Do tattoos show up in a urine drug test?

Absolutely. My response is in contrast to almost anyone you talk to, but I speak from personal experience.

About 5 years ago I was on state parole and subjected to a urine test. All samples are sent to a lab, they don't use any of those instant tests. A couple days prior, I forget exactly how many, I had gotten a large tattoo that covered my entire forearm and took a couple hours. The test came back positive for high amounts of opiates, my P.O. said it had to have been either morphine or heroine. I never took any drugs.

After much consideration, I've determined the false positive has to be one of the following:

1. Human error at the lab. I think this is an extremely slip possibility but it can't be ruled out.

2. Being subject to pain for that amount of time, your brain releases a natural pain killer that is very close in chemical composition to morphine or heroine. I have come across some supporting evidence for this, but I can't seem to track down the source again.

The false positive certainly could have been a lab error, but I still wouldn't risk getting a tattoo if you're subject to regular random drug tests.

Hope this helps.