Can anyone tell me which test is more accurate: a scalp hair test or a body hair test. We have 2 test that were taken on the SAME day & 1 shows positive for methamphetamine and 1 shows negative. It should show negative! We are at a loss as to how a test that is so accurate has 2 different results. Is there any way that "exposed" hair like scalp hair can be contaminated where "covered" hair like body hair wouldn't be. I do not doubt that where this person works, they could have been exposed to all sorts of things, but I find it hard believe if it was ingested that it wouldn't show up on a body hair test.

Thank you

It appears that hair from the head shows more recent drug usage than hair from the body: " body hair can be used to test for the five standard drug classes, though body hair growth patterns are different than head hair. Most body hair is replaced within approximately one year. This means a test done with body hair will be reported as drug usage during approximately a one year timeframe."

Omega Laboratories - Hair Testing FAQ

Thank you for your quick response. I believe you are saying the scalp test would be the more accurate. If that is the case is there ANYTHING that would cause a positive result if no methamphetamines were done? I've known this person for years and been around them on a daily basis for over 3 of those years and I just do NOT believe that they have used anything and certainly not methamphetamine.

Thank you again

There is some useful stuff here:

Psychemedics Corporation