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SleepUncovered

Sleep hygiene — what actually works

Updated16 May 2026Read time7 minReviewed bySleepUncovered editorial

Short answer

Strong evidence

Most “sleep hygiene” advice has weak evidence behind it. A small number of interventions — morning light, consistent timing, a cool bedroom, alcohol restriction, and CBT-I for chronic cases — have strong evidence. The rest is mostly folklore.

Key points

  • Sleep hygiene alone rarely fixes chronic insomnia. It's necessary but not sufficient.
  • The strongest interventions: morning bright light, fixed wake time, cool room (16–19°C), no alcohol within 3h of bed, screen restraint, and CBT-I if chronic.
  • Weak or null evidence: lavender, chamomile tea, bath salts, sleep teas, weighted blankets (modest effect), white noise (mixed).
  • Sleep hygiene works as prevention and maintenance. Once insomnia is established, behavioural therapy is the larger lever.
  • Most sleep supplements have less evidence than the highest-evidence hygiene interventions.

The ranking

Strong evidence — do these first

  • Consistent wake time (every day). The single biggest lever for circadian stability. Bigger effect than consistent bedtime.
  • Bright morning light exposure (10–30 min). Anchors the circadian rhythm, supports evening sleepiness.
  • Cool bedroom (16–19°C / 60–67°F). Allows the 1°C core body temperature drop needed for sleep onset.
  • Alcohol restriction (none within 3h of bed). Removes the single most common cause of fragmented second-half-of-night sleep.
  • Caffeine cut-off (8–10h before bed). Earlier than commonly recommended; depends on metabolism.
  • Dark, quiet sleep environment. Blackout curtains, eye mask, or removing phone displays. Light fragments sleep.
  • CBT-I for chronic insomnia. First-line per all major guidelines.

Moderate evidence

  • Wind-down routine (30–60 min before bed). Helps consistency, lowers arousal — particularly useful for those with sleep anxiety.
  • Exercise (regular, any time). Improves overall sleep quality. The “don't exercise late” rule is overstated for most people.
  • Pre-bed warm shower (60–90 min before). Speeds sleep onset by ~10 min via the counter-cooling response.
  • Bedroom as a single-purpose space. Component of stimulus control. Big lever in chronic insomnia, smaller in general use.
  • Short morning naps (under 20 min, before 3pm). Beneficial for most. Longer or later naps reduce night sleep quality.

Limited evidence — small effects at best

  • Lavender oil aromatherapy. Modest anxiolytic effect. Sleep impact is small.
  • Weighted blankets. Subjective improvement in sleep quality; effect on objective sleep parameters is small.
  • Sleep teas (chamomile, valerian, etc.). Mild effects, dose typically too low to matter.
  • White noise machines. Mixed evidence. Some people benefit; others find arousal increases.
  • Blue-light filtering glasses. Reduce melatonin suppression in lab studies; subjective sleep impact is small.
  • Avoiding all screens 2h before bed. Content arousal matters more than screen wavelength. Switching from stimulating content to calming content matters more than eliminating screens.

Weak or no evidence

  • Sleeping in absolute silence. Some background noise is normal and not harmful.
  • Bedroom feng shui / bed orientation. No credible evidence.
  • Counting sheep. Specifically tested in studies — worse than imagining relaxing scenes or doing nothing.
  • Bath salts marketed for sleep. Hot baths help via mechanism above. The salt is irrelevant.
  • Mattress upgrades for general sleep. Subjective improvement common but objective sleep gains are small unless the previous mattress was actively painful.

Putting this together

If you have no current sleep complaint, the high-evidence interventions are preventive maintenance: consistent timing, morning light, cool room. They're free and have no downside.

If you have chronic insomnia, the high-evidence interventions are necessary baseline but not sufficient. CBT-I is the treatment with the strongest evidence — see CBT-I explained.

If your sleep is fine except for one specific issue (waking early, can't fall asleep, etc.), look at the relevant problem page rather than working through a general hygiene list.

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