We in the modern world, often lead frenetic and unbalanced lifestyles. Day to day life often involves continuous stress, not only from emotional stressors (such as marital, financial, and occupational) but also from physical stressors (such as sleep deprivation, caffeine consumption, pain and extreme exercise) all without adequate recovery.

Further physical stressors exist however and contribute to this overall load also, including the toxic and immune related onslaughts of petrochemical and metal toxins as well as infections (gut/yeast) and allergen exposures (diet/environmental).

Whilst many individuals are able to cope with these demands, the adrenal glands may, over time, start to have an impaired response to stressors, and reduced adrenal hormone output. The resulting adrenal insufficiency, may present with a constellation of symptoms from chronic fatigue to allergies, anxiety to infertility.

Subsequently, some key symptoms of Adrenal Dysfunction include morning or evening fatigue, allergies, increased infections, insomnia, poor recovery from exercise, apathy, chemical sensitivity, decreasing attention span, depressed mood, unstable blood sugar, low sex drive and that “burned out” feeling .

The Adrenal Gland and Cortisol Production

The Zona Fasiculata of the adrenal cortex secretes approximately 15-20 mg of Cortisol per day in a fluctuating pulsatile manner (known as the ‘Diurnal Rhythm’) that includes two primary peaks in the day (one around 8am in the morning and another somewhere around 3-4pm in the afternoon, before subsiding to negligible levels during sleep hours when Melatonin opposes its production (in those maintaining adequate sleep wake cycles).

Note: The Zona Fasiculata is stimulated to produce Cortisol in response to ALL the above mentioned stressors! (The Psychological, Emotional, Physical, Chemical, Toxic, Allergic and Infective).

Cortisol has a wide range of effects on the mind and body and all other hormone systems (especially the Thyroid and Reproductive). As part of the response to stress, it mobilises body resources to accommodate a demand to our system for ‘fight or flight’ responses, and in doing so it can suppress the production of other more ‘rest and digest’ (repair and maintenance) related hormones (including those of the immune system).

This not only temporarily shuts down ‘repair’ processes but also diverts crucial body resources elsewhere, for consumption at a rate often far higher than can be replenished until the demand has subsided. Therefore multiple and complex chronic disease and severe nutrient depletion are often the concomitant result of Adrenal depletion.

So Cortisol production can be considered to reflect our overall body reserve for accommodating stressors in all their forms, and since both high and low Cortisol levels are associated with multiple and often ambiguous symptoms, Cortisol testing is often required, to provide accurate insights into the severity and nature of this important body status/function and provides the holistically minded practitioner with the accurate measurement required to assess such cases objectively, as well as their ongoing response to treatment to replenish this reserve capacity.


Cortisol Testing

Cortisol testing can be carried out via Blood, Urine and Saliva.  Saliva testing often carries with it some limitations with regard to many other steroidal hormones, however Saliva testing for Cortisol production does provide one of the best clinical uses of this technology, assessing the bioavailable Cortisol levels by excluding the Cortisol-binding globulin (CBG)-bound hormone and is a well established method for the diagnosis of Cushing’s Disease (Hypercortisolism).

Importantly, the convenience of saliva collection also allows for the all important multiple (4x) sampling required over the course of a day (at morning, mid morning, mid afternoon and evening) to accurately assess the ‘Diurnal Rhythm’.

Blood spot testing on the other hand is another minimally-invasive testing method, that provides  a valuable first morning test to give an excellent snapshot of adrenal function (at its primary peak of the day) without the stress and inconvenience of more complex tests or blood draw collection.

Urine Cortisol readings (within a full 24 hour hormone excretion panel) provide an excellent overall snapshot of Cortisol production throughout the entire Diurnal Rhythm (yet will not necessarily reveal the peaks and troughs of its production during that period) and is most useful when assessing Cortisol’s relationship to all the other steroidal hormones (which are best assessed this way) and in those with disrupted/chaotic sleep cycles (such as shift workers and in those with severe insomnia).

Therefore, the Diurnal Cortisol Panel (4x), provides one of the most accurate and insightful methods for assessing Cortisol’s universally important status to mind and body health.

To your best,

Warren Sig


Warren Maginn, BHSc Nutr. Med. GradCert Hum. Nutr. – Practitioner and Educator

Warren Maginn holds a Bachelor Degree in Nutritional Medicine and is RN Labs’s National Technical Educator, carrying extensive technical knowledge in the field of Functional Medicine. Warren is also a Nutritional Medicine Practitioner and Lecturer for Endeavour College in Brisbane. He is passionate about assisting practitioners and students to gain greater technical insights from current functional medicine understanding and how to apply this knowledge in clinical practice.