Question & Context

I sleep badly – what really helps?

In brief

The measures that work best cost nothing: fixed wake-up times, caffeine only in the early part of the day, a dark, cool bedroom and no lying awake in bed for hours. For a real, persistent sleep disorder, cognitive behavioral therapy for insomnia is the first choice, ahead of any sleeping pill. Supplements such as magnesium, L-theanine or glycine show small positive effects, mainly on the subjective experience of sleep. Melatonin helps mainly with a shifted rhythm and jet lag; in classic insomnia, the effect is small. If you snore loudly and nod off during the day, you should have sleep apnea ruled out.

What matters first

A fixed wake-up time

The internal clock is most reliably set through the morning: get up at the same time every day, even after a bad night and on weekends, and get into daylight as soon as possible. Your bedtime then follows from your tiredness. As a guideline, the American sleep medicine societies recommend that adults regularly get 7 or more hours of sleep.

Stop caffeine early

Caffeine is one of the best-documented disruptors. A meta-analysis of 24 studies found on average 45 minutes less total sleep, 9 minutes longer to fall asleep and 12 minutes more time awake during the night. The authors advise drinking coffee at least 8.8 hours before bedtime, and high-dose pre-workout products at least 13.2 hours before.

The bed only for sleeping

If you lie awake for a long time, you link the bed with brooding. A core element of behavioral therapy is therefore stimulus control: go to bed only when you are tired, and get up if you cannot fall asleep. Phone, shows and work stay out.

Dark, cool, quiet

Light in the evening dampens the body's own melatonin release; this has been measured repeatedly in the sleep lab. A warm room costs deep sleep. Blackout, dimmed light in the evening and a rather cool bedroom are simple adjustments.

When you should have this checked by a doctor

You should have sleep problems checked by a doctor if they last for weeks and noticeably limit you during the day, and above all if you have these warning signs: loud snoring with observed pauses in breathing, nodding off in quiet situations or at the wheel, morning headaches, an unpleasant urge to move your legs in the evening, shortness of breath or a racing heart at night, and sleep problems together with persistent low mood or anxiety. Such complaints can be caused by sleep apnea, restless legs syndrome, a thyroid disorder or depression – all of which are treatable. Medications can also disturb sleep. The first point of contact is your family doctor, who can refer you to a sleep lab if needed.

Why behavioral therapy comes before any remedy

Cognitive behavioral therapy for insomnia, CBT-I for short, combines fixed sleep windows, stimulus control, relaxation and dealing with circling thoughts. The guideline of the American College of Physicians recommends it as the first treatment for all adults with chronic insomnia, as a strong recommendation. Sleeping pills only come into question if therapy alone is not enough.

Sleep hygiene tips alone help, but less: a meta-analysis of 42 randomized trials with 4,245 adults found an improvement for sleep hygiene as the sole measure, but it was inferior to full behavioral therapy. The good news: CBT-I is available as individual or group therapy and in digital form, so access has become easier.

What supplements can contribute

Magnesium is the most popular sleep supplement. In a double-blind trial in 155 adults with poor sleep, the insomnia index fell by 3.9 points over 4 weeks with 250 milligrams of magnesium as bisglycinate, and by 2.3 points on placebo. That is a small advantage on a questionnaire; a review of 12 studies rates the overall evidence as low to very low.

L-theanine has been studied more broadly: a meta-analysis of 19 papers with 897 participants found small but consistent improvements in time to fall asleep, daytime sleepiness and sleep quality, all measured subjectively. Glycine has three small studies, one of which showed faster sleep onset in the sleep lab. Both were well tolerated in the studies and are worth a try, but they do not replace the basics.

Melatonin is a special case. A meta-analysis of 19 placebo-controlled trials with 1,683 participants found a 7.06-minute shorter time to fall asleep. The effect was markedly stronger with a shifted sleep rhythm than in classic insomnia. The German Federal Institute for Risk Assessment considers that no safe maximum amount can be derived for food supplements and advises against them for children, pregnant and breastfeeding women and people with epilepsy or autoimmune diseases, among others. If you use melatonin, do so after consulting a doctor.

