medical - what is sl
Best Answer: It means sublingual, which means put it under your tongue. Any prescription contains several pieces of information: -the name of the drug. -the dose of the drug. -the route of administration - po=by mouth, iv=through an iv, im=intramuscular (a shot), sl=sublingual, and so on. -the frequency of dosing - i.e. once a day, every four hours, etc.