If you are not a regular user you should be safe after 8 days. If you have been a regular user (2-4 times/week) it will take as much as 35 days to get out of your system. If you use daily it can take as much as two months. These times are for urine tests, if your hair is tested then any hair on your body when you last used will show positive. Just to be safe, get a haircut.