Help me avoid screwing up my future from one mistake...

March 4, 2010 2:49 PM

Will I pass a drug test for THC? Yes, I've read previous questions, but this is different.

I smoked once on December 17th, 2010. This was my first time to smoke in over 2 years. Was so out of it I actually threw up (hoping this means I didn't metabolize much).

Now am required to take a drug test for an internship "You are required to provide a urine drug screen and a hair sample collection."

Kicker is that it is within the next 3 days.

How screwed am I? My hair is currently about 2.5 inches long at its longest point. Should I cut it? Help!

Thanks!

posted by anonymous to Science & Nature (9 answers total)

You will pass urine screening. The old "30 days to clean" adage only applies to heavy smokers.

I don't know about your hair though. Seems like one time two and half months ago wouldn't show up, but I don't know the real answer.

Good luck.
posted by damionbroadaway at 2:55 PM on March 4, 2010

It's March, that was almost three months ago. THC takes 6 weeks to leave your system. You're fine. They're taking your hair to check for regular hard drug use. You haven't got hair longer than 2 years old on your head. But your hair grows 1/2 an inch per month, that's 3 inches if it grows reasonably fast. You should be fine. I'm not an expert on how sensitive the hair testing is, but I seriously doubt it's going to pick up one night of toking three months ago if that was the only time you've done it. I'm 99% sure you're fine.
posted by lizbunny at 2:56 PM on March 4, 2010

Here is a FAQ on hair testing.


3. What time period does a standard test cover?
A standard test covers a period of approximately 90 days. The hair sample is cut as close to the scalp as possible and the most recent 1.5 inches are tested.

Doesn't say what the threshold is, but it would be my guess that one time would not set it off, just a guess though.

If you shave your head they will ask for body hair.

There are some extreme extreme cleaning methods people apparently tried. Not sure I would trust to that.

Erowid says: The liquid is run through the most sensitive GC/MS machines available, and can detect as little as 1 ng/mL!

I have no idea if that means one smoking session would do it or not.
posted by furiousxgeorge at 3:08 PM on March 4, 2010

The urine test - you're fine.

The hair test - imho you're screwed. I don't know from any personal experience, but my impressions were and research done was that they are very sensitive and that because the hair has anything you've metabolized - its in there and they'll find it.

If you do get popped, deny deny deny deny deny deny. Absolutely deny everything and demand another test.

Good luck!
posted by ish__ at 3:32 PM on March 4, 2010 [1 favorite]

They're taking your hair to check for regular hard drug use.

I'm not sure if that answer meant to imply that they do not test for marijuana. Just in case, I can tell you I was required to take a pre-employment hair test several months ago, and they did test for marijuana. They cut approximately 150 hairs from one or two sections (depending on the thinness of your hair), and they cut the hair at the scalp. If they cannot get the hair they need from your head, they will take from other areas. If you are completely hairless everywhere, my understanding is they will take a buccal (inside your cheek) swab (I don't know that to be true, though).

I would cut your hair short, but not ridiculously short. If you don't pass, is there any chance you have a stamp in your passport that proves you were recently in a country that has legalized marijuana? I'm not sure that would be good enough, but if you were following the laws of the country you were in, I think that would present a gray enough area to at least have a conversation.

Good luck!
posted by Houstonian at 4:15 PM on March 4, 2010

If you get a hair cut (not shave), you will still get tested from your scalp hair, but they will only get recent growth -- hopefully post-drug.

I have no specific knowledge, but no one has mentioned this so I thought I'd bring it up.
posted by grobstein at 4:16 PM on March 4, 2010

Was so out of it I actually threw up (hoping this means I didn't metabolize much).

I don't think this makes any sense. Smoke enters the bloodstream through the lungs, not the stomach.
posted by DU at 5:35 PM on March 4, 2010 [2 favorites]

I think you should cut your hair down to an inch at the longest. You've had probably at least an inch of growth since December, and I think if you lop off 1.5" you will effectively remove enough of potential THC to pass the test.
posted by sickinthehead at 6:20 PM on March 4, 2010 [1 favorite]

woah dude you smoked in the future, thats so radical, man. December 2010. (sorry, I'm just playing)

Anyways. You will pass a pee test. The THC could show in a hair test. The thing is though, the concentration needs to be high enough for you to fail the test. You can still show drugs in your hair, but if they are below the "fail" threshold, you will pass. A haircut could lop off the affected area entirely. I highly doubt in any case that one time smoking would cause high enough THC concentrations to fail the test.
posted by WeekendJen at 1:01 PM on March 5, 2010