How to Sleep Better: What the Evidence Says

The way to sleep better with the strongest evidence is a course of therapy that NICE makes first line: cognitive behavioural therapy for insomnia (CBT-I), which across 20 trials of 1,162 adults brought sleep onset forward by 19 minutes and cut time awake in the night by 26 minutes, with the gains holding after treatment ended. Next come the habits the NHS lists and a fixed wake time. Among ingredients, the trials measure their gains in minutes: melatonin, a prescription-only medicine in the UK, about 7 minutes sooner to sleep across 19 trials; magnesium about 17 minutes in three small trials of older adults; the others smaller, or measured by questionnaire.^1,2,3,4 This page is the Wellgard sleep guide: it separates a bad patch from insomnia from a sign that needs a GP, in NHS and NICE wording, grades the common ingredients in the same units, and routes every sleep question to the page that answers it.

Is this a bad patch, insomnia, or something to get checked?

The NHS definition: "Insomnia means you regularly have problems sleeping. It usually gets better by changing your sleeping habits." You have it if you regularly "find it hard to go to sleep", "wake up several times during the night", "wake up early and cannot go back to sleep" or "still feel tired after waking up". Under 3 months it is short-term; "insomnia that lasts 3 months or longer is called long-term insomnia".⁵ NICE's Clinical Knowledge Summary (CKS) adds the test that separates a bad patch from a disorder: insomnia "results in impaired daytime functioning", and "sleep disturbance in the absence of daytime impairment is not considered to be insomnia disorder". Short-term insomnia "is common and can occur in association with stressful events or changes in sleeping patterns".⁶

• A bad patch is a run of poor nights around a stressor, with days you still get through. It usually has an ordinary cause: Why Do I Wake Up at 3am? Causes and Getting Back to Sleep and Tired but Wired: Why You Are Exhausted but Cannot Sleep work through the checklists.
• Insomnia is the regular pattern with a daytime cost. The NHS says to see a GP if "changing your sleeping habits has not helped your insomnia", "you've had trouble sleeping for months" or "your insomnia is affecting your daily life in a way that makes it hard for you to cope".⁵
• A red flag is a sign the NHS lists separately: "snoring or interrupted breathing while sleeping (sleep apnoea)", "suddenly falling asleep anywhere (narcolepsy)", "restless legs syndrome", "nightmares or night terrors", or insomnia with "stress, anxiety or depression".⁵ CKS asks that "other sleep disorders (such as obstructive sleep apnoea, restless legs syndrome, and parasomnias) should be considered".⁶ Each is a GP matter on its own; chest pain or severe breathlessness on waking is a 999 call. When to See a GP About Sleep: Red Flags, 111 and 999 quotes every threshold.

What does the NHS say to try first?

The NHS list. Do: "only go to bed when you're sleepy"; "wake up and get out of bed at the same time every day"; "relax at least 1 hour before bed"; "make sure your bedroom is dark and quiet"; "exercise regularly during the day". Don't: "smoke or drink alcohol, tea or coffee at least 6 hours before going to bed"; "eat a big meal late at night"; "exercise at least 4 hours before bed"; use devices right before bed, "because the blue light makes you more awake"; nap during the day; or "sleep in after a bad night's sleep".⁵ Each item is linked to sleep in population and laboratory studies, though its direct effect on its own "remains largely untested in the general population"; CKS asks that sleep hygiene "be considered in all people with insomnia" and names CBT-I as the treatment when the problem persists.^6,7 A Bedtime Routine for Adults That Works, Step by Step builds the hour before bed; How to Switch Off Your Mind at Night: Racing Thoughts and Overthinking handles the racing mind; Foods That Help You Sleep: What to Eat Before Bed, in UK Portions and What to Drink Before Bed: Sleep Drinks Ranked by Evidence cover the late meal and the bedtime drink; Viral Sleep Rules and Tricks: What the Evidence Says tests the 3-3-3 rule and the military method.

What is the best-evidenced treatment for insomnia?

CKS: "Cognitive behavioural therapy for insomnia (CBTi) is recommended for the treatment of both short- and chronic insomnia in adults of all ages — unlike medication, benefits associated with CBTi persist after completion of treatment." For chronic insomnia it "should be offered as the first-line treatment in adults of any age", and "hypnotic medication should be avoided if possible due to the potential for significant adverse effects".⁶ The NHS: you may be offered CBT "face-to-face with a therapist, or through an online self-help programme", and "GPs now rarely prescribe sleeping pills to treat insomnia".⁵ In 20 randomised trials of 1,162 adults with chronic insomnia, CBT-I shortened sleep onset by 19.03 minutes, cut wake after sleep onset by 26.00 minutes and raised sleep efficiency by 9.91 percentage points; total sleep time rose by 7.61 minutes, which did not reach statistical significance; no adverse outcomes were reported and the changes "seemed to be sustained".¹ Melatonin, the sleep medicine many readers expect to buy, "is available on prescription only" and is "mainly used to treat short-term sleep problems in people aged 55 and over".³ Why Is Melatonin Prescription-Only in the UK? What It Does explains the classification.

Which everyday habits have the largest measured effect?

A fixed wake time. In 60,977 UK Biobank participants wearing wrist monitors, higher sleep regularity was associated with a 20% to 48% lower risk of all-cause mortality across the top four regularity quintiles compared with the least regular, and regularity predicted mortality more strongly than sleep duration. It is observational, and the strongest evidence any single habit has.⁸ The night the whole country breaks the rule: The Clocks Go Back on 25 October: What It Does to Your Sleep.

