Cortisol operates on a 24-hour cycle with four phases. The Huberman Lab episode “How to Control Your Cortisol & Overcome Burnout” shows how understanding your body’s natural cortisol patterns can help you optimize your energy levels and overall health.
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How the Cortisol Circadian Rhythm Works
Andrew Huberman explains that cortisol follows a predictable 24-hour cycle. Elevated morning cortisol is crucial for maintaining energy, staying alert, and supporting a positive mood. Cortisol should surge when you wake and then decline consistently as evening approaches.
Huberman lays out the four specific phases of the cortisol circadian rhythm:
- When you first fall asleep, cortisol levels drop to their lowest point with barely any hormonal activity.
- As you continue sleeping, the hormone starts climbing slightly before surging rapidly during hours six through eight of sleep. This timing aligns with REM sleep, when your brain becomes highly active and needs glucose from your bloodstream for fuel.
- Once you wake up, cortisol activity spikes dramatically, reaching its peak during late morning or around midday.
- As the day progresses, cortisol activity gradually tapers off.
Cortisol gets a bad reputation as the “stress hormone,” but Huberman explains that it’s actually vital for directing glucose and other fuels to tissues requiring the most energy. This corticosteroid hormone serves as your body’s energy management system, distributing glucose to specific areas such as your brain when they face heightened energy demands beyond typical stress situations. Derived from cholesterol, cortisol also supports brain function, mental focus, and your natural wake-up process each morning.
The Hypothalamic-Pituitary-Adrenal (HPA) Axis
The Hypothalamic-Pituitary-Adrenal (HPA) axis governs the cortisol circadian rhythm through an intricate feedback system. Specialized neurons that produce CRH (Corticotropin-releasing hormone) continuously track cortisol levels in your bloodstream. When your cortisol drops low, CRH triggers the release of ACTH (Adrenocorticotropic hormone) from your pituitary gland, which then prompts your adrenal glands to produce cortisol.
When your morning cortisol levels hit their peak, they reach a critical point that initiates a negative feedback mechanism. This process effectively shuts down cortisol production by sending signals to halt further hormone creation. Should your cortisol climb excessively high, your hypothalamus steps in to suppress additional hormone manufacturing.
Huberman mentions that timing your daily activities and technology use correctly is essential for preserving healthy cortisol patterns, which influence your mood, concentration, alertness, and sleep quality. This relates to how the HPA axis functions, since cortisol’s secretion patterns, circadian timing, and feedback controls all operate as integral parts of this system.
Take Control of Your Cortisol Cycle
- You can align your sleep-wake cycle with your cortisol rhythm by establishing a consistent morning routine that incorporates natural light exposure. Getting sunlight soon after you wake up helps reinforce your body’s natural cortisol surge, which enhances your alertness and mood for the entire day. Simple steps like taking a brief outdoor walk or eating breakfast beside a bright window can make a significant difference.
- Establish a screen-free evening routine one hour before bed to reduce blue light’s interference with your cortisol levels. Because screens can throw off your cortisol cycle, develop habits that involve lowering the lights and participating in calming activities like reading a printed book or doing gentle yoga. These practices can improve your sleep quality by working with cortisol’s natural evening decline.
- Keep a journal to monitor your energy and focus patterns throughout the day, which can help you identify connections to your cortisol rhythm. Recording when you feel sharpest or most sluggish allows you to schedule demanding tasks during your natural cortisol peaks while reserving relaxation or less important activities for when your cortisol levels drop. This approach optimizes both your daily productivity and overall well-being.
Learn More About the Circadian Rhythm
To get a better understanding of the rhythm of cortisol and its broader context, check out Shortform’s guide to the Huberman Lab episode “How to Control Your Cortisol & Overcome Burnout.”
To learn more about the circadian rhythm in general, check out The Circadian Code by Satchin Panda. Panda explains that modern habits—such as irregular sleep schedules, late-night eating, and excessive exposure to artificial light—can throw off your circadian rhythm and cause various health problems. He suggests simple adjustments you can make to your daily habits to live in sync with your circadian rhythm and be your healthiest and most energized self.
In our guide to The Circadian Code, we discuss how your circadian rhythm works, what happens when it’s disrupted, and ways you can sync your lifestyle habits to your circadian rhythm. Along the way, we cite scientific research that supports or contradicts Panda’s ideas and bring in other experts’ advice on living in sync with your circadian rhythm.