What the database says

Sorted by strength of evidence. The BK-Score rates the state of knowledge, not the substance.

CPAP for sleep apnea Evidence 9/10 · Well supported, heavily overhypedWhen pauses in breathing chop up sleep, the breathing mask eliminates them almost completely and markedly improves daytime sleepiness and quality of life. In the largest trial, however, it did not prevent heart attacks and strokes.
No caffeine after 2 p.m. Evidence 8/10 · Well supportedThe half-life of caffeine is a few hours on average and varies widely between individuals. The early-afternoon cutoff is derived from this and is a good starting point for most people.
Sleep & sleep hygiene Evidence 7/10 · Supported, with caveatsThe overview of sleep duration, regularity and sleep hygiene. Cognitive behavioral therapy is the best-supported method here, for insomnia, not for extending life.
Consistent sleep schedule Evidence 7/10 · Supported, with caveatsLarge cohorts show that regular sleep times are more closely linked to health than duration alone. This is not proven to be causal, but the advice costs nothing.
Complete darkness in the bedroom Evidence 7/10 · Supported, with caveatsLight in the evening dampens melatonin, measured with normal room light. Darkening the room is simple and well founded; the standby light is a much smaller factor.
Magnesium Evidence 7/10 · Supported, with caveatsIn a placebo-controlled trial in people with poor sleep, magnesium improved the insomnia questionnaire somewhat more than placebo. Nothing was measured objectively; the effect is small.
L-theanine Evidence 7/10 · Supported, with caveatsThe amino acid from tea shows consistent, small effects on perceived sleep quality and daytime sleepiness across many small studies. It does not make you tired, but rather calmer.
Melatonin Evidence 7/10 · Supported, with caveatsAccording to a meta-analysis, it shortens the time to fall asleep by a few minutes, more clearly with a shifted sleep rhythm and jet lag. The German Federal Institute for Risk Assessment advises certain groups against food supplements containing melatonin.
Bedroom at 16–18 °C Evidence 6/10 · Supported, with caveatsBody temperature has to drop for you to fall asleep; a room that is too warm costs deep sleep. The often-cited ideal temperature is a rule of thumb, not a measured optimal zone.
Glycine Evidence 5/10 · Thin human evidenceThree small human studies consistently report a benefit on at least one sleep endpoint, including shorter time to fall asleep in the sleep lab. Larger studies are lacking, so the effect has not been refuted, but it has never been tested thoroughly.

Frequently asked questions

How many hours of sleep do I need?

For adults, the American sleep medicine societies recommend 7 or more hours per night on a regular basis. Individual needs vary; a good indicator is whether you are alert and able to perform during the day without caffeine. Regularity is almost as important as duration.

Does magnesium help you fall asleep?

In a placebo-controlled trial, magnesium improved subjective sleep somewhat more than placebo. The effect was small and was measured only by questionnaire. As a well-tolerated thing to try, it is reasonable; as a solution for a real sleep disorder, it is not enough.

Does melatonin make sense for sleep problems?

In classic insomnia, melatonin shortens the time to fall asleep by only a few minutes. In jet lag and a shifted sleep rhythm, the effect is clearer. The German Federal Institute for Risk Assessment sees health risks in food supplements containing melatonin, so taking it should be discussed with a doctor.

What is cognitive behavioral therapy for sleep?

A structured program of fixed sleep windows, rules for the bed, relaxation and dealing with worries about sleep. It is considered the first choice for chronic insomnia, ahead of medication. It is offered in doctors' practices, sleep centers and as a digital program.

Why do I keep waking up at night?

Short waking phases are normal and are usually forgotten. They become more frequent and longer with late caffeine, alcohol in the evening, stress, a room that is too warm or the urge to urinate. If snoring, pauses in breathing or severe daytime sleepiness come on top of this, have sleep apnea checked.

Are sleep trackers any use?

They detect sleep and wakefulness fairly well, but the individual sleep stages unreliably. For trends such as sleep duration and regularity, they are useful. If you let a bad sleep score put you under pressure, you tend to sleep worse.