Quote Originally Posted by OhxMuffins
Anyways.. Hair tests can tell what you've hit from like, fuckin 6 months ago. If you'ew real worred, shave your head!
By federal guidelines, they can only go back 90 days for drug use because it becomes inaccurate. They are not testing her to see if she was poisoned. They could test the entire length of hair but the only results that are valid in drug testing is from the last 90 days. This is here in the U.S.A. I have heard that the length of time they can go back is different in some countries.

Shaving your head, bad advice. If you have no hair at all on your body, no test, automatic failure. Also they can use your nails.