Best Magnesium for Sleep: Glycinate vs. Threonate

If you’ve searched “which magnesium is best for sleep,” you’ve seen a dozen forms on the shelf. Two come up most often for winding down at night: magnesium glycinate (also called bisglycinate) and magnesium threonate.

Magnesium glycinate

Magnesium bound to glycine, an amino acid. It’s known for being gentle on the stomach, which matters because other forms, like citrate and oxide, can loosen stools. It’s the most common pick for evening use, and it’s usually the better value.

Magnesium threonate

Magnesium bound to threonic acid. It’s marketed for the brain and is often sold under the branded ingredient Magtein. It contains less elemental magnesium per capsule and costs more, so you’re paying for the form, not the amount.

Which should you choose?

• On a budget, or new to magnesium: start with glycinate.
• Curious about threonate: try it on its own for a week or two, so you can tell whether it does anything for you.
• Either way: add one supplement at a time and keep everything else the same. That’s the only way to know what’s working.

What to check on the label

• Elemental magnesium per serving. This is different from the compound weight, and it’s what actually counts.
• Added ingredients. Some sleep blends add B6, and B6 adds up across supplements.
• A certification seal. NSF Certified for Sport, NSF/ANSI 173, or USP Verified means an independent program has tested the product.

Brands with third-party certification

We list magnesium from brands certified by NSF or USP, including Momentous, Thorne, BiOptimizers, Nature Made, and Double Wood. Check the Where to Buy section for current listings.

Before you take it

High doses can cause loose stools. Talk to your doctor if you have kidney problems or take prescription medication.

This article is for education, not medical advice. These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease. We may earn a commission from links on this site.