Magnesium Glycinate vs. Other Forms: A Sleep Showdown

Published February 2025 · 8 min read

Not all magnesium is created equal. For sleep, glycinate wins—and it's not close. Here's why the form matters more than the dose, and what to avoid.

The Form Comparison

Form	Absorption	Sleep Benefit	Notes
Glycinate	Excellent	⭐⭐⭐⭐⭐	Includes glycine (dual benefit)
Threonate	Good	⭐⭐⭐⭐	Crosses BBB well, expensive
Citrate	Good	⭐⭐⭐	May cause loose stools
Taurate	Good	⭐⭐⭐	Better for heart health
Oxide	Poor (4%)	⭐	Essentially a laxative

Why Glycinate Wins for Sleep

The Double Benefit

Magnesium glycinate combines magnesium with glycine—an amino acid that's also beneficial for sleep:

Magnesium: GABA cofactor, muscle relaxation, stress response

Glycine: Lowers core body temperature, supports blood sugar overnight, calming neurotransmitter

You get two sleep-supporting compounds in one supplement.

Glycinate is also highly absorbable (unlike oxide) and doesn't cause digestive issues (unlike citrate at higher doses).

The Deficiency Problem

An estimated 50%+ of Americans have suboptimal magnesium intake. Modern diets (processed foods, depleted soils) combined with stress (which burns magnesium) create widespread functional deficiency.

Signs you might be deficient: muscle cramps, restless legs, difficulty relaxing, poor stress tolerance, trouble sleeping. If you have several of these, magnesium supplementation is worth trying.

Dosing for Sleep

Starting: 200mg elemental magnesium (as glycinate)

Typical: 300-400mg elemental magnesium

Timing: 30-60 minutes before bed

Note: Check labels for "elemental" magnesium—a 500mg glycinate capsule contains less than 500mg actual magnesium.

Best Products

NOW Magnesium Glycinate: Budget-friendly, good quality, GMP certified. Our top pick for value.

Thorne Magnesium Bisglycinate: NSF certified, higher purity standards. Worth the extra cost if quality is priority.

Avoid: Products that mix glycinate with oxide or citrate to pad the magnesium content.

Compare Magnesium Products

See how different magnesium products rank for sleep support.

→ View complete rankings

The Bottom Line

For sleep, magnesium glycinate is the clear winner. You get well-absorbed magnesium plus glycine's additional sleep benefits. Avoid oxide (poorly absorbed) and be cautious with citrate (digestive effects). Most people benefit from 300-400mg elemental magnesium at bedtime.