Don't listen to them. It does not show up on a standard drug test unless that is one of the drugs they are specifically looking for. Fentanyl does not show up on a standard 5 9 10 or 12 panel test. It is not like morphine because it is a man made synthetic drug. I was wearing the 100mcg patches for a full year when I shouldn't have been but I have chronic low back pain and failed back syndrome due to multiple surgeries. A family member was giving them to me for pain because percocets would not phase my pain. Anyway I had a random drug test for work and have been wearing the patches for six months and I had a one day notice, so I was freaking out. After research of my own I'd figured out that I would be ok. I went in and took the test with the patch on my arm, NO JOKE. And I passed it didn't show up at all because it was a 10 panel screen. So to answer your question no it doesn't. But remember be careful with these patches or any other meds that aren't prescribed to you. Good luck.