The Study
Home lighting, blue-light filtering, and their effects on melatonin suppression
This study didn’t test real people or their sleep. Instead, it measured the light from 52 different lamps and used math to guess how much each one might affect melatonin. It’s like predicting how wet you’d get in different rainstorms by just looking at the clouds — it’s an estimate, not a real measurement.
Analysis score
Maximum 44 for a cross-sectional study.
Where the score came from
Some lights at home, especially bright white ones, can trick your brain into thinking it's still daytime by blocking the sleep hormone melatonin. This makes it harder to fall asleep.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 543 / 100
Quality score
Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes, these differences matter because even small changes in melatonin can affect how fast you fall asleep and how well you sleep overall.
- 2Cool white LED and CFL lights block about 12% of melatonin.
- 3Warm white LEDs block 3-4%, and old-style bulbs block only 1.5%.
- 4Turning a tunable lamp from cool to warm reduces melatonin blocking from 10% to 0.1%.
- 5Brown-colored glasses can cut blocking to less than 0.3%.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Scientific Reports
Year
2026
Authors
Emiliano Terán, C. Yee-Rendon, Hugo J Sosa-Arámbula, A. K. De la Herrán-Arita, R. L. Woods
Related Content
Claims (6)
Cool white LED lights might mess with your sleep more than old-style light bulbs because they affect your body's internal clock more, even if they look just as bright. Old incandescent bulbs are gentler on your circadian rhythm at night.
Being around blue light at night, like from phones or screens, might keep your body from making the sleep hormone melatonin because it keeps stress hormone levels high, making it harder to fall and stay asleep.
Cool white light bulbs, like some LEDs and CFLs, might mess with your sleep more than warm yellowish ones because they can reduce a sleep hormone called melatonin more strongly.
Changing your LED light from cool white to warm white in the evening can cut down how much it messes with your sleep hormones by over 99%.
Wearing brown-tinted blue-light-blocking glasses like Swanwick or THL Sleep at night might help protect your sleep hormone way better than other blue-light glasses by blocking more of the light that messes with your body clock.
Incandescent light bulbs are the least likely to mess with your sleep at night because they give off less of the blueish light that tricks your brain into staying awake.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.