Cortisol, "Adrenal Fatigue" and What the Science Supports
What cortisol does, why "adrenal fatigue" is not a recognized diagnosis, which real adrenal conditions exist, and what research says about breathing, mindfulness and ashwagandha for cortisol.
Content last updated . This page has not been medically reviewed.
The short answer
Cortisol is a hormone your body needs. "Adrenal fatigue" is a popular label for tiredness and stress symptoms, but the Endocrine Society says no scientific proof supports it as a true medical condition. [1] Real adrenal diseases do exist, but they are diagnosed with blood tests and treated by doctors, and they are different from the "adrenal fatigue" idea. This page explains the difference. Evidence labels used: established recommendation, promising but limited, mixed, insufficient evidence.What cortisol is
Cortisol is made by the adrenal glands, two small organs that sit on top of each kidney. They also make aldosterone, adrenaline and noradrenaline. [2] NIDDK calls cortisol "sometimes called the stress hormone" and says it is essential for life. [3] When you feel anxious or scared, your body releases stress hormones such as adrenaline and cortisol, which can speed the heart and cause sweating. [4]So cortisol is not a "bad" hormone to be minimized. The goal is not to have as little as possible.
"Adrenal fatigue": the claim
According to the Endocrine Society, the idea says long-term stress overwhelms the adrenal glands so they cannot make enough hormone, which then causes symptoms such as tiredness, trouble sleeping or waking, salt and sugar cravings and needing caffeine to get through the day. [1]| Claim | What the sources found |
|---|---|
| It is a real medical condition | The Endocrine Society says no scientific proof exists. [1] A systematic review of 58 studies concluded there is no substantiation that "adrenal fatigue" is an actual medical condition and called it a myth. [5] |
| A saliva or blood test can detect it | The Endocrine Society says no test can detect it; tests offered are not based on good scientific studies. [1] |
| Special supplements treat it | The Endocrine Society says these supplements have not been tested for safety, and treatment for adrenal fatigue is not FDA-approved. [1] |
The review had limits too: it included a mix of study designs and noted conflicting findings in many studies. [5]
Why it is risky to accept the label
The symptoms listed are common and non-specific; they occur in many diseases and in a normal busy life. [1] The Endocrine Society warns that if you are told you have this condition, the real cause may not be found and treated. Tired, weak or depressed people may actually have adrenal insufficiency, depression, obstructive sleep apnea or another health problem. [1] See Why am I so tired?.There is a second risk. Taking adrenal hormone supplements you do not need can make the adrenal glands stop working, possibly leaving a person in danger of a life-threatening adrenal crisis. [1] Also, supplement labels do not guarantee what is in the bottle. [1] See Reading supplement labels and the adaptogen "adrenal support" claim check. For energy products, see Energy supplements and adrenal claims.
Real adrenal conditions
- Adrenal insufficiency (including Addison's disease): the adrenal glands do not make enough cortisol. Common symptoms are fatigue, muscle weakness, loss of appetite, weight loss and abdominal pain. It is diagnosed with blood tests and treated with medicines that replace the missing hormones. [3] Causes include autoimmune disease or suddenly stopping steroid medicines. [3]
- Cushing's syndrome: too much cortisol. It is rare, and the most common cause is taking high doses of steroid medicine for a long time. Features can include more body fat on the neck, upper back, chest and tummy, a red round face, easy bruising and stretch marks. [6]
Online, "cortisol belly" usually means belly fat blamed on stress. The only cortisol-related fat pattern described in the sources read here is the one in Cushing's syndrome above, which is a medical condition for a doctor to check. These sources do not show that everyday stress alone causes it. Do not suddenly stop steroid medicines on your own: that can itself cause adrenal insufficiency. [3]
Can you "lower cortisol"?
A few small areas of research touch cortisol. Measuring cortisol is a biomarker (a lab number), which is not the same as feeling better or having better health.| Approach | Finding | Evidence label |
|---|---|---|
| Slow, deep breathing | NCCIH says studies show it may modestly lower blood pressure and cortisol; a 2019 review of 3 studies (880 people) found preliminary evidence it may reduce stress. [7] | Promising but limited |
| Focused-attention meditation | A 2017 review of 8 studies found it reduced blood pressure and cortisol levels. [7] | Promising but limited |
| Ashwagandha | A 2024 meta-analysis of 9 randomized trials (558 people) found lower perceived stress, anxiety and serum cortisol than placebo; four trials reported mild to moderate side effects, and long-term safety is not known. [8] NCCIH says liver injury has been rare but reported. [9] | Promising but limited; see stress supplements compared |
| Everyday habits | Sleep, movement, healthy food and a regular routine will almost always make you feel better, whatever the diagnosis, according to the Endocrine Society. [1] | Established recommendation (general advice) |
Proper evidence not found in the sources read here showing that lowering cortisol with a supplement improves health outcomes.
When to get help
See a health care provider if you have ongoing fatigue, weakness, weight loss, easy bruising or a changed body shape, or if you have been told you have "adrenal fatigue" and want a second opinion. Tests for real adrenal problems are done by doctors. [3] If low mood or thoughts of suicide are present, in the US call or text 988 (free, 24/7); in a life-threatening situation call 911. [10] See Stress and anxiety safety.Frequently asked questions
Is adrenal fatigue real?
The Endocrine Society says no scientific proof supports it as a true medical condition, and a 58-study systematic review reached the same conclusion. [1][5]
Can a saliva test show adrenal fatigue?
The Endocrine Society says no test can detect it and tests offered are not supported by good studies. [1]
Does stress raise cortisol?
The body releases stress hormones including cortisol when you are anxious or scared. [4]
What is the difference between adrenal fatigue and adrenal insufficiency?
Adrenal insufficiency is a real, blood-test-diagnosed condition where the adrenal glands do not make enough cortisol. [3] "Adrenal fatigue" is not a recognized diagnosis. [1]
Does ashwagandha lower cortisol?
A 2024 meta-analysis of 9 trials found lower serum cortisol than placebo, but long-term safety is unknown and liver injury has been reported rarely. [8][9]
References
- Endocrine Society. Adrenal Fatigue (patient resource, last updated January 25, 2022). Read 2026-10-22.
- MedlinePlus. Adrenal Gland Disorders. Read 2026-10-22.
- National Institute of Diabetes and Digestive and Kidney Diseases. Adrenal Insufficiency & Addison's Disease. Read 2026-10-22.
- NHS. Stress. Read 2026-10-22.
- Adrenal fatigue does not exist: a systematic review. BMC Endocr Disord 2016. PMID 27557747. Read 2026-10-22.
- NHS. Cushing's syndrome. Read 2026-10-22.
- National Center for Complementary and Integrative Health. Stress. Read 2026-10-22.
- Effects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis. Explore (NY) 2024. PMID 39348746. Read 2026-10-22.
- National Center for Complementary and Integrative Health. Ashwagandha. Read 2026-10-22.
- 988 Suicide & Crisis Lifeline. 988 Lifeline home page. Read 2026-10-22.