Magnesium is not one supplement - form determines tolerability and likely use case. Glycinate and threonate are often compared for sleep, stress, and cognitive support. Here's how to choose based on goals and side-effect profile.[5]
What changes by form
Different magnesium salts have different GI tolerance and absorption behavior. The form you choose can matter as much as dose.
Glycinate is often favored for sleep-related goals due to better tolerability in many users.
When threonate may be preferred
Threonate is commonly selected when cognitive support is the primary goal, though evidence remains more limited compared with broader magnesium literature.
Cost is usually higher, so goal-specific use makes more sense than routine defaulting.
Practical dosing and monitoring
Start low, assess tolerance, then titrate. Overshooting dose often creates GI side effects that reduce adherence.
If sleep or stress benefit is unclear after a consistent trial, re-evaluate form, timing, and broader sleep architecture drivers.