Sleep biohacks: which ones are actually backed by research?

What does it mean to biohack your sleep?

Changing the environment and habits around sleep with the same care people put into training. A lot is sold under the word: supplements, rings, mats, apps. Much of it has little behind it. This list does the opposite and sorts by what has actually been measured, with how many people each study included. It is what you build your lock in period on.

How much does evening light matter?

More than anything else on the list. Gooley and colleagues had 116 people aged 18 to 30 spend the eight hours before bed in either ordinary room light or dim light for five days (Journal of Clinical Endocrinology & Metabolism 2011). With room light, the period with melatonin in the body was about 90 minutes shorter. Room light during the sleep hours themselves suppressed melatonin by more than half.

Screens add to it. When twelve people read on a lit screen for four hours before bed for five evenings, melatonin was 55 percent lower than with a printed book, it started an hour and a half later, and they got twelve minutes less REM sleep per night (Chang et al., PNAS 2015). The blue band between 446 and 477 nm suppresses melatonin the most (Brainard et al. 2001).

When should you stop drinking coffee?

At least six hours before bed, and earlier is better. Drake and colleagues gave twelve healthy people 400 mg of caffeine zero, three or six hours before bedtime (Journal of Clinical Sleep Medicine 2013). Even at six hours, measured sleep fell by more than an hour. In their sleep diaries, participants did not notice. Caffeine costs you sleep you do not know you are losing.

Does alcohol help you fall asleep?

Yes, and that is the problem. A review of 20 studies in Alcoholism: Clinical & Experimental Research in 2013 found that alcohol makes you fall asleep faster and sleep more deeply in the first half of the night. The first REM period is delayed, REM sleep goes down across the night at moderate and high doses, and the second half of the night is more disrupted. What feels like a good night is a shorter night with a worse ending.

Do orange glasses work as a sleep biohack?

The evidence is mixed, and that should be said plainly. In a Japanese study, nine patients with delayed sleep phase wore orange glasses from 9 pm until bedtime for two weeks and fell asleep an average of 132 minutes earlier by movement tracking (Esaki et al. 2016). The study was small and had no control group. The 2023 Cochrane review rates the effect on sleep as uncertain. What the lens does is remove the band that suppresses melatonin: the orange filters 98 % of blue light and the red 99 % between 400–550 nm.

The red glasses tell my mind it's time to slow down. They help me relax, switch off, and wake up ready for the next day.

Customer review

In which order should you do it?

• A fixed wake-up time, seven days a week.
• Outdoor daylight in the morning, see Winter daylight in Sweden.
• Last coffee at least six hours before bed.
• No alcohol on weeknights.
• Dim the ceiling light two hours before bed and turn screen brightness down.
• Orange lens from sunset, red for the last hour. The lens does most on top of less light, not instead of it.
• The phone charges outside the bedroom.