The Food and Drug Administration and the Federal Trade Commission issued warning letters today to seven companies that market over-the-counter weight loss products containing the hormone HCG, calling for these companies to stop selling and marketing these unapproved drugs.
Human chorionic gonadotrpin (HCG), otherwise known as a fertility hormone, is produced in women's placentas and is also found in pregnant women's urine. The hormone is FDA-approved only as a prescription injection drug to treat some cases of infertility and for select male hormone imbalances.
Some studies suggest that HCG can also absorb excessive fat tissue. Many companies also claim the hormone can curb appetite and speed metabolism.
HCG products sold online or in stores are not approved for weight loss. Still, so-called homeopathic versions of the hormone -- found as oral drops, sprays, and pellets -- are marketed by many companies as a weight loss supplement.
"Almost more than any other [market], the weight loss industry is fad driven," Richard Cleland, assistant director of the division of advertising practices at the Federal Trade Commission said today. "Also, unfortunately it is fraud driven."
It's unclear how much HCG is contained in the homeopathic products -- some suggest only trace amounts -- or whether the products truly contain HCG at all, even if labeled as such, said Elizabeth Miller, acting director of the Division of Non Prescription Products and Health Fraud at the FDA.
"Whether they contain it or not, they are illegal and unapproved drugs," Miller said.
Advertisements claim dramatic weight loss results of the HCG Diet, asserting that the diet program, which combines a 500-calorie diet while taking an HCG product, can produce fast results.
But there are no studies that show taking any product containing HCG as part of a low calorie diet has additional weight loss benefits, Miller said.
Women need to consume on average 1600 to 2400 calories a day and men need to consume 2000 to 3000 calories a day to maintain a healthy weight.
The FDA says a very low calorie diet can cause gall stone formation, electrolyte imbalances, and even heart arrhythmia, regardless of whether the hormone is also taken.
Companies that have been issued warning letters include Nutri-Fusion Systems LLC; Natural Medical Supply; HCG Platinum, LLC; theorginalhcgdrops.com; HCG Diet Direct, LLC; and Hcg-miracleweightloss.com.
Gary Arbuckle, co-founder of theorginalhcgdrops.com said even though the company solely sells HCG drops, it has no plans to shut down.
"We're looking at making some changes that [the letter] calls attention to," said Arbuckle, whose company is based out of Boise, Idaho. "Obviously our mission to help people with weight loss will be different. It's not going to end."
Arbuckle said he stands by his program because he says he is a testament to the weight loss success. Photos shown on his site indicate dramatic weight loss. And the testimonial he wrote on the company's website states he lost 36 pounds in 40 days.
But Arbuckle says that after being issued the FDA warning letter, he can't quite say that HCG was the source of his weight loss success.
"The program worked for me. Whether it was this or was that, I'm not sure," he said. "The program worked for me. I guess that's the safe way of stating the program."
Arbuckle declined to say how much HCG is contained in the drops and what changes will be made to the drops.
Calls made by ABC News to the other companies that were issued warning letters were not immediately returned.
It's not clear how many people are on the diet or buy these products, but Miller and Cleland said heavy marketing for these regimens on the Internet indicates there's a large consumer market out there.
Unlike companies that market homeopathic forms of HCG, some physicians like Dr. Sherri Emma, a weight loss physician based in Brick, N.J., uses the pharmaceutical grade HCG injection off-label for her weight loss patients.
Although studies show that people don't lose any additional amount of weight by adding HCG injections to their low calorie diet than with the low calorie diet alone, Emma said the difference is in how the weight is lost.
"HCG spares the muscle tissue but gets rid of the fat," said Emma, who treats about 100 patients a week with the diet program.
Emma said she's pleased about the joint agency's crackdown on homeopathic versions of HCG. Oral consumption of only trace amounts of HCG does not absorb into the body and does not work the same way as injections, she said.
In fact, HCG, a protein, is broken down as food when taken by mouth. That digestion process inactivates the hormone and therefore has no effect on the body, according to The Endocrine Society.
"I understand that this diet is becoming very popular, so I feel a sense of responsibility that people are educated and not doing things on their own," said Emma.
Still, the FDA said that regardless of the homeopathic labeling of HCG products, HCG is not an appropriate treatment for weight loss. Side effects of injection HCG include blood clots, decreased sperm production, and potential long-term risk of breast cancer in women.
About 8 million people a year fall victim to consumer fraud on the Internet, Cleland said.
Companies that have been issued a warning letter have 15 days to respond to the FDA and the FTC with steps they have taken to correct their violation or, according to the FDA website, the firms, "may face enforcement action, possible legal penalties, or criminal prosecution."