What Is Cortisol and How to Lower It
Articles
Stress is a natural part of life, and cortisol is one of the key hormones that help the body cope with it. In the short term, it acts as a "lifesaver" and its effect is essential: it mobilises energy, supports alertness and allows a quick response to stress. However, when stress is chronic and cortisol levels stay raised for a long time, this protective mechanism can turn into a factor that gradually depletes the body and disrupts overall health.
What will you learn from this article?
- What is cortisol and where is it produced
- What are the functions of cortisol in the body
- Long-term stress and adrenal exhaustion
- How adrenal exhaustion manifests
- How cortisol can be measured in the body
- How to support adrenal function and lower cortisol
- Adrenal cocktail
- Key takeaways
What is cortisol and where is it produced
Cortisol is a steroid hormone that belongs to the glucocorticoid group and is produced in the adrenal cortex. Cortisol production is regulated by a system known as the HPA (hypothalamus–pituitary–adrenal) axis, which maintains hormonal balance and enables the body to respond to internal and external stimuli. Cortisol is not just a "stress hormone". Although it is often associated with stress, its functions go far beyond the stress response and affect many physiological processes needed to keep the body in balance.
What are the functions of cortisol in the body
Cortisol affects metabolism, the immune system, sleep quality and mental resilience. Its proper regulation therefore matters not only for managing stress, but for overall health, recovery and long-term vitality. Understanding how cortisol works in the body and what affects its levels is the first step towards consciously building resilience to stress and taking better care of your health, including the prevention of lifestyle diseases.
Metabolism and energy availability
In metabolic processes, cortisol is key to managing energy. During a stress response, it releases sugar into the blood to provide the energy needed and prepares the body for the "fight or flight" response. However, if the body is in long-term chronic stress, this originally protective response can lead to long-term raised blood sugar and the risks that come with it.
Immune system and inflammation
Cortisol also strongly influences the immune and inflammatory response. In the short term, it acts as an anti-inflammatory and dampens immune reactions, which is important during acute stress. With chronically raised levels, however, the immune system becomes less sensitive and its function may be weakened, which contributes to a higher susceptibility to infections and inflammation.
Stress response
Cortisol is one of the main regulators of the body's response to stress. It is activated by physical stress (e.g. physical strain, injury or the need to defend against a threat) or psychological stress (e.g. anxiety, pressure). In the acute phase, it helps rapidly mobilise energy, increases alertness and supports concentration. This hormone therefore enables the body to respond effectively to challenges and threats.
Blood pressure and cardiovascular system
Cortisol also takes part in regulating blood pressure by modulating the natural tension of blood vessels, sodium and water balance, and interaction with other hormones. Higher cortisol levels are linked to a greater susceptibility to hypertension, while low levels may contribute to low blood pressure and heart weakness.
Sleep and circadian rhythm
Cortisol plays a key role in the daily rhythm and circadian regulation. When the body works healthily, its levels are typically highest in the morning, to help wake the body up and prepare it for daily activity. In the evening and at night, they should fall to support falling asleep and deep sleep, and not block the release of melatonin, the sleep hormone.
Disruption of this rhythm (e.g. due to chronic stress or a poor sleep routine) leads to poorer sleep quality, fatigue and slower recovery. In the long term, persistently raised cortisol can lead to so-called "adrenal exhaustion" of the glands that produce it, and to fatigue syndrome.
Nervous system and mental resilience
Cortisol also influences the nervous system and brain functions, including mood regulation, motivation and cognitive processes. Appropriate cortisol levels help maintain the ability to adapt to stress, while long-term dysregulation can contribute to anxiety, depressive symptoms and reduced mental resilience.
Long-term stress and adrenal exhaustion
The term "adrenal exhaustion" (adrenal fatigue) is used in holistic medicine to describe a state in which chronic stress depletes the adrenal glands and reduces their ability to produce hormones, especially cortisol. Long-term emotional or physical strain can lead to overall fatigue, reduced resistance to stress, sleep disorders and energy crashes.
The gradual decline in adrenal function happens in several stages, which are linked to a functional imbalance of the HPA axis (hypothalamus–pituitary–adrenal) and to the body's adaptation to persistent stress factors.
Chronic stress and activation of the stress axis
Long-term psychological, emotional or physical stress activates the sympathetic nervous system and the HPA axis, which controls cortisol production. At first, cortisol rises as an adaptive mechanism that helps mobilise energy and cope with strain.
If stress persists, the regulation of the HPA axis can be disrupted. Cortisol is then released irregularly instead of in its natural rhythm, which reduces the body's ability to respond flexibly to stress and maintain its energy balance.
Reduced adaptive capacity of the body
During long-term strain, the adrenal glands stay in constant alert mode, which can lead to exhaustion and a reduced ability to secrete other hormones, fatigue, lower energy, poorer recovery and the symptoms known as adrenal fatigue.
