Waking
Your circadian system is already preparing the body for the day.
Visual field guide 03Hormones + sleep
Cortisol should rise.
It should also know
when to fall.
Cortisol is not the enemy. Its daily rhythm helps you wake, mobilise energy and respond to demand. Better sleep is less about “lowering cortisol” and more about giving your body clock clear signals for day and night.
See the 24-hour rhythm ↘A calm, 4-minute visual guide
HIGHERready for day
LOWERready for night
WAKENOONBED
THE USEFUL SHAPEA strong morning signal, then a long gentle descent.
THE DAILY PATTERNA wave, not a
A wave, not a
good-or-bad number.
Cortisol is released in pulses. The exact height varies by person and day; the broad timing is the useful part to understand.
RELATIVE CORTISOL
WAKE9 AMNOON6 PMBED
Morning crest
Cortisol is normally highest around the sleep–wake transition.
Daytime slope
Levels usually ease down while pulses continue in the background.
Night-time low
A lower-alerting biological night supports the transition into sleep.
IMPORTANT DISTINCTION
Morning light does not work like a cortisol button.
Light entering the eyes tells the brain’s master clock that day has begun. That timing signal helps anchor many rhythms—including sleep and wake timing. Your morning cortisol rise is largely circadian and begins around the habitual sleep–wake transition.
ANCHOR THE MORNINGLet your eyes
Let your eyes
find the day.
For a typical daytime schedule, morning light tends to move the body clock earlier; bright evening light tends to move it later.
Go outside
Get daylight soon after waking when practical. Outdoors is usually much brighter than a window-lit room—even on a cloudy day.
Look around, not at the sun
Normal outdoor exposure is the goal. Never stare directly at the sun; follow sun-safety advice for your location and eyes.
Repeat most days
A regular wake time plus morning daylight is a clearer time signal than an occasional heroic dose of brightness.
Shift worker?
Your “morning” is tied to your planned wake period, not necessarily sunrise. Light timing can have the opposite effect at different biological times, so personalised advice may help.
PROTECT THE DESCENTMake evening feel
Make evening feel
different from day.
You do not need a perfect routine. A few repeated contrasts—bright to dim, active to quiet, fed to finished—can make bedtime easier to recognise.
Dim the “daytime” signal
In the hour before bed, lower room brightness and avoid intense screen light when it keeps you alert. Bright evening light can delay the body clock.
Finish large meals earlier
Avoid heavy or large meals within a few hours of bedtime. A light snack is okay if hunger would otherwise keep you awake.
Count back from bedtime
CAFFEINEBED
Caffeine can interfere with sleep for hours. If sleep is fragile, move your last coffee or tea earlier and notice your own response.
Give the nervous system a runway
Quiet reading, a warm shower, gentle stretching or slow breathing can create a repeatable bridge from doing to resting.
A SIMPLE DAILY EXPERIMENTFour anchors.
Four anchors.
Try them for a week.
Keep the plan small enough to repeat. Consistency teaches the clock more than intensity.
Aim for roughly the same time, including weekends.
Pair morning light with a short walk or first drink.
Leave digestion room before bed; adjust for comfort.
Choose a simple cue you can repeat nightly.
The “three hours” is a practical starting point for a large meal, not a cortisol prescription or universal rule.
WHEN HABITS ARE NOT THE WHOLE ANSWERDo not diagnose cortisol
Do not diagnose cortisol
from a feeling.
Persistent insomnia
If sleep trouble lasts for months or affects daytime life, ask about evidence-based insomnia care. CBT-I is more than sleep hygiene.
Possible sleep disorder
Loud snoring, gasping, breathing pauses, irresistible daytime sleepiness or restless legs deserve clinical assessment.
Possible hormone disorder
True cortisol excess or deficiency needs medical testing. Progressive features such as unusual bruising, purple stretch marks, marked weakness or unexplained weight change need a clinician—not a home cortisol “reset.”
SOURCESEvidence behind