How to Take Our Cortisol Stress Test at Home

For this test, you'll have been provided with a sample kits to collect the saliva at home. You'll be required to collect a sample at four set times of the day, the last sample must be collected at midnight.

The accuracy of the test relies on customers collecting samples at these directed times. The laboratory will not be able to process samples that have not been collected at these set times or labelled correctly. Please ensure you read the instructions inside the home test kit box telling you the exact times to collect the samples.

1. Before you begin

To get the most accurate result, please avoid the following in the days leading up to your test:

• Caffeine: Avoid 12 hours before
• Alcohol: Avoid 24 hours before
• Strenuous exercise: Avoid 24 hours before

Do not test if you’re unwell. Please delay your test if you are experiencing any illness, including a cold, cough, fever, stomach bug or infection, or if you are currently taking antibiotics. Even mild symptoms can affect your cortisol levels and skew your results.

Wait until you have been well for at least two weeks before collecting your samples.

Supplements to pause

Some supplements can affect your cortisol levels and may alter your results. Please pause the following for at least 5–7 days before testing:

• Ashwagandha
• Rhodiola
• Liquorice root
• Phosphatidylserine
• High-dose vitamin C

Standard multivitamins are fine to continue taking. If you’re unsure about another supplement, speak to a healthcare professional.

2. Collecting your samples

Choose a day when you’ll have access to a freezer throughout the day. You’ll need to collect four saliva samples at set times.

Collect each sample using the swab provided – hold it in your mouth for two minutes (make sure you haven’t just eaten), then place it in the labelled tube.

Pop each sample straight into the freezer as soon as it’s collected.

You are required to collect a sample at four set times throughout the day:

Sample 1: 6:00 – 10:00 This captures your Cortisol Awakening Response, which peaks shortly after waking.

Sample 2: 11:30 – 12:30 Levels naturally begin to ease off through the late morning.

Sample 3: 16:00 – 20:00 Tracks the gradual decline into the evening.

Sample 4: 23:30 – 00:30 Cortisol reaches its lowest point, supporting sleep and recovery

Samples collected outside these windows, or with incorrect labels, cannot be processed by the laboratory. Please label each tube carefully with the sample number, date and time of collection.

3. Posting your samples

Once you’ve collected all four samples, post them on a Monday to Thursday only (excluding bank holidays) to ensure they reach the laboratory in time for valid analysis. If you collect your samples over the weekend, simply keep them frozen and post at the start of the following week.

The samples will thaw in transit – this is completely normal and won’t affect your results.

1. Remove all four samples from the freezer and check they are correctly labelled
2. Place the samples in the protective sleeve provided
3. Put the sleeve back inside the original test kit box
4. Drop the sealed box at your nearest post box

Common questions

Can I take the contraceptive pill or HRT while testing?

Yes. Oestrogen-containing contraception and HRT do not affect salivary cortisol levels. While oestrogen raises total cortisol in the blood, saliva measures only free cortisol, which remains unchanged. You can complete the test as normal.

I work night shifts. When should I test?

Wait at least 3 days after finishing a night shift before collecting your samples. This allows time for your circadian rhythm to return to a normal day-to-night pattern.

I’ve just returned from a long-haul flight.

Wait at least 3 days before testing to allow your body to settle back into its normal routine and sleep pattern. This will give you the most accurate results