sleep · Outcome
Total time asleep per night. Most adults need 7-9 hours; chronic shortfall under 6 raises mortality, glucose dysregulation, and cognitive risk.
How to measure: Wearable total sleep time (Oura, Whoop, Apple Watch). Self-report works as a backup but consistently overestimates by 20-40 min vs. actigraphy.
Three levers, one stack. Each works through a different mechanism. They compound.
Improves sleep
200-400 mg elemental Mg · 60-90 min before bed
Evidence
Effect size
Research
12 papers
directional · 12 studies · no reliable magnitude
Why: Best balance of safety and effect for duration. Glycinate avoids the laxative effect of oxide. Don't expect 90 extra minutes; expect 15-30 plus better wake-time energy.
See the Magnesium Glycinate pageImproves sleep
Same bed and wake times daily (within 30 min) · All week, including weekends
Evidence
Effect size
Research
58 papers
directional · 58 studies · no reliable magnitude
Evidence pending
240-480 ml · 60-90 min before bed
Evidence
Effect size
Research
None
Everything we found, ranked by how strongly we recommend it. Tap any to see the studies.
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Every pick has two signals. They answer different questions and we never bundle them into one number.
Effect size
How big is the change on sleep duration, in the units that matter for this outcome.
Confidence
How sure are we the effect is real for sleep duration, given the studies we have.
For every pick, the “papers” number is how many studies we've cataloged that test this entity for sleep duration. “Favorable” means the study reported the direction you want.
The tier badge (S, A, B…) on the entity itself is its overall research confidence across all outcomes. It's the same letter wherever you see this entity on the site, not specific to sleep duration.
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Why: Most people can't reliably sleep 8 hours if their bedtime drifts by 2 hours night to night. Anchor wake time first; the bedtime falls into place.
Why: Sole food with direct RCT evidence on sleep duration in the research we track. Effects strongest in older adults; younger people see smaller bumps.