;12:1729164. (Adults aged 18 to 45, 2 g a day for 6 weeks.) Source
NIH Office of Dietary Supplements. Dietary Supplement Label Database: NOW Magnesium Caps 400 mg, Nature Made Magnesium Glycinate 200 mg, Doctor's Best High Absorption Magnesium, Pure Encapsulations Magnesium (Glycinate). Source