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Sleep & Insomnia

Improve sleep quality and reset your circadian rhythm with evidence-based protocols from named sleep scientists and researchers.

Every claim below carries an evidence grade. What do these grades mean?

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MATTHEW WALKER, PHD SLEEP

Fix your wake time before you fix your bedtime

the expert's own view, educational, not medical advice, not endorsed by us

  • ModerateWalker puts regularity first among his sleep protocols: going to bed and waking at the same time, including weekends, is the lever he would pull before any supplement
  • ModerateA fixed wake time is the easier half to control, because you can set it, whereas the moment you fall asleep you cannot
  • ModerateRegularity of sleep timing tracks with health outcomes in large cohort studies independently of how long people sleep
  • LimitedThis is protocol guidance from a sleep scientist in a podcast series, not a randomised trial of his specific routine
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EVIDENCE SLEEP

One week of short sleep cuts testosterone

Moderate

In a controlled lab study, 10 healthy young men slept 5 hours a night for one week and their daytime testosterone fell by roughly 10 to 15 percent, a drop the authors compared to 10 to 15 years of aging. The size of the fall tracked with how severely sleep was cut. It is one small study of 10 young men under lab conditions, so read it as a strong signal about short sleep rather than proof about years of real world sleep debt. The action costs nothing: protect the sleep window before you buy anything aimed at testosterone.

SOURCE →
EVIDENCE SLEEP

The best magnesium depends on your goal

Limited

There is no single best magnesium, because no form has strong outcome trials beating the others. Citrate is well absorbed and cheap, and is the sensible general default, with loose stools the usual reason people stop. Glycinate is the gentler option and has a small, subjective-only sleep signal. Oxide is poorly absorbed, roughly 4 percent, and behaves mainly as a laxative, so it is a poor way to raise your magnesium status. L-threonate is mostly preclinical with one small human trial. Food first: about half of US adults fall below the estimated average requirement. See our magnesium forms guide for the full breakdown.

What to buy
NOW Foods Magnesium Citrate 200 mg Tablets ~$15
Thorne Magnesium Bisglycinate ~$32
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EVIDENCE SLEEP

Only one magnesium form is worth taking

Limited

Magnesium glycinate has a small, real, subjective-only sleep benefit: a 2025 randomised trial of 155 people found an effect size of about 0.2 on self-reported sleep quality, with no objective sleep measurement taken. Magnesium oxide is poorly absorbed and behaves as a laxative rather than a sleep aid, so if that is the bottle on your shelf, it is likely doing little for sleep. See our magnesium forms guide for how the other forms compare.

What to buy
Thorne Magnesium Bisglycinate ~$32
SOURCE →
EVIDENCE SLEEP

Mouth taping does not fix your sleep

Unsupported

A 2025 systematic review pooled the ten studies that exist and found no evidence that taping your mouth shut at night improves sleep quality, reduces snoring severity or reshapes your face. Two small studies showed a modest effect in mild sleep apnea only, and the reviewers flagged a real hazard: anyone whose nose is blocked by allergies, a deviated septum or large tonsils can be left unable to breathe properly. There is nothing to buy here. If you snore or wake up unrefreshed, get assessed for sleep apnea instead.

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Tried melatonin or a sleep app and it did not fix things? That is common. Melatonin's evidence is much stronger for shifting your clock (jet lag, shift work) than for general insomnia, and self-tracking can backfire into sleep anxiety. Work down this map, most people are missing one of the big levers (regularity, light, temperature, caffeine and alcohol timing) rather than a supplement.

