WEDNESDAY, Oct. 24, 2018 (HealthDay News) -- Many supplements contain one or more stimulants that have been the subject of U.S. Food and Drug Administration-issued public notices, according to a research letter published online Oct. 22 in JAMA Internal Medicine.
Pieter A. Cohen, M.D., from the Cambridge Health Alliance in Somerville, Mass., and colleagues examined the effectiveness of the FDA's public notices issued between 2013 and 2016 targeting prohibited sympathomimetic stimulants in supplements. Supplements purchased in 2014 and the same brands purchased in 2017 were analyzed to determine the presence of prohibited stimulants.
The FDA issued notices regarding four prohibited sympathomimetic stimulants during Jan. 1, 2013, through Dec. 31, 2016. Fifty-seven percent of the 21 brands of supplements analyzed in 2014 were still available for purchase in 2017. The analysis included these 12 brands. The researchers found that of the 12 supplements purchased in 2014, 50 percent contained 1,3-dimethylamylamine. Of the 12 supplements purchased in 2017, 75 percent contained at least one of the four prohibited stimulants. 1,3-dimethylbutylamine was not detected in any supplement purchased in 2014 but was detected in 33 percent of the 12 supplements purchased in 2017 after the public notice was issued in 2015.
"Our study provides further evidence that a regulatory system that relies on post-market enforcement activities is insufficient to ensure the safety of dietary supplements," the authors write. "Practitioners should advise patients that dietary supplements may contain prohibited stimulants."
Two authors were subjects of civil law suits brought by Hi-Tech Pharmaceuticals, a supplement company, regarding β-methylphenylethylamine.