Benefits of magnesium glycinate versus magnesium threonate

Direct answer: Magnesium glycinate is mainly valued for sleep support and gentler stomach effects; magnesium threonate may support sleep as well as cognition, though its cognitive evidence is still limited. 1

• Magnesium glycinate: Glycine itself is associated with sleep, and Huberman describes glycinate and threonate as potentially helping people fall asleep faster and sleep more deeply. The cited discussion does not establish that glycinate reliably avoids morning grogginess. 2 3
• Magnesium threonate: It may cross the blood-brain barrier more readily and could support cognition or neuroprotection. However, much of the supporting cognitive evidence is from animal studies, with limited human research. 4 5
• Sleep and choice: Both forms are described as potentially beneficial for sleep. The better fit depends on what you’re seeking—sleep support or possible cognitive effects—and individual response; some people experience gastrointestinal discomfort with magnesium. 6 7