Caffeine timing. Across 24 studies, caffeine cut total sleep time by 45 minutes and sleep efficiency by 7%, and added 9 minutes to falling asleep and 12 minutes to time awake in the night; to avoid losing total sleep, a 107 mg coffee should be taken "at least 8.8 h prior to bedtime".⁹ The NHS's 6-hour rule is the floor.⁵ Caffeine and Sleep: When to Stop and How Long It Lasts has the half-life arithmetic.

Alcohol. The review of the laboratory studies in healthy volunteers: "At all dosages, alcohol causes a reduction in sleep onset latency, a more consolidated first half sleep and an increase in sleep disruption in the second half of sleep".¹⁰ That is why a nightcap so often ends at 3am; see "Could it be alcohol, or eating late?" on the 3am page and "Does a nightcap help you sleep?" on the drinks page.

Which sleep supplements have evidence, and how large is it?

Sleep trials measure minutes to fall asleep, minutes awake in the night, total sleep and questionnaire scores. The table describes the size of the literature, not a verdict on the ingredient.

The ingredient-by-ingredient grading, including "What is the strongest natural sleep aid?", is Which Sleep Supplements Have Evidence Behind Them? A UK Guide. Magnesium has three more pages: Which Magnesium Is Best? Glycinate, Citrate, Oxide and Malate Compared, What Is Magnesium Glycinate? Dose, Side Effects, Who Should Avoid and Is It OK to Take Magnesium Every Day? Dose, Signs of Too Much. Tart cherry's wider evidence is in What Is Tart Cherry Good For? The Montmorency Evidence by Outcome. Sleep Powders, Gummies, Capsules, Teas and Drops Compared shows what each format carries per serving.

What may a UK label say about sleep?

"Only authorised claims in the Great Britain NHC register may be used in Great Britain."²⁶ The register carries authorised wording for magnesium ("contributes to a reduction of tiredness and fatigue", "normal functioning of the nervous system", "normal psychological function", "normal muscle function") and for pantothenic acid ("the reduction of tiredness and fatigue"), each for a product supplying at least 15% of the reference intake.²⁶ Glycine, L-theanine, L-tryptophan, chamomile, lemon balm, tart cherry and ashwagandha have no authorised claim, so a UK label states their amounts and nothing about sleep. Melatonin cannot be a supplement ingredient here, because it is a medicine; "melatonin-free" on a pack describes the formula.³ Two label lines matter: L-tryptophan is permitted in a food supplement only if "the recommended daily dose for that food supplement does not exceed 220 mg", while the pooled trials found their effect at 1 g or more^14,15; and "green tea leaf extract providing L-theanine" states the weight of the extract, not of the theanine. How to Choose a Melatonin-Free Sleep Supplement in the UK goes line by line, including why a registered herbal remedy may say "to aid sleep" when a supplement cannot.

Who should ask a pharmacist or GP before taking anything for sleep?

The NHS line is "check with your doctor before taking anything for your sleep problems", and on its melatonin page: "do not take any herbal remedies which may affect sleep at the same time. This may make you very drowsy."^3,5 The groups that should ask first: anyone taking an antidepressant or another medicine that acts on serotonin (Can You Take Sleep Supplements With Antidepressants?); anyone on a sleeping tablet, sedative or strong painkiller; anyone pregnant or breastfeeding; anyone with thyroid or liver disease, for whom Who Should Not Take Ashwagandha? Liver, Thyroid and Medicines and Is Ashwagandha Safe to Take Daily? How Long, When and How to Stop set out the cautions; anyone with kidney disease, for whom the magnesium every-day page covers dose and the signs of too much; and anyone on antibiotics or bisphosphonates, which need spacing from magnesium ("Medicines to separate from magnesium glycinate" on the glycinate page). Tart Cherry Juice Warnings: Who Should Not Take It covers the juice. If the problem began with a new medicine, the NHS notes that "many medicines can also cause insomnia"; raise it with the prescriber.⁵ Does Mounjaro Cause Insomnia or Vivid Dreams? covers the one medicine the blog follows in depth.

Does the answer change at perimenopause or with a deficiency?

The NHS lists menopause, an overactive thyroid and restless legs syndrome among the conditions that can cause insomnia.⁵ Perimenopausal waking is the largest single pattern in readers' questions: Perimenopause Sleep Problems: What Actually Helps covers it, and Which Menopause Supplements Have Evidence? An Honest Review grades the supplements in the same units. "What vitamin am I lacking?" is the other recurring question: the vitamin D result in the table comes from a review of the deficiency link, and Which Vitamin Deficiency Affects Sleep? What to Test First explains which deficiencies are tested for.²⁵

Frequently asked questions

How long should it take to fall asleep?

CKS: "The normal time taken to fall asleep (sleep-onset latency) is usually considered to be less than 20 minutes. The average mean sleep latency has been measured to be 11.7 minutes." Adults are generally advised 7 to 9 hours, and "with ageing the number of awakenings increases and total sleep time decreases".⁶

Do sleep supplements work?

The trials in the table report gains measured in minutes or questionnaire points, in groups from 8 to 1,683 people; the largest measured effects belong to CBT-I and to moving caffeine out of the afternoon. Read the row for what was measured, then the page for who was studied and at what dose.^1,9

Can I catch up on sleep at the weekend?

The NHS advice is not to: "do not sleep in after a bad night's sleep – stick to your regular sleeping hours instead".⁵ The UK Biobank finding that regularity predicted mortality more strongly than duration points the same way.⁸

Sources

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