According to a research letter in JAMA, dietary supplements recalled because of the presence of pharmaceutical adulterants still contain the banned ingredients months after the recall.
They looked at 27 dietary supplements that were recalled between 2009 and 2012 because of pharmaceutical adulterants. Researchers purchased the supplements at least 6 months after recall for analysis of banned ingredients.

Roughly two thirds of the products tested positive for at least one pharmaceutical adulterant — usually the same ingredient identified at the time of the recall. One fifth of all products contained additional banned ingredients. Among the adulterants identified were sibutramine (wt loss agent), sildenafil (Viagra), fluoxetine (antidepressant), and anabolic steroids.

The researchers conclude: “Action by the FDA has not been completely effective in eliminating all potentially dangerous adulterated supplements from the US marketplace.” They call for “more aggressive enforcement of the law, changes to the law to increase the FDA’s enforcement powers, or both.”

JAMA