Quote Originally Posted by GrowRebel
In some folks hair test can go back years .....
GrowRebel I just answered this yesterday. They can detect drugs in the entire length of the hair but after 90 days it becomes inaccurate. In the U.S. they can only use the last 1 & 1/2 inches of hair growth or 90 days (head hair grows 1/2 inch per month). If you don't believe me check the Quest Diagnostics web site.