Evidence: Weak

Small, short or mixed studies. Might help; might not. How we rate evidence.

Bedding materialsCotton, linen, wool, silk, down and synthetics compared. Few good studies exist; choose by whether you sleep hot or cold, and don't expect mite-proof covers to fix allergies.
- Evidence: Weak
- Low effort
- Medium cost
- Works: tonight
Breathing techniquesSlow breathing at about 6 breaths a minute reliably raises HRV while you do it. Evidence that it improves sleep is small but promising; 4-7-8 and box breathing have even less.
- Evidence: Weak
- Low effort
- Free
- Works: tonight
Duvet weight and layeringMatch your duvet's warmth (tog) to the season, and use layers so you can adjust through the night. Weighted blankets have some evidence, but mainly in people with psychiatric conditions.
- Evidence: Weak
- Low effort
- Medium cost
- Works: tonight
Evening mealsEat dinner 3–4 hours before bed if you can (at least 2–3), keep it moderate in size, and go easy on spice and fat if you get reflux. Most studies on food and sleep are small.
- Evidence: Weak
- Low effort
- Free
- Works: tonight
GlycineThree grams of glycine before bed improved how people felt about their sleep in a few tiny Japanese trials, most run by a glycine maker. Promising, but far from proven.
- Evidence: Weak
- Low effort
- Low cost
- Works: 1–3 nights in trials
HumidityAim for 40–60% relative humidity in the bedroom. Hot and humid is the combination that clearly hurts sleep; very dry air mostly affects your eyes, nose and throat.
- Evidence: Weak
- Low effort
- Low cost
- Works: tonight
L-theanineL-theanine, an amino acid from tea, may slightly improve how well you feel you sleep. The effect is small, mostly self-reported, and many studies mixed it with other ingredients.
- Evidence: Weak
- Low effort
- Low cost
- Works: 2–8 weeks in trials
Late mealsFinish your last big meal at least 2 to 3 hours before bed, especially if you get heartburn. The evidence for sleep itself is thin and mixed.
- Evidence: Weak
- Medium effort
- Free
- Works: tonight
MagnesiumMagnesium might shorten the time it takes older adults to fall asleep a little, but the trials are few, small and low quality. Stay at or under 350 mg a day from supplements.
- Evidence: Weak
- Low effort
- Low cost
- Works: 2–8 weeks in trials
Mattress firmnessMedium-firm is the best-supported choice, especially if you have low back pain. The evidence is real but low quality, so your own comfort over a few weeks matters most.
- Evidence: Weak
- Medium effort
- High cost
- Works: about 4 weeks
Mouth tapingTaping your mouth shut at night is a social media trend with weak evidence and real risks. It doesn't treat sleep apnea.
- Evidence: Weak
- Low effort
- Low cost
- Works: unknown
Nasal stripsExternal nasal strips open the front of your nose a little. They may help snoring from a stuffy nose, but they don't treat sleep apnea.
- Evidence: Weak
- Low effort
- Low cost
- Works: tonight
Orthosomnia, or worse sleep from score anxietyWorrying about your sleep score can make you feel worse and sleep worse. How to tell if it's happening to you, and what to do.
- Evidence: Weak
- Low effort
- Free
- Works: 1–2 weeks
PillowsPick pillow height to keep your neck level for the way you sleep. The research is thin; latex pillows have the most support for neck pain, and feather pillows the least.
- Evidence: Weak
- Low effort
- Low cost
- Works: 1–2 weeks
SaunaMany regular sauna users say it helps them sleep, but no good trial has tested it. If you enjoy it, finish an hour or two before bed, drink water and skip the alcohol.
- Evidence: Weak
- Medium effort
- Medium cost
- Works: tonight
Sharing a bedSharing a bed with a partner or pet has pluses and minuses, and the research is thin. Separate duvets, earplugs and a dog off the bed are easy fixes to try.
- Evidence: Weak
- Low effort
- Low cost
- Works: tonight
Tart cherryTart cherry juice added sleep time in a few tiny trials, but the evidence is weak, several trials were industry-funded, and the juice is high in sugar.
- Evidence: Weak
- Low effort
- Low cost
- Works: 1–2 weeks in trials
Wind-down routineGive yourself 30–60 minutes of dim, quiet, low-effort time before bed. A few parts are tested; most of it is sensible rather than proven.
- Evidence: Weak
- Low effort
- Free
- Works: 1–2 weeks