How Long Does Marijuana Stay In Your Hair Follicles ?

Hair follicle screening is usually used to detect one of 5 commonly used drugs: Cocaine, opiates, marijuana, methamphetamine and PCP.

It works by measuring the drug molecules which are absorbed into the blood stream after the body processes the drug. These molecules are then absorbed by the hair follicle and built into the hair, which can then be analysed later on.

The procedure works by cutting the hair near to the scalp and then analysing the 4cm closest to the scalp. This reflects a period of approximately 90 days, but if a longer piece of hair is analysed then a longer history can be compiled.

Body hair may also be used to screen for drugs and (due to the slower growth rate of this type of hair) substances can be detected up to a year after consumption.

The standard test requires around 40-60 strands of hair, and the variations are dependent on the thickness of the person's hair.

The effectiveness of the drug detection depends on the drug in question, and the quantity and regularity of consumption. The marijuana screen is currently the least effective, being only as good as urine tests, while the other four drugs prove to be far easier to detect in hair samples.

To summarise: The drug molecules are built into the hair, and therefore the screens can detect it if marijuana was used regularly. However, these screens only focus on the last 90 days, so you only need to worry if you've taken it in that period of time.

I have to take a hair follicle test for a job I applied for. I haven't smoked marijuana in 3 months. Will it show up on the test?

Scientific fact... In the test, they can go back as far as 3 years. But as previously mentioned, it all depends on how fast or slow your hair grows, how often you get it cut, and definitely how much you consume and how often. They are all factors.

At least 3 months - 90 days.  It can easily detect it longer than that if the person being tested is a heavy chronic user.

Most tests go back 90 days. Each .5 inch represents 30 days. Your best bet is to cut your hair short, and use Nair to remove body hair. You may be able to get a urine sample due to the fact that they will not be able to extract hair.

When hair grows everything you ingest is there until you cut it out (hair-cut) If they test only the follicle then it should be clear, however, if your hair is slow growing it may still show up.

I'm told it depends on the amount of usage - as in light, mild, or heavy usage - but on average 90 days. But if you factor in pregnancy, where the hair grows faster, it could be cut down by a month

I recently read online that those can only be taken back 90 days.

It only takes 90 days, so you should be fine.

The hair test will detect any drugs you have taken for 6 months.

I'm not sure but it is a long time. Maybe 6 months to a year. I have heard of people shaving all of their hair off.

Yes you do need to worry. It may take anywhere from 90 to 120 days for your body to entirely purge all the residue of marijuana. Don`t jump in for those remedies offered online for most of them are scams or just myths. There is no way you can possibly pass a drug test if it's less than the aforementioned time period. The only other way is to bribe someone in the system, if you can find a weak link that is, and have someone else's hair tested in your stead.

30 days

Yes it stays a long time but I don't know how long.