Andrew Huberman (solo): Professor of neurobiology and ophthalmology at Stanford School of Medicine and host of the Huberman Lab podcast, known for science-based health and performance protocols.
What this episode covers
This solo episode reframes cortisol as an energy-deploying hormone rather than simply a stress hormone, and centers on getting its 24-hour circadian rhythm right: high in the morning, low at night. Huberman walks through the underlying biology (the HPA axis, the negative feedback loop, the SCN's light-driven control) and then stacks practical tools to raise morning cortisol (sunlight, hydration, caffeine timing, exercise, cold exposure, grapefruit, licorice) and to lower it at night (dim/red light, starchy carbs, breathing, NSDR, supplements like ashwagandha and apigenin). He closes by distinguishing two patterns of burnout, prescribing different timing-based fixes for each, and tying a healthy cortisol curve to better cognition, sleep, and even longevity.
Recommended on this episode
The guest's own work
ROKA Wind Down Glasses
ROKA (in collaboration with Andrew Huberman)
“I worked in collaboration with ROA glasses to develop what we call the windown glasses. They're not just blue blockers.”— Andrew Huberman
Protocols: An Operating Manual for the Human Body
Andrew Huberman
“I have a new book coming out. It's my very first book. It's entitled Protocols, an operating manual for the human body.”— Andrew Huberman
Also referenced (named, not recommended)
Ashwagandha
various
“ashwagandha. Now, if you look at the literature on ashwagandha, you will see that indeed it can be effective in reducing cortisol levels by anywhere from about 11% to 29%.”— Andrew Huberman
Magnesium Threonate
various
“I tend to take apenine and magnesium 3 and8 about 30 to 60 minutes before I want to fall asleep.”— Andrew Huberman
Alpha-GPC
various
“if you're me some yerba mate plus a big cup of coffee, maybe an alpha GPC every once in a while. I'll do that and then hit the gym really hard”— Andrew Huberman
Big reveals from this episode
- Huberman calls this potentially the single most beneficial episode he's ever made for health and well-being.
- Claims burnout, morning anxiety, and being 'wired and tired' can be mostly or entirely resolved by fixing your cortisol rhythm.
- Bright light in the eyes within the first hour of waking can boost cortisol by up to 50% and is clinically significant for mood.
- He personally eats a pink grapefruit late morning while researching this episode and notices a tangible energy increase.
- Reveals he has taken 50 mg of apigenin nightly for over eight years as part of his sleep stack.
- Identifies two distinct burnout patterns (morning-stress/afternoon-crash vs. morning-sluggish/night-wired) requiring opposite fixes.
- A flattened cortisol curve predicts lower lifespan and worse cancer outcomes; sharper morning peaks correlate with survival.
Worth remembering
- Cortisol is not really a stress hormone; its main job is deploying glucose/energy, especially to the brain.
- You literally wake up because of a rise in cortisol, called the cortisol awakening response (CAR).
- The fastest rise in morning cortisol happens during the 6th-8th hours of sleep, so short sleepers miss part of it.
- For habitual caffeine users caffeine barely raises cortisol but extends its life; non-users get a big cortisol spike.
- Grapefruit inhibits CYP3A4, extending cortisol's life in the bloodstream by 25-50%.
- Black licorice (via glycyrrhizin) potently raises cortisol and is unsafe for people with hypertension or who are pregnant/breastfeeding.
- Carbohydrates act as 'comfort foods' partly because elevated blood glucose suppresses cortisol release.
- The physiological sigh (double inhale through nose, long exhale) is the fastest real-time tool to calm down.
- NSDR / yoga nidra of 11-30 minutes can significantly reduce cortisol levels.
- Chronically elevated cortisol degenerates hippocampal neurons, harming both memory and stress regulation.