New Evidence for Critics of Weight-Loss and Sports Supplements

The study found two banned stimulants and two previously unknown and little-studied substances in six weight-loss and sports supplements sold in the U.S. The researchers defined “banned” as “ingredients for which the U.S. Food and Drug Administration had taken enforcement action to remove from dietary supplements prior to August 2016 (when the samples were purchased).”

They tested six brands of supplements that listed ingredients on the label that appeared to be possible analogs of the stimulant DMAA. Among them: Cannibal Ferox AMPed, produced by a company called Chaos and Pain, and Simply Skinny Pollen, made by Bee Fit with Trish. The results were published earlier this month in the journal Clinical Toxicology.

The researchers discovered a form of DMAA found in some supplements, and another stimulant, DMBA, in others. Neither are legal supplement ingredients. This type of DMAA has been found to pose cardiovascular risks. Researchers haven’t determined the health risks of DMBA.

The study also uncovered a second analog of DMAA not previously found in supplements whose safety for humans is unknown. And it found octodrine, a stimulant formerly available in Europe as part of a treatment for low blood pressure and asthma. Regulators removed octodrine from European markets. Animal studies have suggested it has the potential for adverse cardiovascular effects.

Some of the products listed the names of similar types of compounds on the label, and some listed ambiguous or misleading ingredients, according to the study.

The four manufacturers of the supplements did not respond to calls and emails seeking comment.

“Many supplements sold as food are actually drugs,” says Pieter Cohen, an associate professor of medicine at Cambridge Health Alliance of Harvard Medical School and first author of the study. “This is clearly not permitted under the law.”

“The current regulatory framework does an extremely bad job of detecting dangerous supplements and then removing dangerous supplements,” he says.

Because supplements aren’t tightly regulated like prescription drugs, experts increasingly question their quality and safety. Supplement manufacturers don’t have to demonstrate safety or effectiveness to the FDA. Many supplements are easily available online and at mainstream retail stores.

Dr. Cohen has been studying the boundary between drugs and supplements for more than a decade. “These products are being used like a medication, but from a regulatory perspective, they’re being sold as food, and that results in a lot of confusion.”

Theresa Eisenman, a spokeswoman for the FDA, says the agency doesn’t comment on individual studies. But she says the organization has previously taken enforcement action against products with DMAA and DMBA.

The “FDA has been working to remove dietary supplements containing both of these ingredients from the marketplace, but it’s important to illustrate the challenges that we face,” she wrote in an email.

Companies and individuals who manufacture supplements are responsible for ensuring that their products are safe, she says. New dietary supplements can be introduced to the market without receiving approval or even notifying the FDA. The government requires premarket notification when a dietary supplement contains a new dietary ingredient. She says the FDA hasn’t received such a notification for the stimulants identified in the study.

Victor Navarro, medical chair of the department of digestive diseases and transplantation at Einstein Medical Center in Philadelphia, says 20% of the liver damage cases reported to the U.S. Drug-Induced Liver Injury Network are attributed to herbal and dietary supplements. The network—a federally-funded group of clinics creating a registry of patients for research purposes—started in 2003 and has seen about 1,500 patients.

Dr. Navarro recently presented data at the annual gathering of the American Association for the Study of Liver Diseases in Washington, D.C. Researchers examined the supplements their liver patients were taking.

They verified the labels of more than 200 supplements and, through a chemical analysis, found that in 50% of the cases, what was on the label didn’t match what was in the bottle. Eighty percent of bodybuilding and performance-enhancement supplements had labels that didn’t match their actual ingredients, while 72% of weight-loss products had the same issue.

“People take these supplements and they think that they’re safe because they’re natural, but some of them have the capacity to cause harm for people,” Dr. Navarro says. The worst-case scenario for these patients could be liver failure, he says.

Duffy MacKay, senior vice president of scientific and regulatory affairs for the Council for Responsible Nutrition, a Washington, D.C.-based trade group of dietary supplements and functional foods, says the products mentioned in the Clinical Toxicology study are outliers and don’t represent the majority of legitimate supplements.

The FDA has been working with other federal agencies to clamp down on another class of anabolic substances often found in supplements: SARMs (selective androgen receptor modulators), which are investigational drugs being developed to treat muscle weakness. The FDA issued a warning about SARMs in supplements last month, saying they are associated with potential increased risk of heart attack or stroke.

Write to Sumathi Reddy at Sumathi.Reddy@wsj.com

Corrections & Amplifications 
Retail sales of dietary supplements in the U.S. is expected to exceed $15 billion in sales in 2017. An earlier version of a chart in this article incorrectly stated that number as $15 million. (Nov. 20, 2017)