A recent study looked at 3132 dietary supplements and found 875 to contain “undeclared substances.” More than 28% of the analyzed dietary supplements pose a potential risk of unintentional doping. Most frequently found were: sibutramine and anabolic-androgenic steroids!!
“They don’t clean their machinery, and next thing you know, trace amounts of banned substance are finding their way into a product.” Read more about this from this excellent article here.
As a #sportsdietitian I continue to only recommended products that are NSF Certified @nsfcertforsport or third party tested, like Informed Choice. You can download both of these apps and search to see if your product is listed. These certifications mean that a product is guaranteed safe, clean, contains what is on the label, and is free of other contaminants too. This is necessary even for something like a protein powder due to the high risk of cross contamination for banned substances or other substances like lead, arsenic (see Clean Label Project).
Study: PMID: 35496041