Circadian
Circadian rhythm and biological clock optimization
Interventions
Delayed Caffeine Protocol
Delaying morning caffeine 90-120 minutes after waking to optimize alertness and avoid afternoon crashes
Blue Light Blocking Glasses
Wearing glasses that filter blue wavelengths in the evening to protect melatonin production and support natural circadian rhythm
Sleep Environment Optimization
Optimize temperature, light, sound, and bedding to create the ideal physical environment for deep, restorative sleep
Vitamin D Lamp (UVB Light Therapy)
UVB light devices that stimulate natural vitamin D production in the skin, providing an alternative to sun exposure or oral supplementation
SAD Lamp (Bright Light Therapy)
Bright light therapy devices that emit 10,000 lux to treat Seasonal Affective Disorder (SAD) and regulate circadian rhythms
Melatonin
The body's sleep hormone, proven effective for improving sleep onset, jet lag recovery, and circadian rhythm optimization
Studies
The Human Circadian Clock Entrains to Sun Time
Human circadian rhythms are primarily synchronized by natural daylight, with wake times tracking sunrise times across different longitudes.
Blue-Enriched White Light in the Workplace Improves Self-Reported Alertness, Performance and Sleep Quality
Workers exposed to blue-enriched light during the day reported better alertness, mood, and nighttime sleep quality compared to standard white light.
A controlled trial of timed bright light and negative air ionization for treatment of winter depression
Morning bright light therapy is highly effective for seasonal affective disorder, with early morning exposure (soon after waking) showing best results.
Stability, Precision, and Near-24-Hour Period of the Human Circadian Pacemaker
The human circadian clock runs on a near-24-hour cycle and requires daily light exposure to stay synchronized with the external day-night cycle.
Time-Restricted Feeding without Reducing Caloric Intake Prevents Metabolic Diseases in Mice Fed a High-Fat Diet
Mice eating within an 8-hour window were protected from obesity and metabolic disease despite consuming the same calories as mice eating around the clock.
Effects of thermal environment on sleep and circadian rhythm
Heat exposure during sleep significantly reduces slow-wave sleep (deep sleep) and REM sleep, while a cool environment facilitates the natural drop in core body temperature needed for sleep onset.
Early Time-Restricted Feeding Improves 24-Hour Glucose Levels and Affects Markers of the Circadian Clock, Aging, and Autophagy in Humans
Early time-restricted eating (eating window ending by 3pm) improved glucose levels, insulin sensitivity, and markers of autophagy.
Circadian Physiology of Metabolism
Comprehensive review establishing that circadian clocks in metabolic organs regulate nutrient processing, and disrupting these rhythms contributes to metabolic disease.
Seasonal affective disorder: A description of the syndrome and preliminary findings with light therapy
The landmark study that first described Seasonal Affective Disorder and demonstrated that bright light therapy could effectively treat winter depression.
Coffee, caffeine, and sleep: A systematic review of epidemiological studies and randomized controlled trials
Systematic review supporting strategic caffeine timing aligned with circadian rhythms for optimal alertness without sleep disruption.
Melatonin for the prevention and treatment of jet lag
Melatonin is remarkably effective for preventing or reducing jet lag, particularly when crossing 5 or more time zones and traveling eastward.
The durations of human melatonin secretion and sleep respond to changes in daylength (photoperiod)
Landmark study showing humans retain photoperiod sensitivity - melatonin secretion duration changes with light exposure patterns, affecting sleep architecture.
Association between exposure to light at night (LAN) and sleep problems: A systematic review and meta-analysis of observational studies.
Exposure to light at night is associated with a 22% increased prevalence of sleep problems, with indoor light exposure (74% increase) far more disruptive than outdoor light pollution (19% increase).
