I don't know dude but if you use the omni cleansing shampoo it works. I had 2 take a hail test when my ex wife accused me of doin mad oxycontin and took away my visitation with my daughter. Tha place any lab test cut my hair 2 the scalp and sent it to a lab. I passed. I stayed clean for 2 I/2 months with the exception of 3 oxys. Just follow directions 2 a t. I don't know if they pluck at the root if it works but tha way they cut it it did. I live by the omni cleansing shampoo! it made my ex wife look like an idiot and she dropped the case :)