I describe the mechanisms by which different wavelengths of light impact the cells, tissues and organs of the human body, and how specifically timed light exposure of specific wavelengths can be used to improve sleep, enhance alertness, modulate hormone levels, and improve mood. I also explain the use of ultraviolet and infrared phototherapies to relieve pain increase testosterone and estrogen levels; improve skin health, appearance and wound healing; and how red light can be used to offset age-related vision loss and provide neuroprotection. Throughout the episode, I describe the mechanisms of light-based therapies and actionable tools that people can use positively impact mental and physical health. Thank you to our sponsors AG1 (Athletic Greens): https://athleticgreens.com/huberman Thesis: https://takethesis.com/huberman LMNT: https://drinklmnt.com/huberman See Andrew Huberman Live: The Brain Body Contract Tuesday, May 17th: Seattle, WA Wednesday, May 18th: Portland, OR https://hubermanlab.com/tour Our Patreon page https://www.patreon.com/andrewhuberman Supplements from Thorne https://www.thorne.com/u/huberman For the full show notes, visit hubermanlab.com. Timestamps (00:00:00) Using Light to Improve Health (00:04:31) The Brain-Body Contract (00:05:17) AG1 (Athletic Greens), Thesis, LMNT (00:09:56) Physics of Light, Electromagnetic Energy (00:12:23) Wavelengths of Light (00:15:38) How Light Penetrates Tissues (00:20:13) Light & the Body: Direct & Indirect Signals (00:28:35) Light, Seasonality & Melatonin (00:33:40) Melatonin: Regulatory & Protective Effects (00:38:49) Tools: Optimizing Melatonin Levels (00:44:49) Sun (UVB light) Exposure, Mating Behavior, Testosterone & Estrogen (00:58:09) Seasonality, Romantic Passion & Testosterone (01:02:13) Tool: Skin Sun Exposure & Testosterone (01:06:13) Light & Improved Pain Tolerance (01:11:55) Protocol: Sun Exposure & Chronic Pain (01:12:48) Tools: Sunlight (UVB), Blue-Light Blockers, Seasonal Affective Disorder (SAD) (01:19:44) Light & Enhanced Immune Function (01:23:30) Tool: Light During Winter Months (01:26:18) Light Therapies: Local vs. Systemic Exposure (01:28:54) Tool: Improving Mood, Timing of Natural & Artificial Light (01:32:44) Light Conditions & Sleep Optimization (01:39:00) Infrared Light, Skin & Wound Healing (01:46:00) Infrared Light Therapy & Skin, Low-Level Laser (Light) Therapy (LLLT) (01:49:20) Infrared Light & Age-Related Vision Loss (01:59:36) Tools: Infrared Panels, Morning Exposure (02:05:22) Infrared Light at Night, Shift Work (02:08:35) Light Flicker Phototherapy & Neuroprotection (02:19:07) Phototherapies for Health (02:20:50) Zero-Cost Support, YouTube Feedback, Spotify Reviews, Apple Reviews, Sponsors, Patreon, Thorne, Instagram, Twitter, Neural Network Newsletter, Brain-Body Contract Title Card Photo Credit: Mike Blabac Disclaimer