Those dietary "supplements"
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Half of the products tested contained undetectable amounts of the labeled ingredient. Only 11% were close to the amount on the label.
Results
Of the 63 products purchased, 6 did not list 1 of the 5 ingredients on the label; therefore, 57 products were analyzed (13 listing R vomitoria; 21, methylliberine; 8, turkesterone; 7, halostachine; and 8, octopamine). Twenty-three of 57 products (40%) did not contain a detectable amount of the labeled ingredient. Of the products that contained detectable amounts of the listed ingredient, the actual quantity ranged from 0.02% to 334% of the labeled quantity (Table). Six of 57 products (11%) contained a quantity of the ingredient within 10% of the labeled quantity.
Seven of 57 products (12%) were found to contain at least 1 FDA-prohibited ingredient (Table). Five different FDA-prohibited compounds were found, including 4 synthetic simulants, 1,4-dimethylamylamine, deterenol, octodrine, oxilofrine, and omberacetam. Six products contained 1 of these prohibited ingredients, and 1 product contained 4 different prohibited ingredients.
Discussion
Eighty-nine percent of dietary supplement labels did not accurately declare the ingredients found in the products, and 12% of products contained FDA-prohibited ingredients. A prior study4 of dietary supplements, before the FDA ephedra ban, found that 6 of 12 products (50%) contained ephedra within 10% of the labeled amount. In a more recent study5 of caffeine content of sports supplements, 9 of 20 products (45%) contained a quantity of caffeine within 10% of the labeled quantity. In the current study, which to our knowledge is the first to quantify these 5 supplement ingredients, only 11% of products were accurately labeled and 5 different FDA-prohibited ingredients were found, including an unapproved drug available in Russia (ie, omberacetam), 3 drugs formerly available in Europe (ie, octodrine, oxilofrine, and deterenol), and 1 drug that has never been approved in any country (ie, 1,4-dimethylamylamine).6
