You can't....everything stays in your hair.....a hair follicle test can tell how if you've ever taken any kind of drug in your life....how many times you've done it....and if you've stopped it can tell how long ago you've quit...
How Can I Pass A Hair Follicle Test For Cps?
Drugs stay in the hair for three months AFTER you become clean. Each drug lasts in your system for a different amount of time.