Some manufacturers of weight-loss supplements allude to the possibility that their products block the cortisol in your body, a hormone associated with excess visceral fat. Synthetic cortisol is a prescription drug that doctors may recommend for specific medical conditions unrelated to obesity. Dietary supplements, on the other hand, don't need pre-market approval from the U.S. Food and Drug Administration before they're sold to consumers. You have no assurance that they're safe — or that they're effective.
Cortisol is known as the stress hormone. It's produced by the adrenal glands, which are located on either side of your kidneys, and it is necessary for normal blood pressure and metabolism. Cortisol is also released during periods of intense stress, when your "fight or flight" response is triggered, reports Health Services at Columbia. Once you calm down, your level of cortisol drops. However, if you're in a constant state of stress, cortisol may be released in excessive amounts, which can impair your immune system. High levels of cortisol also release fatty acids into your blood, which can cause clogged arteries. The Exercise Science Division at the University of New Mexico reports that excess cortisol may cause fatty deposits in the abdomen, resulting in visceral fat. Cortisol is also linked to an increased appetite and food cravings, particularly for sugary or fatty foods.
Cortisone or corticosteroids are used to treat asthma, psoriasis, lupus and some types of arthritis. They may be used in conjunction with other treatments for certain types of cancer, as well as after an organ transplant to reduce the recipient's risk of rejecting the new organ. However, manufacturers of natural cortisol supplements, or cortisol blockers, may suggest that they help you lose weight by decreasing the cortisol in your body that purportedly causes excess weight. In the past, supplement manufacturers have run afoul of federal regulatory agencies for making unsubstantiated and misleading claims about these supplements.
In 2004, the FDA and the Federal Trade Commission were alerted to the false, misleading and unsubstantiated claims being made by sellers of cortisol supplements who were alleging that their products blocked hormone production. Manufacturers of two cortisol-blocking supplements claimed that their products could help consumers lose a dramatic amount of weight per week — from four to 10 lbs. — specifically from the abdomen and thighs. Other claims associated with these supplements were that they curbed food cravings and emotional eating. One manufacturer claimed that its product was backed by 15 years of scientific research — a claim that the FTC determined was false. In 2007, the FTC reached a settlement with the manufacturers of two such supplements. The commission accepted refund requests from consumers who purchased the products between August 1, 2003, and May 31, 2006.
MayoClinic.com reports that there's no conclusive evidence to support the claim that cortisol causes excess fat. It goes on to note that the only way to lose weight is to reduce the number of calories you eat and get more physical exercise. Dietary supplements aren't necessarily safe for everyone. The FDA indicates that these may not be appropriate for pregnant and nursing women, or for people with chronic conditions such as diabetes, heart disease and hypertension. Dietary supplements may not mix well with other medications and supplements, even those that contain natural ingredients. Always talk to your treating physician before taking a dietary supplement of any kind to address weight gain, obesity or other health concerns.