The majority (75%) of weight loss supplements bought online as part of a study contained ingredients that could cause lethal heart rhythm disturbances, say U.S. researchers.
They tested 12 over-the-counter diet supplements and found eight contained at least one ingredient associated with life-threatening heart complications, such as ventricular arrhythmia and cardiac arrest.
While all of the products included a list of the ingredients, none came with a warning about the potential heart rhythm side effects.
Dietary supplements, including many weight-loss supplements, do not undergo the same regulatory scrutiny by the U.S. Food and Drug Administration as drugs do.
This study is the first to examine the potential heart risks of weight-loss supplements purchased online.
The researchers did not disclose brand names of the pills they tested. Instead, they offered a list of risky ingredients found in the pills that he said consumers should watch out for.
They even found one ingredient - a type of ephedra known as Ma Huang root - that has been banned by the FDA since 2004.
Other potentially dangerous ingredients included bitter orange, also known as Synephrine HCl and Citrus aurantium; green tea, also known as Camellia sinensis; buckwheat, guarana, Korean ginseng, licorice root and caffeine anhydrous.
Some of the substances, such as licorice root, can cause trouble on their own by lowering potassium levels, which could alter the heart's electrical system.
Others, such as green tea, are harmless taken in normal doses, but can amplify the effects of some of the other ingredients.
The bottom line: Be cautious and informed and do your research before taking a weight loss supplement.
All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.