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KnowYou+

Cortisol Blood Test

At-home blood test

Prepaid tracked return · Processed by a CQC-regulated laboratory.

A simple at-home blood test measuring cortisol, a hormone involved in your body’s natural stress response and daily energy cycle.

Want to understand your cortisol level?

The KnowYou+ Cortisol Blood Test measures cortisol, often known as the body’s stress hormone, in your blood.

Cortisol is produced by the adrenal glands and naturally changes throughout the day. It plays a role in your stress response, metabolism, blood sugar regulation and daily sleep–wake cycle.

Your cortisol level can be influenced by many things, including the time of day, sleep, illness, medicines and physical or emotional stress. That is why collecting your sample at the correct time is particularly important for this test.

Important: A single cortisol result cannot diagnose the cause of tiredness, stress, anxiety or another medical condition. Cortisol results should be considered alongside your symptoms, medicines and wider health.

Coming soon

Be the first to know when this test is available.

For adults who want to understand their cortisol level, whether exploring changes in energy or wellbeing, following up a previous result, or testing as part of clinician-led monitoring.

This test measures 6 key hormones linked to menstrual cycle and reproductive health:

  • FSH — Follicle-Stimulating Hormone
  • LH — Luteinising Hormone
  • Prolactin
  • Testosterone
  • Oestradiol
  • Progesterone

Together, these provide a broader picture of hormone patterns and reproductive health.

Collect your sample between 6:00 AM and 10:00 AM, when cortisol levels are naturally highest. If you have an irregular sleep schedule, collect your sample within two hours of waking and include this information on the laboratory request form. If you take biotin supplements, check with your healthcare professional if they have been prescribed for you. Otherwise, avoid biotin for at least 72 hours before testing.

Collect your sample at home, return it using the prepaid packaging provided, and receive your laboratory result securely.

Everything you need to collect and return your sample, including collection materials, instructions and prepaid return packaging.