Cortisol is not the culprit
Cortisol is neither the villain behind every unwanted kilogram nor is it an imaginary concern.
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Cortisol is neither the villain behind every unwanted kilogram nor is it an imaginary concern.
CORTISOL plays a role in regulating blood pressure.
Photo courtesy of Unsplash/CDC
“Doc, I think I’m not losing weight because my cortisol level is high.”
This has become a familiar comment at my clinic, often accompanied by videos about “cortisol belly,” “cortisol face,” detox drinks, and supplements promising to reset the adrenal glands. The premise is tempting: if one hormone is to blame, lower it, and watch the weight disappear.
But human metabolism is rarely that simple.
Cortisol is a substance produced by the adrenal glands and is often called the “stress hormone.” While accurate, this description is incomplete. Cortisol rises appropriately in times of stress — illness, injury, tense situations. It also helps regulate blood glucose, blood pressure, inflammation and the metabolism of carbohydrates, protein and fat. It follows a daily rhythm — generally higher in the morning, a slight elevation by mid-afternoon, then lower at night. In short, we need cortisol to survive.
It is true that prolonged exposure to abnormally high cortisol can cause weight gain. This occurs in a condition called Cushing syndrome, a rare but serious endocrine disorder where a tumor can cause excessive cortisol levels. Patients may develop increasing fat around the abdomen, face, neck and upper back, while their arms and legs become thinner because of muscle loss. Other clues include wide purple stretch marks, easy bruising, muscle weakness in the legs, high blood pressure, diabetes, menstrual changes and weakening of the bones that can lead to fractures.
However, having abdominal fat or difficulty losing weight does not automatically mean that someone has Cushing syndrome. These symptoms are extremely common and can arise from many conditions. And it is not recommend to routinely test everyone with obesity for excess cortisol. Testing is advised when there are specific and progressive clinical features like the ones listed above that raise suspicion.
This distinction matters because social media often confuses ordinary stress with pathological cortisol excess.
Busting myths
Chronic stress can certainly influence weight. It may increase appetite, intensify cravings for calorie-dense food, disrupt sleep, reduce physical activity, and encourage emotional eating. Research also suggests associations between altered cortisol patterns and abdominal obesity, but the findings are complex and do not prove that cortisol alone causes the weight gain. Sometimes stress changes behavior; sometimes obesity alters hormonal patterns; and often both occur together.
In other words, stress may contribute to weight gain, but it does not place the body under an unbreakable hormonal spell. Cortisol does not suspend the basic biology of energy balance, nor does a stressful week automatically create a “cortisol belly.”
Another myth is that a single blood test can confirm Cushing syndrome and explain stubborn weight. Cortisol levels change throughout the day and can be affected by sleep, acute illness, exercise, alcohol, depression and even the stress of having blood drawn. A random serum cortisol level is, therefore, not recommended for diagnosing Cushing syndrome. When testing is truly indicated, accepted methods include late-night salivary cortisol, 24-hour urinary free cortisol, and an overnight dexamethasone suppression test – all of which should be interpreted by an endocrinologist. And even when a test indicates Cushing syndrome, a confirmatory test should be done.
We should also review medications. Prolonged exposure to glucocorticoids — such as prednisone, dexamethasone, or repeated steroid injections — is the most common cause of Cushing syndrome. Inhaled, topical and other steroid preparations can sometimes contribute, particularly in high doses or through drug interactions. These medicines should never be taken without a proper prescription. And patient who need to take steroids should not stop taking them suddenly without medical advice.
What about supplements that claim to “block cortisol?” There is no convincing evidence that over-the-counter cortisol blockers produce meaningful, lasting weight loss. Weight-loss supplements may contain poorly studied combinations, interact with medications, or even include undeclared, harmful ingredients. If it sounds too good to be true, it most probably is, and often costs a pretty penny.
Thoughtful assessment
Reducing stress remains worthwhile — not because it melts abdominal fat overnight, but because better sleep, regular exercise and relaxation make it easier to regulate appetite and sustain healthy habits. Evidence-based weight management still begins with an individualized eating plan, physical activity that includes resistance exercise, adequate sleep and attention to medications and medical conditions. When appropriate, prescription anti-obesity medication or metabolic surgery may also be considered as part of comprehensive care.
Cortisol is neither the villain behind every unwanted kilogram nor is it an imaginary concern. But true cortisol excess deserves careful investigation and treatment. For those struggling with weight, the answer is never a detox tea, an “adrenal reset,” or an expensive supplement.
It is a thoughtful assessment of the whole person — their biology, environment, habits, health, medications, sleep and stress. Hormones matter, but they do not tell the whole story.
