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Prohibited stimulants still in many dietary supplements

Many dietary supplements contain stimulants that have been prohibited by the FDA, including 1,3-dimethylamylamine, 1,3-dimethylbutylamine, beta-methylphenylethylamine and methylsynephrine, according to findings published in JAMA Internal Medicine.

“The FDA is responsible for eliminating adulterated and potentially hazardous dietary supplements from the marketplace,” Pieter A. Cohen, MD, associate professor of medicine at Cambridge Health Alliance, and colleagues wrote. “The FDA uses a variety of enforcement actions, including public notices, to remove potentially hazardous ingredients. However, it is not known whether public notices are effective.”

Between 2013 and 2016, the FDA issued public notices regarding four prohibited sympathomimetic stimulants in dietary supplements, including 1,3-dimethylamylamine (1,3-DMAA), 1,3-dimethylbutylamine (DMBA), beta-methylphenylethylamine (BMPEA) and methylsynephrine (oxilofrine). Cohen and colleagues examined whether the public notices were effective at eliminating the presence of prohibited stimulants by comparing supplements before and after the notices were issued.

The researchers analyzed 21 brands of supplements from 2014, of which 12 (57%) were still on the market in 2017 and therefore included in the current analysis.

Despite the FDA notice about the use of 1,3-DMAA in 2013, the ingredient was present in six of the 12 supplements (50%) purchased in 2014.

In 2017, 75% of the supplements purchased contained at least one of the four prohibited stimulants and half contained two or more.

In 2014, DMBA was not identified in any supplement purchased; however, it was detected in 33% after the FDA released its public notice on the stimulant in 2015.

“Our study provides further evidence that a regulatory system that relies on postmarket enforcement activities is insufficient to ensure the safety of dietary supplements,” Cohen and colleagues concluded. “Practitioners should advise patients that dietary supplements may contain prohibited stimulants.” – by Alaina Tedesco

Disclosures: Cohen reports collaborating with NSF International and receiving research support from Consumers Union. Please see study for all other authors’ relevant financial disclosures.