The Cortisol Awakening Response (CAR) is a sharp morning surge in cortisol levels within the first hour of waking up.
Cortisol has a well-known 24-hour cycle, with highest levels in the morning that continuously decline throughout the day.
However, CAR specifically focuses on this morning surge, and looks for the peak around 30-45 minutes after you wake up.
It's a normal healthy behavior that depends on several factors including gender, age, sleep duration, alcohol consumption, daily routine, contraceptives and menopausal status.
Using six simple, easy-to-collect saliva samples, the cortisol awakening response test will measure cortisol levels within 24 hours: three samples in morning (at wake up, at 30 and 60 minutes) and other three at noon, evening, and night. The results will be plotted on a 24-hour time trend to show your daily response.
We also offer a 24-hour cortisol test (4x) or an AM-PM cortisol saliva test (2x).
Our At-Home Cortisol Awakening Response Test is easy, fast, reliable, and requires just a few steps:
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The stress hormone cortisol has a well defined 24-hour circadian rhythm.
Plot below shows how the levels appear when plotted over time.
The peak on the left, around 30-60 minutes of waking is a characteristic of healthy cortisol levels.
This sudden rise when cortisol levels almost double as soon as we wake up is called Cortisol Awakening Response.
When zoomed in this area, they look like the sketch below:
Note the peak at S1'' around 45 minutes. The goal of the Cortisol Awakening Response Test is to capture this peak by collecting samples around this peak.
First saliva sample is collected right after you wake up (between 0 to 15 minutes at S1), second sample at 30 minutes (near S1' and S1'') and a third sample at 60 minutes (around S1''').
Because the levels change so fast, one has to be careful about collecting them as soon as they wake up (not when you get out of the bed, but when you realize you are awake).
The remaining three saliva samples are collected at noon, evening and night.
Because cortisol levels do not change as significantly (but steadily drop), the timings of these three later samples do not need to be as precise.
All six samples are necessary to generate the 24 hour plot as seen in the first graph above. Full plot is essential since under certain rare health conditions (e.g., those related to pituitary gland disorders) levels may start to rise later in the day.
The most common complain when collecting samples for the Cortisol Awakening Response test is the difficulty in producing and collecting saliva.
Here are few tips to help:
Do not brush, eat or wash 1-2 hours before collection; blood from gums and food might interfere with the results.
If you are bleeding or have gum issues, try collecting another day.
Please make sure to not stress out; plan ahead and pick a regular day to ensure it reflects your routine. Keep hydrated during the day.
You don't need to collect the whole tube (5 ml); 1-3 ml without bubbles should be sufficient.
Try to imagine your favorite food (e.g., pizza always helps, but thinking of your favorite food can help produce more saliva).
Smelling a lemon or other savory foods can also help.
It's normal if it takes five to ten or fifteen minutes to collect the sample (your results will be an average of this time).
If you are not satisfied with your samples, you can always wash the tubes and recollect another day.
Disruptions in the body's natural cortisol circadian rhythm (i.e., the 24-hour trend) may result from several factors such as chronic stress, burnout, sleep disturbances, or disorders affecting your adrenal glands (that produce these hormones).
Chronically high cortisol levels can lead to weight gain, particularly around the abdomen.
High cortisol levels may also add to muscle loss, immune suppression, fluid retention, and bloating.
On the other hand, low cortisol levels may cause fatigue, weakness, sluggishness, and reduced energy.
Measuring cortisol levels throughout the day can help identify abnormalities in cortisol production and regulation.
Persistently elevated cortisol may indicate Cushing syndrome, while abnormally low cortisol may suggest adrenal insufficiency, including Addison's disease.
A cortisol test checks cortisol levels at different times of the day to give insights into the body's natural cortisol rhythm and the functioning of the hypothalamic-pituitary-adrenal (HPA) axis.
A Cortisol Awakening Response helps further zoom into the most important part of this 24-hour trend by collecting multiple samples during this sharp rise in the morning.
This information can help identify potential hormonal imbalances and guide further evaluation of adrenal health.
Although CAR is highly reproducible but studies show several factors can affect the sharp rise in morning cortisol levels.
The goal might not always be to see the highest or lowest value, but a trend and peak values compared to the baseline.
Factors known to affect CAR values:
Age: The peaks are higher in youth but reduce with age.
Gender: Young women tend to have higher peaks than men.
Smoking is known to reduce the peak levels.
Sleep duration might also impact CAR values (shorter sleep might give sharper peak).
Time of waking up is normally not a factor in the CAR trend and area under the curve of the plot.
Some studies suggest taking contraceptives can lower the peak of the cortisol curve.
Other factors include: female reproductive factors such as menstrual cycle phase; a number of physical and mental health conditions including persistent pain, burnout, cardiovascular, autoimmune, allergies and psychiatric diseases; issues with adrenal and pituitary glands.
A: Except New York our tests are available in all 49 states and Canada. State regulations in NY do not allow us to ship the tests to their residents and lab may not be able to test them if collected in NY.
A: The cortisol awakening response test kit contains six tubes for sample collection, instructions on how to collect the samples, and a form requesting basic information including date and time of collection. The directions are straightforward and easy to follow.
A: As per USPS, most CAR test kits are delivered within 3-5 business days. After you ship the sample and it is received by our lab, you get the results within 10-12 business days.
Orders within US include a prepaid return envelope. However, orders from outside US might need to find a way to return the sample back to the lab. The kit will include all the necessary paperwork for cross-border shipping.
A: The report with your test results will be easy to understand and will have all the necessary details. It will mark your cortisol levels on a healthy range for the time of the day and will specify what are the expected low and high ranges. It will briefly discuss what your numbers mean and next steps you should take to maintain healthy levels.
