I want to get some opinions on the likelihood of passing a hair follicle test. I smoked most of September at least 3 times a week. How long would that amount of marijuana stay in my system for a hair follicle test?

When is your test?

A hair drug test is meant to show consistent use over time. A 1.5 inch sample, cut at the scalp line, will go back 90 days. As long as your hair is 1.5 inches long on the head it can be used to detect THC. At this point I am fairly confident you would be positive if you took a test in the near future. The big question I have is, did you smoke any marijuana in July or August?

Short answer is that the drug will "stay in your system (hair)" for as long as your hair is and as long as you have been using. It does not dissipate or go away by any means other than cutting the hair off. Hair grows on the scalp at an average of 1/2 and inch a month. Let's say you have been a average/heavy, regular smoker since January and they take a 5" sample of hair. In theory, you should test positive for the past 10 months.

However, cutoff levels, actual quantity & quality (amount of THC) all play a factor. For example, I smoked 2-3x/week for months and tested negative on a hair test. I would usually take 2-3 hits of some really good, medical grade mj. So, while my use was fairly regular, the quantity was not enough to be over the cutoff level they were testing for.

"Drugs are deposited in the hair shaft through absorption into the hair follicle. Testing is conducted on the hair shaft which prevents external contamination on the outside of the hair that may occur during accidental exposure, such as being in the same vicinity as someone using drugs."