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This test uses a convenient salivary sample collection method to assess an individual’s 24 hour cyclic cortisol levels, including their morning cortisol surge or cortisol awakening response (CAR) as well as both their morning and afternoon dehydroepiandrosterone (DHEA) levels. A ratio between Cortisol/DHEA daily secretions is calculated to further reflect Hypothalamic-Pituitary-Adrenal (HPA) axis balance.


What Are The Adrenal Glands?

The adrenal glands are located at the top of the kidneys and produce hormones that help the body to control blood sugar, burn protein and fat, react to stressors and regulate blood pressure. They are made up of 2 distinct components, the adrenal cortex (outer part) which produces the hormones cortisol, aldosterone and DHEA and the adrenal medulla (inner part) which produces adrenaline and nor-adrenaline.


What Causes HPA Axis Dysfunction?

During acute stress, the hypothalamus stimulates the adrenal medulla to release adrenaline and nor-adrenaline, which serve to enable a fight or flight response. If the stressor persists after this initial reaction phase, a more prolonged stress response is initiated. This is achieved by increasing Adrenocorticotropic Hormone (ACTH) secretion from the pituitary gland, prompting the release of cortisol and DHEA from the adrenal cortex.


The rate of cortisol and DHEA secretion is regulated through the HPA axis negative feedback loop. A sustained demand for cortisol, in response to continued stress without adequate recovery, stimulates ongoing ACTH release by the pituitary gland. Over time, the HPA axis will adapt by downregulating ACTH production, and thus cortisol stimulation, in order to protect the tissues. If stressors continue, semi-permanent down-regulation occurs characterised by cortisol and DHEA levels below the reference range. At this stage the body will have difficulty meeting the demands of the day.


What Are The Symptoms Of HPA Axis Dysfunction?

  • Low energy
  • Salty food cravings
  • Brain fog
  • Poor sleep quality
  • Difficulty waking
  • Low libido
  • Reliance on caffeine
  • Weakened Immunity
  • Inability to handle stress
  • Central weight gain


Why Test For Cortisol And DHEA?

Optimally functioning adrenal glands are vital to survival, by enabling the body to balance energy expenditure with demand. In response to physiological or psychological stress, the adrenal glands should release appropriate levels of specific hormones, including adrenaline, cortisol and DHEA, to meet demand. Low secretion of adrenal hormones, due to downregulation of the HPA axis, can inhibit an individual’s ability to respond effectively to daily stressors.


If several of the symptoms listed above are highlighted, a HPA Axis and Stress Function test may help to identify whether low secretion of cortisol in response to HPA dysregulation is a contributory factor and lifestyle factors can be targeted and addressed as part of a recovery programme. Please note that where there is an imbalance with the HPA axis that thyroid hormone, DHEA and testosterone synthesis may also be disrupted.


How Does The Test Work?

5 saliva samples are taken at specific times throughout the day. Cortisol levels should fluctuate over a 24-hour period, with a spike upon waking and a steady decrease to their lowest concentration at night. Taking a single reading, or calculating a 24-hour average, is not sufficient.


The elevation of the morning spike and its subsequent reduction within the first hour of waking, CAR, is measured in the first 3 samples, reflecting both hormone status on waking and ability to respond to the events of the day ahead. 2 further samples are taken, 1 mid-afternoon the other in the evening. The 5 samples plot the secretory pattern of cortisol and DHEA over a 24-hour period and thus give a reflection of HPA axis and stress function.


Our test includes both a morning and afternoon DHEA measurement, in order establish the Cortisol/DHEA ratio. This ratio is considered to be a measure of anabolic vs catabolic activity, as DHEA acts as both an anabolic hormone and it may down-regulate, or ‘buffer’ the cellular effects of cortisol.


What Can Be Done To Support My Adrenal Glands?

If low cortisol levels are indicated at any specific point during the day or over the course of the day, with a DHEA concentration below the normative reference range, or if an elevated cortisol to DHEA ratio is observed, this would signify HPA axis dysfunction. At this stage it would be advisable to encourage necessary lifestyle and dietary modifications, such as improving sleep duration and quality, employing stress management techniques and encouraging mindfulness and mediation, and healthy exercise to support the HPA axis and address adrenal hormone output. Dietary interventions such as reducing sugar, caffeine, alcohol and processed food consumption, may be further supportive strategies, along with increasing nutrient dense foods high in specific adrenal-supporting nutrients such as vitamins B, particularly Vitamin B5, Vitamin C, zinc, magnesium and omega 3 (EPA/DHA). This will be discussed with your practitioner.



  • Cortisol
  • DHEA

HPA Axis and Stress Function Test

  • All ordered tests will be mediated by our Naturopath, Lekita Davies. Once test results have been returned to us, Lekita will call the client to deliver the results and discuss anything appropriate for the case. After the phone call, results will be emailed to the client alongside any suggestions. Please note that we cannot deliver results without a phone call.

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