The cortisol day profile.
Five saliva samples across one day show how your organism responds to strain.
The key biomarker of the stress axis.
Cortisol is the central hormone of the hypothalamic pituitary adrenal axis. It regulates the activation of the organism and follows a fixed daily rhythm: a rise within the first 30 to 60 minutes after waking, a continuous decline across the day and a low level in the evening. This rhythm changes under sustained strain, often before people notice a change themselves.
What cortisol does in the body
Cortisol controls not only the stress response but also energy availability, metabolism, immune function and the sleep-wake rhythm. Its concentration therefore naturally varies throughout the day.
- Typically the highest value in the morning (awakening response)
- Steady decline during the day until evening
- Chronic strain can alter the pattern
- Single values say little, the trajectory matters
What a day profile can show
- Typical cortisol trajectory across four time points
- Indications of too flat or missing recovery phases
- Clues about the dynamics of strain and recovery
- A basis for further interpretation in conversation
What it does not do
A cortisol day profile is not a diagnostic tool and does not replace a medical examination. It does not explain a single cause and does not provide isolated treatment recommendations. Results are always interpreted in context with further information.
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H4I provides interpretation and orientation. This website is not a substitute for medical examination or treatment.