Off-label prescribing, also known as unapproved use, is the physician practice of prescribing a drug or medical device for a purpose different from one of the indications for which the product is approved by the Food and Drug Administration (FDA). The practice is widespread. The practice raises a number of legal and ethical issues.

Is off-label prescribing a form of human experimentation, triggering the safeguards established to protect human subjects? Could a failure due to off-label prescription leave the physician vulnerable to a malpractice suit?