Study Finds Stimulants in Supplements After FDA Action
A study published in JAMA Internal Medicine on Monday raises questions about the effectiveness of the US Food and Drug Administration’s (FDA) actions to address stimulants found in dietary supplements.While FDA often issues public notices or takes enforcement action aimed at specific companies or products, from 2013-2016 the agency issued public notices warning consumers about four sympathomimetic stimulants found in dietary supplements.
None of the stimulants -- 1,3-dimethylamylamine (1,3-DMAA), 1,3-dimethylbutylamine (DMBA), β-methylphenylethylamine (BMPEA), and methylsynephrine (oxilofrine) -- are recognized by FDA as a dietary ingredient. In the case of DMAA, the chemical was approved as a nasal decongestant in the 1940s, but its approval was eventually withdrawn by FDA in 1983 at the request of its manufacturer.
In addition to the public notices, FDA also issued warning letters to dozens of companies that had listed the stimulants as a dietary ingredient in their products.
For the study, the authors compared samples from 12 supplements that were purchased in 2014 to samples of the same products purchased in 2017.
While the authors found fewer instances of the stimulants in the supplements purchased in 2017, three-quarters (75%) were found to have at least one of the four stimulants present.
“The number of products that contained 1,3-DMAA, BMPEA, and oxilofrine decreased, but most supplements tested contained one or more prohibited stimulant, some up to four years after FDA action,” the authors write, noting that the fourth stimulant, DMBA, was only identified in the samples they tested from after FDA’s enforcement action.
The authors note that the study has limitations, namely that it looked at a small number of brands and tested only one sample from each product.
“Despite these limitations, our study provides further evidence that a regulatory system that relies on postmarket enforcement activities is insufficient to ensure the safety of dietary supplements,” the authors write.
Earlier this month another study published in JAMA Network Open raised similar questions about the effectiveness of FDA’s oversight of dietary supplements found to contain hidden pharmaceutical ingredients such as sildenafil and sibutramine.
In that study, the authors found instances where a supplement subject to a voluntary recall over a hidden ingredient were later found to contain a different hidden ingredient.
JAMA Internal Medicine