Impact of lifestyle and environment
This condition can be further worsened by factors such as lack of sleep, irregular eating, a high intake of sugar and caffeine, and a lack of key nutrients.
How adrenal exhaustion manifests
Chronic fatigue and reduced energy:
- feeling exhausted even after enough sleep
- typical morning fatigue and "only getting going by late morning"
- reduced physical and mental endurance
Reduced stress tolerance:
- exaggerated reactions to common stressors
- feeling overwhelmed, inner tension
- inability to calm down quickly after stress
Sleep disorders:
- trouble falling asleep or frequent waking at night
- feeling "tired but wired"
- poor-quality, unrefreshing sleep
Psychological symptoms:
- irritability, mood swings
- anxiety, reduced mental resilience
- poorer concentration, "brain fog"
Energy fluctuations during the day:
- marked energy dips in the afternoon
- needing caffeine or sweets for a "boost"
- short-term improvement after stimulants, followed by a slump
Hormonal and metabolic signals:
- cravings for sweet or salty foods
- unstable blood sugar levels
- poorer recovery after exertion
Weakened immunity:
- more frequent colds
- slower recovery
- poorer response to infections
How cortisol can be measured in the body
Blood test from serum:
What it measures: the current cortisol level at a given moment. How it is done: a blood sample, usually in the morning (between 7 and 9 a.m.).
Saliva (salivary cortisol):
What it measures: free (biologically active) cortisol. How it is done: saliva samples taken several times during the day.
DUTCH test (Dried Urine Test for Comprehensive Hormones):
What it measures: not only free cortisol, but also its metabolites (cortisone), and it shows the daily curve.
Urine (24-hour collection):
What it measures: the total amount of cortisol excreted over 24 hours.
Cortisol levels from hair:
What it measures: long-term cortisol exposure (weeks to months).
How to support adrenal function and lower cortisol
Supporting adrenal function mainly means normalising the body's stress response and reducing the long-term load on the HPA axis. Meditation and other anti-stress techniques can help, as can supplementing specific nutrients such as vitamin C, which contributes to the normal function of the immune system, ideally in a natural form such as acerola. Magnesium bisglycinate contributes to the normal functioning of the nervous system and to normal psychological function, and from the B vitamin complex, vitamin B5 contributes to normal mental performance and vitamin B6 to the normal functioning of the nervous system. It is also worth making sure your vitamin D levels are adequate, ideally in the range of 100–150 nmol/l of serum 25(OH) vitamin D. Want to know what else helps lower high cortisol? Read our article Chronic stress and its impact on weight loss, sleep, and immunity.
Adrenal cocktail
An adrenal cocktail is a simple drink used mainly in functional medicine as a supportive tool for regulating the stress response and supporting the adrenal glands. It combines nutrients that the adrenals use up quickly during stress, so drinking it can help support their recovery.
Mix all the ingredients in water and drink. We recommend having it in the morning before breakfast.
Key takeaways
Cortisol is essential for the body: it helps manage stress and regulates energy metabolism, the immune system, blood pressure and the sleep rhythm. The problem is not its production, but a long-term imbalance.
Chronic stress disrupts the natural rhythm of cortisol: long-term psychological and physical strain can disturb its natural daily fluctuation and weaken the body's overall resilience.
Long-term strain can exhaust the adaptive capacity of the HPA axis: with persistent stress, the hypothalamus–pituitary–adrenal axis that controls cortisol production can become functionally dysregulated.
Common symptoms include fatigue and poorer stress management: typical signs are chronic fatigue, energy fluctuations, sleep disorders, lower stress resistance and more frequent infections.
Salivary tests capture the daily cortisol rhythm well: saliva samples taken at several points during the day give valuable information about cortisol's natural fluctuation and the body's response to stress.
An adrenal cocktail can support the body under increased strain: it provides vitamin C, sodium, potassium and other nutrients that are used up faster during long-term stress.
The goal is not to remove stress, but to adapt to it better: long-term balance is supported by good sleep, a balanced diet, regular exercise, enough recovery and the body's ability to adapt effectively to strain.
Sources:
[1] Cleveland Clinic. Cortisol: What It Is, Function, Symptoms & Levels. Updated February 17, 2025. https://my.clevelandclinic.org/health/articles/22187-cortisol
[2] Kaur J, Gandhi J, Sharma S. Physiology, Cortisol. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. Updated December 1, 2025. https://www.ncbi.nlm.nih.gov/books/NBK538239/
[3] Khodarahmi F. Adrenal Fatigue. Naturopathic Currents. Published September 2, 2015. https://naturopathiccurrents.com/en/2015/09/02/adrenal-fatigue/
