The Cortisol Weight-Loss Controversy

Table of Contents
View All
Table of Contents

Cortisol is a key hormone in metabolism and your body's response to stress, but its relationship to weight gain and weight loss is complicated.

Some evidence suggests that increased stress, which can raise cortisol, can lead to overeating and weight gain in some people. People with serious metabolic conditions that involve excessive cortisol production, such as Cushing syndrome, have an unhealthy increase in abdominal fat.

A metabolic-associated increase in abdominal fat is also seen in people who develop insulin resistance, which can lead to metabolic syndrome and type 2 diabetes.

Marketers of supplements that claimed to block cortisol to produce rapid weight loss ran afoul of the U.S. Food and Drug Administration. Targeting cortisol is simplistic, and if products like these had a significant action they would likely have serious side effects.

Understanding the role of cortisol in the body can help you weigh the validity of the possible benefits of such products, as well as take action that may improve your metabolic health.

Female leg stepping on weigh scales. Healthy lifestyle, food and sport concept.
spukkato / Getty Images

What Cortisol Does

Cortisol is a hormone produced by the adrenal gland when the body is under stress. Your hypothalamus, via the pituitary gland, directs the adrenal glands to secrete both cortisol and adrenaline.

Cortisol is released as part of your daily hormonal cycle, but both it and adrenaline can also be released in reaction to perceived stress—both physical and emotional—as part of the fight-or-flight response essential for survival.

Adrenaline makes you energetic and alert and increases metabolism. It also helps fat cells release energy.

Cortisol helps your body become even more effective at producing glucose from proteins, and is designed to help quickly increase the body’s energy in times of stress.

It’s not the classic fight-or-flight stress that’s thought to cause weight problems, because in those situations, a stressful event is quickly resolved. The cortisol released is absorbed into your system, aided by the increased circulation provided by a pounding heart.

The concern comes when there is excess cortisol production and levels remain high, as occurs with a constant state of stress.

Effects of Excess Cortisol

Excess cortisol stimulates glucose production. This excess glucose then typically is converted into fat, which gets stored.

A number of research studies show that fat cells can, in the presence of too much adrenaline, become resistant to the effects of adrenaline.

Eventually, the fat cells become unresponsive to adrenal stimulation to release fat, but through the presence of high cortisol, they’re more responsive to fat storage. At the same time, high levels of circulating cortisol increase the risk of obesity and increased fat storage.

Of particular concern is abdominal weight gain—one of the most dangerous types of obesity, and one that contributes to an increased risk of metabolic syndrome, diabetes, and heart disease.

Some studies have found a difference in individuals who respond to stress-induced higher cortisol levels by increasing the amount of food they eat. Some are high responders, while others have no such response. However, the results from different studies have found a variety of results.

Insulin Resistance and Abdominal Fat

Sustained increases in cortisol, such as is seen in Cushing syndrome or people taking glucocorticoid medications, can result in insulin resistance. Other causes of insulin resistance include genetics, obesity, and lack of physical activity.

In insulin resistance, the brain and some of the body’s cells fail to react to the presence of insulin in the bloodstream and take in glucose produced by food digestion. The glucose continues to circulate in the bloodstream.

After a period of time, the overworked pancreas begins to tire and may lose its ability to produce enough insulin, leading to type 2 diabetes. Insulin resistance is, in fact, sometimes called pre-diabetes.

The fat cells in your abdomen are particularly sensitive to high insulin and are very effective at storing energy—far more so that fat cells you’d find in other areas such as the lower body (i.e. hips, rear end, thighs).

Metabolic syndrome is diagnosed once insulin resistance results in abdominal obesity, low HDL cholesterol levels, high blood pressure, and high fasting glucose levels.

Metabolic syndrome puts you at far greater risk of heart disease and stroke. People with metabolic syndrome may progress to type 2 diabetes.

Reversing Insulin Resistance

Insulin resistance and type 2 diabetes are reversible conditions.

Exercise helps cells respond more effectively to insulin—which then helps reduce the excess glucose in the bloodstream before it is stored as fat.

Fewer simple carbohydrates reduce the overall circulating blood glucose levels. And avoiding overeating prevents excess calories from all sources from being released into the bloodstream as glucose.

The less glucose, the less insulin. When insulin levels are low, the body turns to fat reserves for energy and starts to break down large fat molecules into fatty acids for easy energy production.

Prescription drugs such as Glucophage (metformin) can help insulin sensitivity.

Reducing Cortisol

As cortisol has a role in developing abdominal obesity, one might follow that line of thinking and conclude that they should take steps to block it to prevent belly fat or encourage weight loss. It's not that simple.

While this is sometimes done when medically necessary, reducing the amount of cortisol circulating in the body with medication is done slowly and with great care. This process is known as tapering.

