Blue Light Reduction
Dim lights and avoid screens 2-3 hours before bed to protect melatonin production. Use warm/amber lighting and blue-light blocking glasses if screen use is unavoidable.
Dosage & Timing
Evidence Strength
4/5 — StrongStrong mechanistic evidence for melatonin suppression by blue light. Practical effect size varies by individual sensitivity and implementation.
Overview
Minimize exposure to bright artificial light, especially blue-wavelength light, in the 2-3 hours before bedtime. This prevents suppression of melatonin production and supports natural sleep onset.
How To Do It
Set a light curfew
2-3 hours before your target bedtime, begin dimming overhead lights.
Switch to warm lighting
Use lamps with warm/amber bulbs instead of overhead fluorescents or LEDs.
Reduce screen brightness
Enable night mode on all devices. Consider blue-light blocking glasses.
Avoid bright bathrooms
Use a dim nightlight for bathroom visits instead of bright overhead lights.
The Evidence
Each claim is linked to its source study. Confidence reflects the study design — systematic reviews and RCTs rank highest.
Evening use of light-emitting eReaders negatively affects sleep, circadian timing, and next-morning alertness↗
Evening light-emitting screen exposure suppressed melatonin and delayed circadian timing.
Primary Literature
Who Popularized This
Interactions & Warnings
Interactions
- •Works synergistically with morning sunlight exposure
Measurable Outcomes
Equipment Needed
- • Blue light blocking glasses (optional)
- • Warm-tone light bulbs (optional)
Related Protocols
Morning Sunlight Exposure
View bright light within 60 minutes of waking to set your circadian clock. This triggers a cortisol pulse and starts a timer for melatonin release 14-16 hours later.
Consistent Wake Time
Set one wake time and stick to it 7 days/week. This anchors your entire circadian system more reliably than any other single habit.
Tart Cherry Juice for Sleep
Tart cherry juice is a natural source of melatonin and tryptophan-sparing compounds. Clinical trials show it increases sleep time by ~84 minutes in adults with insomnia.
Consistent Sleep-Wake Schedule
Keep wake time and bedtime within about 30-60 minutes day to day. Regular timing strengthens circadian cues and reduces the physiological cost of social jet lag.