SleepResearch
How Much REM Sleep Do You Need? (and How to Get More)
Healthy adults spend about 20 to 25% of the night in REM sleep, roughly 1.5 to 2 hours. A minutes table, how far to trust your tracker, and what actually moves it.
11 min read
26 Articles
Research
Dive into the science behind NSDR, sleep, and relaxation with evidence-based research and studies.
GuidesResearch
7 Types of Rest: Which One You're Missing and How to Get It
Sleep is only one kind of rest. The seven types at a glance, a quick self-check for the one you're missing, and an honest look at where the idea comes from.
12 min read
SleepResearch
Is Rain White Noise? What Colour Rain Really Is (and Does It Matter?)
Strictly, rain isn't white noise: its sound shifts with how hard it falls and what it hits. Why it still gets called that, and what matters for sleep.
7 min read
GuidesResearch
Somatic Exercises: 7 Gentle Ones and What the Evidence Says
Seven gentle somatic exercises for stress and tension, each with simple steps and a plain line on what the research shows, and what it doesn't.
12 min read
ResearchFocus
432 Hz: What the Evidence Says About the "Healing" Frequency
432 Hz is ordinary music tuned about a third of a semitone lower. What the small trials found, where the claims come from, and why the music matters more.
11 min read
SleepResearch
How Much Deep Sleep Do You Need? Normal Amounts for Adults
Adults typically get about 10 to 20% of the night as deep sleep, roughly 40 to 110 minutes. What's normal, how age changes it, and how far to trust a tracker.
9 min read
SleepResearch
Hypnagogia: What Happens at the Edge of Sleep
Hypnagogic hallucinations are sights, sounds or sensations as you drift off. They're common and usually not a concern. What causes them and when to see a GP.
10 min read
SleepResearch
What Is Core Sleep? Apple Watch Sleep Stages Explained
Core sleep is Apple Watch's label for light sleep, stages N1 and N2. How much is normal, how it compares with deep and REM sleep, and how far to trust the watch.
9 min read
SleepResearch
Is 6 Hours of Sleep Enough? What Research Says (and 5 or 7)
For most adults, no. Two weeks of 6-hour nights impaired thinking while sleepiness ratings barely rose. What the research says about 5, 6 and 7 hours.
13 min read
NSDRHubermanSleep
Contrast Therapy Benefits: What the Research Shows
Contrast therapy helps recovery after hard exercise more than resting does. Heart, mood and metabolism claims mostly come from sauna-only or cold-only studies.
13 min read
NSDRFocusBreathwork
Zone 2 Cardio Benefits: The Calm Path to Better Health
Zone 2 cardio benefits, sized honestly: what the trials show for fitness, blood pressure and blood sugar, why it feels calm, and how to find your zone.
13 min read
NSDRSleepFocus
Magnesium Glycinate vs Citrate: Which One to Take
Citrate beats magnesium oxide for absorption; glycinate's data are thinner. Glycinate suits bedtime and a sensitive stomach, citrate constipation. Stay at or under 350 mg a day.
12 min read
NSDRSleepBreathwork
Stages of Sleep Explained: What Your Brain Does Each Night
The four stages of sleep, N1, N2, N3 and REM, run in cycles of about 90 minutes. What each one does, how long it lasts, how age changes it, and what protects it.
12 min read
NSDRSleepBreathwork
Melatonin Side Effects: What's Common, Rare and Still Unknown
Most melatonin side effects are mild and uncommon. How often each shows up, how dose and labels change the picture, and what a 2025 heart failure study did and didn't show.
12 min read
NSDRHubermanSleep
Caffeine Half Life: How Long It Really Stays in You
Caffeine's half-life averages about 4 hours, with a range of 2 to 8. How much of a noon coffee is left at bedtime, what stretches it, and when to stop.
14 min read
NSDRHubermanSleep
Apigenin for Sleep: Does It Work & How to Use It
Apigenin is usually taken as 50 mg before bed. No trial has tested it alone, the chamomile trials are mixed, and a 2026 blend trial found no sleep benefit.
12 min read
NSDRHubermanSleep
Glycine for Sleep: How It Works, Dosage & When to Cycle
Glycine for sleep is taken as 3 g before bed. Small trials found better-rated sleep and faster sleep onset, the mechanism is from rats, and cycling is Huberman's habit.
13 min read
SleepHubermanSupplements
Magnesium Threonate for Sleep: What the Research Shows
Two small, industry-funded trials found magnesium threonate helped some sleep measures and not others. The 145 mg dose, timing, side effects and how it compares with glycinate.
16 min read
SleepHubermanSupplements
L-Theanine for Sleep: 5 Ways to Use It (Dosage + Timing)
L-theanine may help you settle into sleep without sedation. Trial doses and timing, five ways to use it, who should skip it, and who paid for the studies.
16 min read
NSDRFocusDopamine
Pomodoro Technique + Binaural Beats: The Productivity Stack
No study has tested Pomodoro and binaural beats together. Here is what each half's research shows, which frequencies to try, and a one-week test against silence.
11 min read
NSDRFocusDopamine
Best Free Focus Music for ADHD: Ranked by Evidence
Which focus sounds help ADHD? White noise gives a small boost in studies, brown noise is untested in ADHD and binaural beats haven't helped. Free picks, ranked.
13 min read
NSDRFocusDopamine
Lofi Binaural Beats: Does the Combination Help Focus?
Lofi on its own didn't change study scores, binaural beats have mixed results, and nobody has tested the pair for focus. What the research shows, and how to set up the mix.
12 min read
NSDRSleepBreathwork
Sympathetic vs Parasympathetic: Key Differences Explained
How the sympathetic and parasympathetic branches differ in nerves, messengers, reach and speed, what norepinephrine does, and which ways to calm down have real evidence.
12 min read
NSDRSleepBreathwork
Vagus Nerve Stimulation: 3 Techniques Worth Trying
Medical vagus nerve stimulation, its approved uses and devices, plus slow breathing, cold water and humming ranked by the studies behind them.
10 min read
FocusGuidesResearch
Ideal Focus Session Length: Huberman's 90-Minute Limit
Huberman caps a focus session at 90 minutes, warm-up included, then 10 to 30 minutes of defocus. How to run one, how many a day, and what the evidence says.
11 min read
HubermanNutritionResearch
Huberman Fasting Protocol: His 2 Core Rules
Huberman's two fixed fasting rules, where the 8-hour window came from, what breaks a fast, and what human trials since 2021 found.
12 min read