[BOB1347]

Dr. Bill, I took my hair drug test today. They took maybe an inch from my armpit hair. I last smoked once mid January and once end of February. Very Rare smoker, smoked maybe 4 times my whole life. What do you think my chances are?

[DrBill100]

Probably better than if head hair was used. Hair is a very poor medium for testing for THC and metabolites. It takes pretty substantial use to test positive in hair.

While axillary (arm pit) hair is thicker and darker (influencing some drugs) those characteristics are of little value in testing for cannabis use. THC & particularly THC-COOH incorporate into hair in very low quantity requiring frequent and prolonged use for detection.

Axillary hair provides a longer detection period but with THC it is quantity that is the determining factor.

In your case it is the amount and infrequent use that is the savior not when last used.

Why was axillary chosen rather than head?

[BOB1347]

I cut my hair a week before they told me about the test,they told me I was going to take one two weeks ago. It had not grown too a long enough length. They went directly to the armpit hair. Would September/October, only one smoke each month have any bearing on this recent test?

[DrBill100]

I cut my hair a week before they told me about the test,they told me i was going to take one two weeks ago. It had not grown too a long enough length. They went directly to the armpit hair. Would September/October, only one smoke each month have any bearing on this recent test?

Should not. In relation to head hair a general rule is twice weekly or more, but that varies. Hair testing for cannabis only detects heavy daily use in about 65% of cases. The folks paying for and relying on hair testing for THC (more expensive than urine) aren't spending their money wisely.

Don't mean to say that hair testing is ineffective in all cases. It works well for some drugs, cocaine in particular, opiates, but not cannabis.

[BOB1347]

You mentioned previously that it was better that they took my auxiliary hair rather than my head hair. Why is that?

[DrBill100]

The incorporation rate for THC/COOH is even lower than head hair. But not much research on the subject.

Also, there is not the opportunity for external contamination that plagues head hair via sebaceous and sweat glands.

[BOB1347]

Does exercising help the cause of getting the toxins out of the hair or no?

[DrBill100]

Does exercising help the cause of getting the toxins out of the hair or no?

Not at all.

[BOB1347]

Not at all.

Many people have said that arm hair holds a longer detection period, because of the slow growth rate. But like you have stated before it would only seem to hold for a heavy smoker. What would you define a person who smokes maybe once every two months or less? And what are their chances for passing a hair test, if taken from auxiliary hair?

[TAnner31]

I smoked maybe a month and a half ago is and last Friday is there a chance I can pass a hair test when they took hair from my pits

[DrBill100]

I smoked maybe a month and a half ago is and last Friday is there a chance I can pass a hair test when they took hair from my pits

The question isn't the time from last time smoked, in most cases, rather how much and how frequently you smoked prior to that last use.

The difference between terminal and axillary (arm pit) hair is growth rate. The drug incorporation (absorption) is nearly equivalent to scalp. So, once again, it is whether the frequency and amount smoked was sufficient to incorporate into hair.

[Didymus23]

I have been smoke free for a year and a half. I gave an arm hair sample. Will I test positive for marijauna?