TUESDAY, Dec. 6 (HealthDay News) -- U.S. officials on Tuesday said that they are taking action to remove controversial, unapproved and illegally labeled HCG weight loss products from the market.

HCG stands for human chorionic gonadotropin, a hormone made by the human placenta and found in the urine of pregnant women. The products are typically given in conjunction with an extremely low-calorie diet -- as low as 500 calories per day -- which has some experts worried about possible health effects.

According to the U.S. Food and Drug Administration, companies marketing over-the-counter HCG weight loss products labeled as "homeopathic" were sent warning letters on Tuesday by the FDA and the U.S. Federal Trade Commission. The letters cautioned that the companies are violating federal law by selling the unapproved drugs, and by making unsupported claims for their products.

HCG is approved in the United States as an injectable drug for treating some cases of female infertility and other medical conditions, but is not approved as a weight loss aid.

The FDA said that HCG weight loss products are sold online and in stores as oral drops, pellets and sprays, despite no proof as to either their effectiveness or safety.

Visitors to the website for one maker included in the FDA action, The Original HCG Drops, are told they can "lose 20-30 pounds in 30-40 days," as they take the product. The company also claims that HCG "tells the body to release abnormal fat" and "hold on to lean muscle. All this is designed to establish a new body weight and reset your metabolism."

The FDA is especially concerned, however, because labeling on homeopathic HCG weight loss products typically advises consumers to take the products in conjunction with a very low calorie diet. However, there is no substantial evidence that the HCG products help people lose weight, the agency said, and people on these types of severely restricted diets put themselves at heightened risk for problems such as gallstones, electrolyte imbalances and heartbeat disorders called arrhythmias.

"These products are marketed over-the-counter on websites and in some retail stores, and can be found in the form of oral drops, pellets and sprays," Elizabeth Miller, acting director of the Division of Non-Prescription Products and Health Fraud in the FDA's Office of Compliance, Center for Drug Evaluation and Research, said during a late morning news conference.

"Currently there are no FDA-approved HCG drug products for weight-loss," she said. "FDA thinks it is important for consumers to understand that these products are potentially dangerous if taken as directed."

Neither the FDA nor the Federal Trade Commission (FTC) know how many people use these products.

"The indication is that they are being heavily marketed on the Internet and that suggests to us that there are purchasers out there," Richard Cleland, assistant director of the FTC'S Division of Advertising Practices, said during the news conference. "A survey we conducted several years ago of all types of diet products indicated that there were almost 5 million Americans a year that are victimized by weight-loss fraud."

One expert agreed with the FDA's move.

"The HCG diet is a typical fad diet that preys on people's desperation for fast weight loss," said Samantha Heller, a dietitian, nutritionist, exercise physiologist and clinical nutrition coordinator at the Center for Cancer Care at Griffin Hospital in Derby, Conn. "Not only is it dangerous for people to consume only 500 calories a day over time but the safety and efficacy of taking HCG for weight loss has not been established. A near starvation diet can result in emotional, psychological and physiological damage."

The companies have 15 days to notify the FDA of measures they've taken to correct the violations outlined in the warning letters. If they fail to respond, the companies may face legal action, including seizure and injunction, or criminal prosecution, the FDA said.

"Deceptive advertising about weight loss products is one of the most prevalent types of fraud," David Vladeck, director of the FTC's Bureau of Consumer Protection, said in the statement. "Any advertiser who makes health claims about a product is required by federal law to back them up with competent and reliable scientific evidence, so consumers have the accurate information they need to make good decisions."

Companies receiving warning letters are: HCG Platinum, LLC makers of "HCG Platinum," "HCG Platinum X-30," and "HCG Platinum X-14"; HCG Diet Direct, LLC, makers of HCG Diet Homeopathic Drops; theoriginalhcgdrops.com and resetthebody.com, marketers of "Homeopathic Original HCG" and "Homeopathic HCG"; Natural Medical Supply, whose products include "Alcohol Free hCG Weight Loss Formula," "hCG Diet Pellets Weight Loss Formula," and "hCG Diet Drops Weight Loss Formula"; Nutri Fusion Systems LLC, makers of "HCG Fusion 30" and "HCG Fusion 43"; and hcg-miracleweightloss.com, marketers of "HCG Extra Weight Loss Homeopathic Drops."

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases outlines how to choose a safe and effective weight loss program.