the only drug
that I know of that does not follow suit with the rules
of this 1.5" inches = 90 days deal, is cocaine
, as it is thought to travel fluidly up and down the hair shaft, contrary to the timeline behavior nearly every other drug exhibits in the hair shaft.
Ie, you have 8" of hair, they clip 1.5" off from the base of your scalp, that 1.5" is 90 days of past drug use. However a year ago you did cocaine. That can travel down into the "90 day" zone, even if you didn't use it within 90 days.
This was the case with hair follicle testing 10yrs ago, if a new procedure has been implemented, idk. There is a hair shampoo that I can co-sign on made by zydot, I would use this in conjunction with abstinence.