Cortisol Awakening Response

The Cortisol Awakening Response (CAR) is a transient, immediate rise in cortisol upon awakening and is distinct from the diurnal rhythm. CAR reflects a person's ability to cope with anticipated challenges and their perception of control around chronic stress. CAR measurement provides insight into HPA axis resiliency.

The CAR Profile requires three awakening salivary samples to evaluate CAR with one evening cortisol sample, which has distinct clinical implications. This profile is available as an alternative or an add-on to our Adrenal Stress Profile (ASP) and our Comprehensive Adrenal Stress Profile.

Waking 30min
CAR Add on Add on Add on
ASP (END01) Add on Add on Add on
Comp ASP (END02) Add on Add on

Additionally, CAR and ASP have the option of adding secretory IgA (sIgA).

To add flexibility in testing, each collection pack has the option to add CAR or ASP tests to convert the four-point test to a six-point test. The sample collection pack will have all required tubes so you do not need to order add-ons in advance.

Daily hassles, chronic pain, blood sugar dysregulation, work stressors, and poor relationship quality can alter the HPA axis. Imbalances in adrenal hormones can have a wide range of negative consequences that can adversely impact a patient's overall quality of life. The symptoms of HPA axis dysfunction can be vague, and are highly variable, but may include: fatigue, insomnia, weight gain, depression, GI complaints, and chronic pain. HPA axis dysfunction is associated with many conditions including:

  • hypertension
  • cardiovascular disease
  • gastrointestinal and immune dysregulation
  • diabetes and metabolic syndrome
  • depression
  • chronic fatigue
  • persistent pain
  • neurodegenerative disease and cognitive decline

Adrenal Stress Profile testing can reveal these HPA axis imbalances and provide direction for clinical intervention with targeted therapeutic treatments, such as nutrient support and/or adaptogens, stress management, behavioral modification, and lifestyle interventions.


  • Tsigos C, Chrousos GP. Hypothalamic-pituitary-adrenal axis, neuroendocrine factors and stress. J Psychosom Res. 2002;53(4):865-871.
  • Fries E, Dettenborn L, Kirschbaum C. The cortisol awakening response (CAR): facts and future directions. IntJPsychophysiol. 2009;72(1):67-73.
  • Clow A, Hucklebridge F, Stalder T, Evans P, Thorn L. The cortisol awakening response: more than a measure of HPA axis function. NeurosciBiobehavRev. 2010;35(1):97-103.
  • Hackett RA, Kivimäki M, Kumari M, Steptoe A. Diurnal Cortisol Patterns, Future Diabetes, and Impaired Glucose Metabolism in the Whitehall II Cohort Study. J Clin Endocr Metab. 2016;101(2):619-625.
  • Hammer F, Deutschbein T, Marx A, et al. High evening salivary cortisol is an independent predictor of increased mortality risk in patients with systolic heart failure. Inter J Cardiol. 2016;203:69-73.
Analyte List
Specimen Requirements
4 X plain saliva samples (collected over 24 hours).