Believe it or not, I don’t take drugs, even pot, because it makes me paranoid. And my job doesn’t test anyway, so there’s no ulterior motive or desire to figure out ways to “cheat” a drug test. I’m merely curious: how does the test where they take a hair sample work? I’ve heard for years how effective it is, how it can detect drug use from five years ago, blah blah blah. My question: how can it be so powerful? Do they only take one hair, or many? Doesn’t your “old” hair get pushed out by new hair anyway? Why would “new” hair (supposedly) contain traces of drugs from so long ago? I did a search on “drug tests” and while I found references to the hair test, nobody explained how it worked. Enlighten me.
I suspect the answer is that hair you see is no longer living so it is essentially static in chemical composition. Only the subdermal part is living, and as it grows it pushes out the dead portion making it longer and longer. Therefore if you have long hair, the portion that died five years ago would containt traces of the drugs you took then. It would just involve estimating how fast your hair grows to determine how long ago you took the drugs.
IIR, hair grows about 6 inches a year, so five years would make 30-inch hair. You don’t see many people with hair longer than that, so that would be why they phrase five years as a maximum, “up to”.
It looks as if you stop using drugs and wait a week or two and shave your scalp (and everything else), bye-bye hair evidence.
Is the hair test supposed to find any drug (marijuana, opiates, amphetamines, tranqs, …)? It doesn’t seem likely. What changes does a drug make in the hair chemistry or structure, or do molecules of a drug get taken up by the hair as it grows?
Yeah, that’s more along the lines of what I’m trying to find out. It doesn’t seem to add up, somehow.
slight hijack
say they found out that you did five years ago. would anyone care? if it was the cops, could/would you still be arrested? if it was for a job, would you be likely to still get the job?
I’m pretty sure there’s a statute of limitations on any drug use, and I’m pretty sure it would be less than five years, but then again IANAL. As for the job, I’m sure it depends on what company, and for what kind of job.
Hair itself* lasts for five years in the presence of sun, oxygen, and water because it is strong, I believe a protein. How many other molecules would last as long?
I doubt all the more that all or most drugs would show up, especially after a year.
Not to doubt the statements of those in authority who may be responsible for our well-being, of course.
*some people’s, not everyone’s