This test assesses your body’s natural cortisol surge in the first hour after waking, known as the Cortisol Awakening Response (CAR). Cortisol is a key stress hormone that follows a daily rhythm, rising sharply in the morning to help you wake up, feel alert and prepare for the day ahead.
The CAR test focuses specifically on this critical morning window and acts as a short “stress response check” for the body’s stress-regulation system, known as the HPA axis.
Why this test is useful
In healthy individuals, cortisol typically rises by around 50% within the first 30 minutes after waking. When this response is too low or too high, it can be a sign that the body’s stress system is under strain.
An altered CAR has been linked with fatigue, burnout, poor sleep, mood changes and difficulty coping with stress. This test provides insight into stress resilience, circadian rhythm and adrenal function that may not be detected by standard cortisol tests.
How the test works
You collect saliva samples at home using the materials provided.
Samples are collected at specific time points:
immediately upon waking
30 minutes after waking
60 minutes after waking
Two evening samples
Saliva is used because it reflects free, biologically active cortisol and captures rapid changes that occur in the morning.
Timing is critical for accurate results and clear instructions are provided in the kit.
What is measured
This test measures:
Cortisol levels immediately after waking
The rise or fall in cortisol over the first hour
The overall pattern of the Cortisol Awakening Response
Results show whether your response is within the expected range, blunted (low) or exaggerated (high).
Biomarkers measured in this test
- Cortisol (Saliva)
- Cortisone (Saliva)
Who should consider this test
This test may be useful if you:
experience chronic fatigue, burnout or poor stress tolerance
have ongoing sleep issues or unrefreshing sleep
feel “wired but tired” or struggle to get going in the morning
experience anxiety related to upcoming daily demands
are concerned about HPA axis dysfunction
want deeper insight into stress, mood or energy regulation
It is commonly used in the assessment of burnout, seasonal affective disorder (SAD), PTSD, insomnia, depression, chronic pain, autoimmune conditions and blood sugar regulation issues.
Understanding your results
Normal CAR suggests a healthy morning stress response
Blunted (low) CAR may be associated with chronic stress, burnout, fatigue, or disrupted sleep
Exaggerated (high) CAR may be linked with acute stress, anxiety, mood disorders, or metabolic strain
Results are best interpreted alongside symptoms, medical history, and lifestyle factors. Follow-up with a qualified healthcare professional may be appropriate.
Important testing instructions
The first saliva sample must be taken immediately upon opening your eyes, before getting out of bed.
Do not eat, drink, or brush/floss your teeth until after the final sample.
Certain foods (such as bananas, avocados, and fava beans) should be avoided for 48 hours beforehand if advised in your kit instructions.
Returning samples to the lab
It is the user’s responsibility to organise sample returns.
Free courier collection is included with the order and full instructions are provided in the sample collection kit.
Results timeframe
Results are typically available within 2–4 weeks.
Timeframe begins after the laboratory receives your samples.
Important limitations
This test assesses the morning cortisol response only and does not diagnose medical conditions.
Results may be influenced by sleep quality, recent stress, shift work, medications and lifestyle factors.
Abnormal results should not be used to make medical decisions without appropriate professional guidance.
This is a DUTCH Test® developed by Precision Analytical Ltd.
Price includes shipping cost.
***Purchasing this test means you agree to our stated Terms and Conditions and that you understand it is your responsibility to follow up results with your doctor / general practitioner / medical consultant or healthcare practitioner.***