Experts
Podcast Episodes
Using Light for Health
with Andrew Huberman
Dr. Matthew Walker: The Science & Practice of Perfecting Your Sleep
with Matthew Walker
Sleep Toolkit - Tools for Optimizing Sleep & Sleep-Wake Timing
with Andrew Huberman
Essentials: Optimizing Workspace for Productivity, Focus & Creativity
with Andrew Huberman
Gary Brecka, Dr. Will Cole & Dr. Tara Swart Bieber Live at the Wellness Oasis Event
with Dr. Will Cole, Dr. Tara Swart Bieber
Andrew Huberman — Optimizing Sleep, Enhancing Performance (2023)
with Dr. Andrew Huberman
Matt Maruca - Circadian Light Masterclass: Debunking Sunglasses & Blue-Light Hysteria
with Matt Maruca
Light As Medicine, Metabolic Typing, COVID Controversies, Polar Bear Fitness, Healing Yourself With Laughter & More With Life Network Expert Dr. Leland Stillman
with Leland Stillman
How Nature & Other Physical Environments Impact Your Focus, Cognition & Health | Dr. Marc Berman
with Andrew Huberman
Essentials: The Science & Practice of Perfecting Your Sleep
with Andrew Huberman
#039 Dr. Satchin Panda on Practical Implementation of Time-Restricted Eating & Shift Work Strategies
with Dr. Satchin Panda
Optimizing Daily Habits: Snacking, Movement, Light Exposure, and More Wellness Hacks LIFE Network: RAW Podcast #3
with Ben Greenfield
Essentials: Maximize Productivity, Physical & Mental Health With Daily Tools
with Andrew Huberman
Dr. Allison Brager: Improve Sleep Efficiency & Resilience
with Allison Brager
Inside the Mind of the Mad Scientist Rewriting Aging : 1401
with Dr. Theodore Achacoso & Boomer Anderson
How Long Can Humans Really Live… (with Dan Buettner) : 1393
with Dan Buettner
Turn Off Your WiFi Tonight and See What Happens to Your Sleep : 1414
with Andy Mant & Katie Mant
Essentials: Using Science to Optimize Sleep, Learning & Metabolism
with Andrew Huberman
Essentials: Master Your Sleep & Be More Alert When Awake
with Andrew Huberman
AMA #16: Sleep, Vertigo, TBI, OCD, Tips for Travelers, Gut-Brain Axis & More
with Andrew Huberman
AMA #14: 2023 Philanthropy, Evening Routine, Light Therapy, Health Metrics & More
with Andrew Huberman
Essentials: Optimize Your Learning & Creativity With Science-Based Tools
with Andrew Huberman
Essentials: How to Defeat Jet Lag, Shift Work & Sleeplessness
with Andrew Huberman
GUEST SERIES | Dr. Matt Walker: Improve Sleep to Boost Mood & Emotional Regulation
with Dr. Matt Walker
GUEST SERIES | Dr. Matt Walker: How to Structure Your Sleep, Use Naps & Time Caffeine
with Dr. Matt Walker
GUEST SERIES | Dr. Matt Walker: The Biology of Sleep & Your Unique Sleep Needs
with Dr. Matt Walker
Journal Club with Dr. Peter Attia | Effects of Light & Dark on Mental Health & Treatments for Cancer
with Dr. Peter Attia
Matt Maruca – Principles of the Light Diet! Can You Live On Light?
with Matt Maruca
255. Fake Lighting Is Sabotaging Your Natural Rhythm w/ Tristan Scott
with Tristan Scott
221. How to optimize sleep
with Paul Saladino
Your Sunburn Could be a Copper Deficiency
with Matt Blackburn
The Complexities of Natural and Artificial Light Exposure with Dr Alexander Wunsch
with Dr Alexander Wunsch
Circadian Health Tips with Sarah Kleiner
with Sarah Kleiner
Shawn Stevenson - How To Hack Your Sleep With These Habits
with Shawn Stevenson
Dr Andrew Huberman - The Secret Tools To Hack Your Brain
with Dr Andrew Huberman
Ep 119: Benefits of Red Light Therapy + Infrared Sauna with Brian Richards
with Brian Richards
640. Circadian Light Masterclass: Debunking Sunglasses, Sunbathing & Blue-Light Hysteria w/ Matt Maruca
with Matt Maruca
450: The Light Secret: Why Temperature Doesn't Matter in Optimal Infrared Therapy with Connie Zack
with Connie Zack
Infrared, ultraviolet and LED therapy – can lights cure us?
Do SAD Lamps Actually Work?
with Nancy Redd
How to Manage Seasonal Depression
with Amanda Armstrong
5 Ways to Beat Seasonal Depression
with Briarley Horton, Carolyn Williams
The SAD Episode
5 Ways to Get Ahead of Seasonal Depression Now
with Briarley Horton, Carolyn Williams
Vitamin D Expert: The Fastest Way To Dementia & The Dangerous Lie You've Been Told About Sunlight!
with Dr. Roger Seheult
96: Ayurveda for Perimenopause & Menopause: Gut Health, Estrobolome Support, and Anti-Inflammatory Spices
with Dr. Shivani Gupta
139: Cort Christie, CEO of Sperti Sunlamps: Getting Vitamin D From A Lamp?! Boost Immunity & Sleep Better A Novel Product
with Cort Christie
The Biggest Misconceptions about Vitamin D | Episode 247
Sleep, Light, Alarms, Caffeine, Night Shifts, Naps, Sleeping Positions & More With Shawn Stevenson.
with Shawn Stevenson