The cortisol awakening response (CAR) kit uses a timed series of saliva samples. Getting the timing and tube labels right matters for following the collection protocol. This guide summarises the Saliva Cortisol Awakening Response instructions and the CAR Collection Kit instructions; keep the full PDFs and your kit directions beside you while collecting.
Set up the six tubes the night before
Check the test code on your requisition form and confirm that it matches the CAR panel. The guide calls for six saliva samples. The night before, lay out the tubes, write your name on each one and number them 1 through 6. Stay well hydrated, but avoid excessive fluids.
Collect the first three samples after waking
- Tube 1, upon waking: ideally collect before getting out of bed. Sit up and fill the tube about halfway, which the guide says should take around 5–10 minutes. Secure the cap and write the collection date and time on tube 1.
- Tube 2, 30 minutes after waking: collect at the time specified in the guide, then cap and label the tube with the date and time.
- Tube 3, 60 minutes after waking: collect, cap and label it in the same way.
Until the first three samples are complete, do not eat, brush your teeth or have beverages or food. The guide allows water. After the first sample, rinse your mouth with water as directed, but wait until the first three samples are done before brushing your teeth or eating.
Collect the remaining samples later in the day
Collect tube 4 just before lunch, tube 5 just before dinner and tube 6 just before bed. The guide says not to eat, drink anything other than water, or brush your teeth for at least two hours before these later collections. Label every tube with your name, date and actual collection time.
Fill, store and return the samples
Each sample should fill its tube at least halfway, not counting bubbles. Let saliva pool in your mouth before transferring it. The guide suggests smelling food, yawning or gently pressing your tongue against your teeth to help saliva flow. Bag the samples only after labeling them, seal the bag and refrigerate or freeze it until shipping. Freeze any samples that will not be shipped within 24 hours.
If you make a collection mistake, the PDF says to rinse the tube with hot water without soap, shake out the remaining water, air-dry it and restart at the appropriate time. If you are unsure how to restart, contact the laboratory for guidance.
Complete the paperwork, place the bagged samples and documents in the kit box, then use the return packaging and carrier specified for your kit. For all timings and details, refer to the full CAR collection instructions.
Related CAR tests
- Male Cortisol Awakening Response (CAR) Test (LC-MS/MS)
- Female Cortisol Awakening Response (CAR) Test (LC-MS/MS)
This article covers specimen collection only. It is not medical advice or an interpretation of test results. Follow the kit instructions and contact the laboratory or a qualified healthcare professional if you are unsure about collection or medicines.