What is the term for a drug used for a purpose not approved by the FDA?

The term for a drug used for a purpose not approved by the FDA is "Off Label." This designation refers to the practice where a physician prescribes a medication for a condition, dosage, or population that has not been specifically approved by the Food and Drug Administration. This practice can be common in medical treatments, as physicians may find that a drug has beneficial effects for conditions beyond its original approval based on clinical experience or emerging scientific evidence.

Using medications off-label is legal and often necessary, as it allows for flexibility in treatment options when patients have conditions that might not be well-served by only FDA-approved indications. It is important for healthcare providers to ensure that they rely on sound clinical judgment and the best available evidence when prescribing off-label.