You need cortisol to perform essential metabolic functions, and abruptly blocking cortisol in an attempt at weight management would have unpleasant or dangerous side effects.

For example, if you are prescribed a corticosteroid drug such as prednisone (which raises cortisol), you will be instructed to slowly reduce the amount taken over a number of days rather than simply stopping the drug.

This is because the feedback loop of the hypothalamic-pituitary-adrenal axis reacts to high cortisol levels by shutting down your body's own production of cortisol, which will take time to ramp up again to provide enough for your necessary metabolism.

An abrupt decrease can result in symptoms such as fatigue, fever, muscle and joint pain, and psychiatric symptoms.

When Cushing syndrome is caused by a hormone-producing tumor, a cortisol-reducing drug may be given before the tumor is removed. However, these drugs need to be carefully monitored as sudden fluctuations in cortisol can produce significant side effects.

The drugs used to reduce cortisol in Cushing syndrome can cause hyperglycemia, diabetes, and dangerously low potassium levels.

Supplement Claims

Supplements that claimed to reduce the effects of cortisol in order to promote weight loss were heavily advertised in the early 2000s.

One such, CortiSlim, was subject to a Federal Trade Commission (FTC) action over such claims. As a result, the manufacturer changed its advertising and eventually went out of business.

The U.S. Food and Drug Administration (FDA) also notified the manufacturer that their claims that the product controlled cortisol in a healthy range and helped lose weight were unsubstantiated.

In other words, it didn't work. If it did work as claimed, it would need to be regulated as a drug.

Other supplements such as phosphatidylserine are claimed by some to reduce the brain's reaction to stress, thus reducing cortisol and assisting in weight loss.

Weight loss products citing a cortisol-blocking effect may come and go in popularity. They are classified as dietary supplements, which means they are not required to undergo testing or research to back up these claims.

Non-Supplement Remedies

Rather than a supplement, the Centers for Disease Control and Prevention (CDC) and other health authorities recommend behavioral changes that will reduce your stress level and help reverse insulin resistance.

These include:

  • Focus on becoming stress-resistant. One of the best things to reduce stress and improve insulin sensitivity, for example, is getting regular exercise, even a daily brisk walk.
  • Practice stress-reduction techniques such as yoga, tai chi, meditation, breathing exercises, anger management therapy, therapeutic massage, listening to calming music, or others. These sort of approaches can help reduce your body’s physiological response to daily stressors.
  • Get enough sleep. Chronic sleep deprivation increases stress, reduces the immune system, and makes it more likely that you’ll be overweight.
Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Herhaus B, Ullmann E, Chrousos G, Petrowski K. High/low cortisol reactivity and food intake in people with obesity and healthy weightTransl Psychiatry. 2020;10(1):40. doi:10.1038/s41398-020-0729-6

  2. Federal Trade Commission. Notice of potential illegal marketing of products that claim to cause weight loss, reduce the risk of disease, or produce other health benefits by affecting the stress-related hormone cortisol: immediate action required. October 1, 2004. 

  3. Thau L, Sharma S. Physiology, cortisol. StatPearls. Updated 2019.

  4. Kargi AY, Iacobellis G. Adipose tissue and adrenal glands: novel pathophysiological mechanisms and clinical applications. Int J Endocrinol. 2014;2014:614074. doi:10.1155/2014/614074

  5. Kelsall A, Iqbal A, Newell-Price J. Adrenal incidentaloma: cardiovascular and metabolic effects of mild cortisol excessGland Surg. 2020;9(1):94–104. doi:10.21037/gs.2019.11.19

  6. Geer EB, Islam J, Buettner C. Mechanisms of glucocorticoid-induced insulin resistance: Focus on adipose tissue function and lipid metabolismEndocrinol Metab Clin North Am. 2014;43(1):75–102. doi:10.1016/j.ecl.2013.10.005

  7. Centers for Disease Control and Prevention. The insulin resistance–diabetes connection. Updated August 12, 2019.

  8. International Diabetes Federation. IDF worldwide definition of the metabolic syndrome.

  9. Adeva-andany MM, Rañal-muíño E, Fernández-fernández C, Pazos-garcía C, Vila-altesor M. Metabolic effects of metformin in humans. Curr Diabetes Rev. 2019;15(4):328-339. doi:10.2174/1573399814666181009125348

  10. Hospital for Special Surgery. Steroid side effects: How to reduce drug side effects of corticosteroids. Updated October 31, 2019.

  11. Oregon Health Sciences University Brain Institute. Cushing disease/Cushing syndrome.

  12. U.S. Food and Drug Administration. FDA Warning Letter to CortiSlim. August 19, 2004.

  13. Federal Trade Commission. Consumer Information. Dietary supplements. Updated November 2011.