Wired at night. Exhausted during the day. Snapping at things that wouldn't normally bother you. If that pattern sounds familiar, cortisol — your body's main stress hormone — is worth a proper look.
What cortisol actually does
Cortisol isn't just "the stress hormone" in a bad way — it's essential. It follows a natural daily rhythm, rising sharply in the morning to help you wake up and get going, then gradually falling through the day so your body can wind down at night. Chronic stress, poor sleep, and certain lifestyle patterns can disrupt that rhythm, and when they do, it shows up in how you feel.
Signs your cortisol rhythm might be off
- Feeling "wired but tired" — exhausted all day, then unable to switch off at night
- Waking up still feeling flat, even after what should be enough sleep
- Increased irritability or a shorter fuse than usual
- Energy crashes at odd times of day
- Feeling like your stress response is stuck "on"
Why timing matters when testing cortisol
Because cortisol naturally rises and falls throughout the day, when you test it changes what the result actually tells you. That's why we offer two options:
Cortisol (9am) checks your level at the point it should naturally be at its highest — useful for seeing whether your morning peak is behaving as it should.
Cortisol (random) gives a general snapshot at any time of day, useful as a broader check without needing to time your test precisely.
What happens after your result
Your result comes with an expert review explaining what it means in the context of your symptoms — not just whether the number falls inside a standard range.
If cortisol is only part of the picture, our fatigue and energy testing page covers the other common causes of exhaustion worth ruling out alongside it.
Ready to check your levels? Book your test, or speak to us first if you're not sure which timing is right for you.
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