Do I need to let my empoyer know of my Vicodine prescription last month before my hair folical test next week? Also how do vicodine or norcos show on the hair folical test can they see it was a prescribed narcotic or does it register as illegal?

I would definitely recommend providing a copy of your prescription.

Both Vicodin and Norco contain hydrocodone (Hyd) a semi-synthetic opioid. How and even if it shows up on a Hair Drug Test (HDT) is largely dependent on the specificity of the test and testing facility.

All HDTs check for opiates (via morphine) but many do not detect the synthetics as they do not breakdown into morphine. However, expanded drug screens can detect this class and they can be specifically tested for. So in one type of screen if Hyd was detected it could register as an opiate* while in a more specific test (confirmatory) it could be specifically identified by it's metabolites.

No drug test can determine the source of the drug, illicit or prescription. It is only a valid prescription that makes this distinction, therefore my recommendation.

*Hyd cross-reacts with many commercial IA opiate screens even though it contains no morphine.