You may ask exactly
how long is weed in your hair. Actually, there is no simple, definite answer to the question. That is because the principal psychoactive constituent of cannabis called THC is fat-soluble, not water-soluble, and it can stay in your body for a period of time from a few hours to 90 days and more.
For those who are likely to face a hair drug test, here are some facts and tips you should know.