In this Huberman Lab Essentials episode, my guest is Dr. Samer Hattar, PhD, the Chief of the Section on Light and Circadian Rhythms at the National Institute of Mental Health. We discuss how light powerfully shapes mood, sleep, appetite, learning and overall mental health by aligning—or misaligning—our internal circadian clock. We explain practical protocols to support your circadian rhythm, including morning sunlight exposure, dim evening lighting and regular mealtimes. We also discuss strategies to manage jet lag, limit evening screen use, ease seasonal depression and improve focus by syncing light, sleep and food with natural biological rhythms. Episode show notes: https://go.hubermanlab.com/dKJ2cZQ Huberman Lab Essentials are short episodes focused on essential science and protocol takeaways from past full-length Huberman Lab episodes. Watch the full-length episode: https://youtu.be/oUu3f0ETMJQ Watch more Huberman Lab Essentials episodes: https://youtube.com/playlist?list=PLPNW_gerXa4OGNy1yE-W9IX-tPu-tJa7S *Follow Huberman Lab* Instagram: https://www.instagram.com/hubermanlab Threads: https://www.threads.net/@hubermanlab X: https://twitter.com/hubermanlab Facebook: https://www.facebook.com/hubermanlab TikTok: https://www.tiktok.com/@hubermanlab LinkedIn: https://www.linkedin.com/in/andrew-huberman Website: https://www.hubermanlab.com Newsletter: https://www.hubermanlab.com/newsletter *Dr. Samer Hattar* X: https://x.com/samerhattar Instagram: https://www.instagram.com/samerhattar *Timestamps* Disclaimer & Disclosures: https://www.hubermanlab.com/disclaimer