How long does Ritalin stay in your hair?
Ritalin or Methylphenidate is a prescription drug. It can stay in your hair cells for up to 90 days after you use it.
If you are getting a drug test via hair strand test and you have done something you shouldn't have since the last time you shaved your head, your busted. Your hair is the history of your drug use. In other words, if you have done Ritalin since the last time you cut your hair, considering you shave it bald, it will show up.