Sleep Labs

Consumer trackers are most accurate for tracking total sleep time and wake periods (85–90% agreement with lab polysomnography). Sleep stage accuracy is lower — light vs. deep sleep distinctions are roughly 65–75% accurate. The practical implication: use trackers for trends and patterns, not precise stage measurements. Consistency of the same tracker over time is more useful than absolute accuracy.

White noise contains equal energy at all frequencies — it sounds hissing and static-like. Pink noise has more energy at lower frequencies, producing a softer, more natural sound like rain or wind. Research shows pink noise improves slow-wave sleep quality more than white noise for most people, though individual preference matters. Most quality machines offer both; we recommend starting with pink.

Low-dose melatonin (0.5–1mg) taken 90 minutes before target sleep time is well-supported for circadian phase adjustment — particularly for jet lag and shift work. Higher doses (5–10mg) common in US supplements are not more effective and can cause next-day grogginess. We note supplement interactions in our sleep aid reviews but don't make supplement recommendations as they fall outside our product testing scope.

The research consensus and our user tracking point to 65–68°F (18–20°C) as optimal for most adults. Core body temperature naturally drops 1–2°F as part of sleep initiation, and a cool room accelerates this process. Users who cooled their room from 72°F+ to this range reported falling asleep faster without any other changes in our 30-day environmental testing.

Yes — particularly when worn 2+ hours before bedtime. Blue light suppresses melatonin production, and wearing amber-lens glasses (95%+ blue light blocking) in the evening accelerates melatonin onset. In our testing, users who wore blocking glasses from 8pm onward fell asleep an average of 19 minutes faster after 2 weeks. Clear-lens glasses marketed for sleep are largely ineffective — the amber tint is required.