A
Strong evidence
Consistent sleep and wake time (regularity) Matthew Walker calls regularity king; in large population studies it predicts health outcomes even more strongly than total sleep duration.
Morning light and evening dimness Bright light in the first hour of waking anchors your body clock; dimming lights and avoiding bright overhead light after sunset supports the melatonin rise that starts sleep.
A cool bedroom, or a pre-bed warm bath or shower A 1 to 3 degree drop in core body temperature helps you fall and stay asleep. A cool room, or a warm bath or shower 1 to 2 hours before bed that triggers post-bath cooling, both work.
Cut caffeine and alcohol close to bedtime Caffeine's measured half-life ranges from 1.5 to 9.5 hours across healthy adults, so an afternoon coffee can still be active at bedtime for some people and not others. What sleep labs measured directly is dose: in a crossover trial in 23 healthy young men, 100 mg late did nothing significant, while 400 mg four hours before bed cost about 50 minutes of sleep. Alcohol fragments sleep and suppresses REM in the second half of the night.
CBT-I (Cognitive Behavioral Therapy for Insomnia) The first-line clinical treatment for chronic insomnia, delivered by a sleep-trained therapist; more durable than sleep medication for many people.
B
Promising, evidence evolving
NSDR or a short wind-down practice Non-sleep deep rest or a brief meditation before bed can ease the transition to sleep; helps some people more than others.
Napping done right Short, earlier-in-the-day naps can help energy without hurting night sleep; long or late naps can backfire.
A small supplement 'cocktail' (magnesium, theanine, apigenin) An optional finishing layer, not a foundation. Add one at a time to learn what actually helps you; some people need none at all.
Sleep tracking, used lightly Can help you spot patterns, but obsessive tracking can itself cause sleep anxiety ('orthosomnia'). Use a simple diary if a tracker stresses you out.
C
Emerging or mixed, covered honestly
Melatonin for general insomnia Evidence is much stronger for shifting your body clock (jet lag, shift work) than for treating everyday insomnia. Do not expect it to work like a sedative.
Novelty sleep gadgets and gimmicks Weighted blankets, sleep-tracking rings and similar devices have limited independent evidence for actually improving sleep quality; comfort and consistency matter more than the device.

Most sleep problems are not a willpower problem, they are a light, temperature, timing and habit problem. Regularity (going to bed and waking at the same time) predicts health outcomes even more strongly than total sleep duration, and a handful of levers, morning light, evening dimness, a cool bedroom, and cutting caffeine and alcohol close to bedtime, do most of the work before any supplement enters the picture. Here is the honest map of what helps, ranked by evidence, so you always know your next move if the last thing you tried did not fix it.

Matthew Walker portrait
Matthew Walker
Sleep Scientist · UT Dallas
Gary Brecka portrait
Gary Brecka
Human Biologist · The Ultimate Human
Paul Saladino portrait
Paul Saladino
Physician, Animal-Based Health · Double board-certified MD
Shona Halson
Sleep & Recovery Physiologist, PhD · Associate Professor, Australian Catholic University; former Australian Institute of Sport
Mikhail Varshavski, DO
Family Medicine Physician · Board-certified family medicine
Michael Breus, PhD, ABSM
Clinical Psychologist, Sleep Medicine Specialist (‘The Sleep Doctor’) · Independent practice, former WebMD Sleep Expert
Shelby Harris, PsyD, CBSM, DBSM
Licensed Clinical Psychologist, Board-Certified in Behavioral Sleep Medicine · Associate Professor of Neurology and Psychiatry, Albert Einstein College of Medicine