The report will clearly highlight very high levels, e.g., for Cushing's disease or very low levels, as seen in people with Addison's disease (i.e., hypoadrenia).
A: You can use HSA (or FSA/MSA/HRA) accounts to pay for the tests since these are prescription tests (for further confirmation, please check the IRS publication#969). However, please make sure you are not going outside your specified max and min deductible limits. We do not have the capability to process the insurance claim. Since insurance plans vary for individuals we can not guarantee your HSA payment will always be processed by your plan. We suggest talking to your insurance provider if you have any questions.
A: Measuring cortisol levels using saliva is a well researched and documented procedure. It is one of the best way to testing cortisol levels wherever multiple samples are required.
The variations in results are mainly from two sources: the way samples are collected and the variation from lab-to-lab. Levels are highest in the morning, when we are most energetic, and then drop during the day.
To minimize this variation, you should collect the sample without eating, brushing, or putting anything else in your mouth that might contaminate the sample.
To minimize the variation from labs, we have partnered with CLIA-certified labs that are regulated by the states and Centers for Medicare and Medicaid Services (CMS). Many tests from our labs are FDA approved to ensure they meet regulatory requirements. Additionally, the College of American Pathologists (CAP) requires inter-laboratory tests to ensure the ranges established by each lab do not drift or are not out of acceptable ranges. This is done by regularly testing reference samples between different labs. Finally, the labs test thousands of samples for different age groups and health conditions, and have well established reference data to compare your results against this large pool.
A: Unfortunately, no. As a lab test provider we can only test and report the data from your sample. We are not authorized to provide any medical recommendations. But we strongly encourage you to discuss the results with your doctor for next steps.
Understand Your Daily Energy Levels: Cortisol plays an important role in regulating energy, alertness, and the body's natural sleep-wake cycle. The cortisol awakening response (CAR) measures how cortisol levels change shortly after waking. Our convenient at-home Cortisol Awakening Response Test helps you better understand your body's morning cortisol pattern and its relationship to your daily energy rhythm.
Explore Your Body's Response to Stress: Prolonged physical or emotional stress can affect cortisol regulation, potentially influencing sleep, mood, metabolism, and weight management. Our at-home adrenal cortisol test provides valuable insights into your cortisol patterns, helping you better understand your body's stress response and make informed decisions about your health and lifestyle.
Gain Insights into Weight Management and Hormonal Balance: Cortisol influences metabolism, blood sugar regulation, and how the body stores and uses energy. Persistently elevated cortisol levels can contribute to weight gain, particularly around the abdomen. Testing your cortisol pattern can help identify unusual hormone levels that may warrant further evaluation, especially when accompanied by unexplained weight changes, fatigue, or other symptoms.
Evaluate Your Natural Cortisol Rhythm: Cortisol normally follows a daily circadian rhythm, rising around the time of waking and gradually declining throughout the day. Disruptions in this pattern may be associated with stress, sleep disturbances, or certain hormonal conditions. A diurnal cortisol test helps assess these fluctuations and provides useful information about the functioning of the hypothalamic-pituitary-adrenal (HPA) axis. Abnormal results may indicate the need for further testing for conditions such as Cushing syndrome or adrenal insufficiency, including Addison's disease.
Take a Proactive Step Toward Better Health: Understanding your hormone patterns can be an important part of managing your overall well-being. The convenient, affordable at-home cortisol test from RxHomeTest.com provides insights into your body's cortisol regulation without requiring a traditional laboratory visit for sample collection. Use these results alongside professional medical guidance to make informed lifestyle and healthcare decisions that support your long-term health and quality of life.
No lab visits or doctor appointments
Saliva test of cortisol (no blood needed)
World class CLIA-certified labs
Physician reviewed results
Fast, secure, and confidential reports
Free shipping
Qualifies for payment using HSA/FSA
Still wondering how do you test for cortisol awakening response?
Physician-Authorized Testing with Free Shipping: Every at-home cortisol test kit from RxHomeTest.com includes a physician's prescription and a detailed review of your results by one of our physicians at no additional cost. Shipping is FREE throughout the United States. We also offer free outbound shipping to Canadian addresses; however, customers in Canada are responsible for arranging return shipment of their samples to the laboratory.
Trusted, CLIA-Certified Laboratories: Your cortisol samples are analyzed by the same high-quality, CLIA-certified laboratories used by healthcare professionals. This ensures your samples are processed according to established laboratory quality standards, giving you confidence in the reliability of your results.
Comprehensive Cortisol and Adrenal Hormone Testing Options: RxHomeTest.com offers convenient, confidential, and reliable cortisol testing at highly competitive prices. Choose from several at-home saliva testing options, including an AM/PM Cortisol Test, a 24-Hour Cortisol Profile, an Adrenal Stress Test combining cortisol with DHEA or DHEA-S, and a Cortisol Awakening Response (CAR) Test. These options allow you to explore different aspects of cortisol production, daily hormone patterns, and stress-related hormonal regulation.
Convenient At-Home Testing Without a Doctor or Lab Visit: Order your cortisol awakening response saliva test kit online without scheduling a doctor's appointment or obtaining a separate prescription. Your order includes the required physician authorization, allowing you to collect samples conveniently at home. No laboratory appointments, travel, or time away from work are needed, saving you both time and money.
Simple, Non-Invasive Saliva Collection: Our cortisol testing kits use saliva samples analyzed through laboratory immunoassay methods, such as ELISA. Unlike traditional blood or serum cortisol tests, saliva testing requires no needles or blood draws. Simply collect your samples at the specified times using the instructions provided with your kit, making it an easy and comfortable way to assess your cortisol patterns.
