OPSS has received a number of questions about whether dietary supplements—especially those used for bodybuilding and weight loss—could result in a positive result on military drug tests. Military drug testing begins with urine, which is first screened and then followed by additional tests depending on the outcome of the screen. You can get extensive information about DoD’s drug policy and drug testing from the Drug Demand Reduction Program (DDRP), including military testing. And for answers about the potential effects of specific dietary supplements on drug screening tests, you can contact your service’s military drug-testing laboratory by phone or email (list below). Positive urinalysis results due to dietary supplement use can occur because products on the market may contain undeclared drug ingredients—that is, controlled substances that are not stated/ listed on the product label. More information can be found in the FDA Consumer Update. There you will also find information about how to get updates about products FDA has identified as tainted. There is no way to know if a particular supplement contains an undeclared drug without laboratory testing, but FDA does keep track of such  products once identified through its MedWatch program. https://www.opss.org/articles/dietary-supplements-and-drug-testing