Compare experts on Sleep & Insomnia

Andrew Huberman vs Bryan JohnsonAndrew Huberman vs Gary BreckaAndrew Huberman vs Matthew WalkerAndrew Huberman vs Michael Breus, PhD, ABSMAndrew Huberman vs Paul SaladinoAndrew Huberman vs Satchin PandaAndrew Huberman vs Shelby Harris, PsyD, CBSM, DBSMAndrew Huberman vs Shona HalsonBryan Johnson vs Gary BreckaBryan Johnson vs Matthew WalkerBryan Johnson vs Michael Breus, PhD, ABSMBryan Johnson vs Paul SaladinoBryan Johnson vs Satchin PandaBryan Johnson vs Shelby Harris, PsyD, CBSM, DBSMBryan Johnson vs Shona HalsonGary Brecka vs Matthew WalkerGary Brecka vs Michael Breus, PhD, ABSMGary Brecka vs Paul SaladinoGary Brecka vs Satchin PandaGary Brecka vs Shelby Harris, PsyD, CBSM, DBSMGary Brecka vs Shona HalsonMatthew Walker vs Michael Breus, PhD, ABSMMatthew Walker vs Paul SaladinoMatthew Walker vs Satchin PandaMatthew Walker vs Shelby Harris, PsyD, CBSM, DBSMMatthew Walker vs Shona HalsonMichael Breus, PhD, ABSM vs Paul SaladinoMichael Breus, PhD, ABSM vs Satchin PandaMichael Breus, PhD, ABSM vs Shelby Harris, PsyD, CBSM, DBSMMichael Breus, PhD, ABSM vs Shona HalsonPaul Saladino vs Satchin PandaPaul Saladino vs Shelby Harris, PsyD, CBSM, DBSMPaul Saladino vs Shona HalsonSatchin Panda vs Shelby Harris, PsyD, CBSM, DBSMSatchin Panda vs Shona HalsonShelby Harris, PsyD, CBSM, DBSM vs Shona Halson
Melatonin is not helping me fall asleep, what should I try instead?▾
Melatonin's evidence is stronger for circadian-shift use (jet lag, shift work) than for general insomnia. Try the behavioral levers first: a consistent sleep and wake time, morning light, a cool bedroom, and cutting caffeine and alcohol close to bedtime. For persistent insomnia, CBT-I delivered by a trained therapist is the first-line clinical treatment.
How much does caffeine really affect sleep if I fall asleep fine?▾
Falling asleep fine does not settle it, but the size of the dose matters more than the hour. In a 2025 sleep-lab crossover in 23 healthy young men, 100 mg late had no significant effect on measured or self-reported sleep at any timing tested, while 400 mg four hours before bed cost 50.6 minutes of total sleep. Caffeine's half-life also varies widely between people, from 1.5 to 9.5 hours, which is why a single cutoff time does not work for everyone.
Is a nap going to ruin my night sleep?▾
It depends on timing and length. Short naps earlier in the day generally do not hurt night sleep and can help energy; long or late-afternoon naps are more likely to make it harder to fall asleep at night.
What is CBT-I and is it better than sleeping pills?▾
CBT-I (Cognitive Behavioral Therapy for Insomnia) is a structured, therapist-led program that retrains the behaviors and thoughts that maintain insomnia. It is the first-line clinical recommendation for chronic insomnia and tends to be more durable than sleeping pills, without the dependency risk.
Do I need a whole supplement stack to sleep well?▾
No. The behavioral basics, regularity, light, temperature, and caffeine and alcohol timing, do most of the work. Supplements like magnesium, theanine or apigenin are an optional finishing layer; add one at a time, and know that some people need none at all.
My sleep tracker makes me more anxious about sleep, what should I do?▾
This is a known effect called orthosomnia, where obsessively monitoring sleep data itself worsens sleep. If your tracker stresses you out, stop using it or switch to a simple written sleep diary instead.

Experts behind Sleep & Insomnia protocols

Follow to get their new protocols in My Protocols
Gary Brecka portrait Contested claims

Gary Brecka

Human Biologist
9 protocols · 3M
Matthew Walker portrait

Matthew Walker

Sleep Scientist
5 protocols · 183K

Michael Breus, PhD, ABSM

Clinical Psychologist, Sleep Medicine Specialist (‘The Sleep Doctor’)
2 protocols
Paul Saladino portrait

Paul Saladino

Physician, Animal-Based Health
2 protocols · 2.8M

Mikhail Varshavski, DO

Family Medicine Physician
1 protocol

Shelby Harris, PsyD, CBSM, DBSM

Licensed Clinical Psychologist, Board-Certified in Behavioral Sleep Medicine
1 protocol

Shona Halson

Sleep & Recovery Physiologist, PhD
1 protocol
New protocols for this condition, first
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