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Scheduled for hair follicle test. Have not smoked cannabis since months. Will I fail the test?

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Practicing since : 2003
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I will be undergoing a hair follicle test, for a new job. I have not smoked cannabis in 7 months. I was a moderate user prior to that. WIll i fail?
I should add, I have been very active since quitting, lost a half a stone. And shaved and regrown my head and body hair. I keep my head hair shaved tight, i anticipate a sample will be taken from my body hair.
Posted Tue, 4 Jun 2013 in Skin Hair and Nails
Answered by Dr. R.G. Joshi 50 minutes later

Thanks for writing to XXXXXXX

Hair follicle test usually detects metabolites of Weeds.

Active metabolite of cannabis is tetrahydrocannabinol (THC),when ingested orally it accumulates in the bulb of hair shaft where it can be detected.For test to become positive minimum interval of 3 to 10 days are required.

Our head hair grows half an inch per month. Usually standard protocol is to test one and half inches of head hairs which can detect drugs taken 3 months back. But body hair can detect drug up to 1 year.Also positive test depends on amount of drug ingested,frequency of ingestion since test can not detect trace amounts.

Since you have not smoked cannabis in 7 months in moderate dose there will be chance for you to pass test if your head hairs are taken. So do not shave your head hairs and keep them as long as possible so that samples can be collected from scalp itself.

I hope this can solve your query,if you have any concerns, I am ready to help you.
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Follow-up: Scheduled for hair follicle test. Have not smoked cannabis since months. Will I fail the test? 28 minutes later
I will not have a chance to grow adequate hair. Do you think my body hair will fail me?

Answered by Dr. R.G. Joshi 10 hours later
Hi thanks for follow up.

Many studies have shown that there are more chances of passing a test if hair is taken from head.

Body hair is slow to grow than head hair and therefore they can detect toxins up to 1 year. I m afraid you may fail test if body hair is taken. But there is some good news for you, body hair tests are not so much accurate and they never detect trace amounts. Since you have already passed 7 months without drug and you are active there may be a fair chance that toxins can be eliminated from your body and you may pass.

So hope for the best.

Best wishes.
Above answer was peer-reviewed by
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