21 C.F.R. § 208.1 – Scope and purpose.

(a) This part sets forth requirements for patient labeling for human prescription drug products, including biological products, that the Food and Drug Administration (FDA) determines pose a serious and significant public health concern requiring distribution of FDA-approved patient information. It applies primarily to human prescription drug products used on an outpatient basis without direct supervision by a health professional. This part shall apply to new prescriptions and refill prescriptions.
(b) The purpose of patient labeling for human prescription drug products required under this part is to provide information when the FDA determines in writing that it is necessary to patients' safe and effective use of drug products.
(c) Patient labeling will be required if the FDA determines that one or more of the following circumstances exists:
1. (1) The drug product is one for which patient labeling could help prevent serious adverse effects.
2. (2) The drug product is one that has serious risk(s) (relative to benefits) of which patients should be made aware because information concerning the risk(s) could affect patients' decision to use, or to continue to use, the product.
3. (3) The drug product is important to health and patient adherence to directions for use is crucial to the drug's effectiveness.