Durbin, Blumenthal Press FDA to Investigate Amp Stimulant in Dietary Supplement

WASHINGTON—Sens. Dick Durbin and Richard Blumenthal on Wednesday pressed FDA to inspect dietary supplements containing a stimulant similar to one that has been associated with more than 100 illnesses including six deaths.

Researchers have found a stimulant known as 1,3-Dimethylbutylamine (DMBA) in 12 of 14 supplements that were marketed to boost athletic performance, improve brain function and increase weight loss, Durbin and Blumenthal said. The stimulant was found to be similar to DMAA, the senators said, a substance that FDA deems illegal and has been associated with dozens of adverse effects from deaths to heart attacks, seizures and psychiatric disorders. The ingredient is marketed as Amp or Amp Citrate, according to the Council for Responsible Nutrition (CRN), a trade organization representing the dietary supplement industry.

“The FDA has yet to take any effective action against companies manufacturing these products despite indications that the chemical may be mass-produced, has not been safety tested, and may be deceptively labeled," Durbin (D-Illinois) and Blumenthal (D-Connecticut) wrote in the letter. “FDA should investigate dietary supplements containing DMBA and other designer stimulants and take swift, appropriate regulatory action to immediately warn consumers against tainted products."

The research, published in the journal, Drug Testing and Analysis, recommended manufacturers recall supplements containing DMBA. The stimulant was found to be contained in 12 supplements that were sold by U.S. distributors, with dosages ranging from 13 to 120mg per serving, said the researchers from Harvard Medical School, NSF International and Netherlands-based National Institute for Public Health and the Environment.

"The FDA is aware of concerns regarding DMBA/AMP Citrate and will consider taking regulatory action, as appropriate, to protect consumers," an FDA spokeswoman, Siobhan DeLancey, said.

If DMBA is found to be a new dietary ingredient or NDI under federal law, failure to file a notification with FDA would render the substance "adulterated" in violation of the Federal Food, Drug, and Cosmetic Act, said Daniel Fabricant, CEO and executive director of the Natural Products Association (NPA).

"Manufacturers of dietary supplements are responsible for ensuring that their supplements are safe and, where required, must submit a new dietary ingredient notification before marketing," DeLancey said. "Our pre-market authority for dietary supplements is limited to the requirement for NDI notification.  We take this matter seriously and are considering the next steps."

Last year, USPlabs, a manufacturer of sports supplements, voluntarily destroyed more than $8 million in products containing DMAA that had been marketed to help with workouts and burn fat. FDA disclosed USPlabs agreed to destroy OxyElite Pro and Jack3d after the agency administratively detained the products under authority that it was granted under the Food Safety Modernization Act. USPlabs still maintained DMAA was safe.

In the letter Wednesday to FDA Commissioner Margaret Hamburg, Durbin and Blumenthal cited escalating evidence of consumer risks associated with DMBA and other designer stimulants.

“If necessary, we urge you to exercise the full range of your authority to rein in adulterated and misbranded products, which includes warning letters to facility inspections, product seizures, injunctions, and criminal prosecutions," the senators wrote. “Our hope is that by calling your attention to studies like the one released today, your agency will take the appropriate steps necessary to remove harmful supplements and protect consumers from any unnecessary health dangers."

CRN agreed that DMBA should not be used in supplements. The trade organization asked FDA last month to investigate DMBA’s regulatory status and recommended consumers don’t purchase supplements that contain the substance.

“Beyond the questionable regulatory status of using DMBA in supplements, if the agency determines this ingredient presents a safety risk, it has numerous enforcement tools available under the law, and we would urge FDA to take swift action against companies that put consumers at risk," CRN president and CEO Steve Mister said in a statement.

One of FDA's enforcement tools is a warning letter to supplement manufacturers. Whether FDA would immediately take more aggressive action against companies selling DMBA depends on various factors, including the agency's resources, priorities and whether the companies received prior notice, said Fabricant, who previously served as FDA's director of the division of dietary supplement programs.  

Fabricant was FDA's supplement chief last year when the company detained DMAA products. In a blog last year, Fabricant said FDA's scientists concluded "DMAA was an unsafe food additive that couldn’t be used in supplements."

Less is known about DMBA.

DMBA "has never been studied in humans," the researchers wrote in the study published Wednesday, and "its efficacy and safety are entirely unknown."

Dave Ellis, past president of the Collegiate and Professional Sports Dietitians Association, expressed frustration with the state of regulatory enforcement against companies that are selling products laced with pharmaceutical ingredients.

"The intentional fraud being perpetrated on consumers almost never results in criminal prosecution by the federal authorities," he said in an emailed statement. "In sports, where our athletes are drug tested, we can't wait for the system to catch up."

He recommended NSF International, the third-party organization that tests and audits products.

“Incidences of product adulteration – whether intentional or not – is a major reason why NSF International developed product testing and certification programs," said John Travis, senior research scientist with NSF International and one of the co-authors of the DMBA study, in an emailed statement. "NSF International dietary supplement certification helps ensure what is on the label matches what is in the bottle and there are no harmful levels of contaminants or unapproved compounds in the product. This helps provide manufacturers assurance that they are providing safer, higher quality products to their customers.”