re: How precise are hair follicle tests?

Your fine even if your use was double that over the same time frame here is why.

Hair follicle testing is looking for build up from habitual use.

Misconception on the street is they can go back only 90 days. Truth be told its about a year.

Misconception is that you can use washes and so forth to fool test. absolutely false.

a 3 day bender of coke and whores isn't going to show anything. But if you took a bump every two days for a month your screwed. same with most pills and THC