Hi I was wondering just how the hair tests worked for marijuana. Hypothetically speaking, if a person smoked for the first time ( lets say last week) I'm wondering how long it will take for them to get clean. What I mean is if a lab needs the first 1.5 inches of hair which takes on average 90 days to grow how long will it take for none of their hair to show traces of THC? On average how long will it take the hairs on their head and body to show no traces of THC while growing?
bsynder21 Reviewed by bsynder21 on . Hair test Hi I was wondering just how the hair tests worked for marijuana. Hypothetically speaking, if a person smoked for the first time ( lets say last week) I'm wondering how long it will take for them to get clean. What I mean is if a lab needs the first 1.5 inches of hair which takes on average 90 days to grow how long will it take for none of their hair to show traces of THC? On average how long will it take the hairs on their head and body to show no traces of THC while growing? Rating: 5