Once a new medication or device is cleared for marketing by the U.S. Food and Drug Administration (FDA), the medication or device is available to physicians and patients. In the United States, FDA regulations permit doctors and other healthcare providers to prescribe approved medications and devices for indications other than the disease or condition for which they are approved; this is called off-label use.

Off-label use does not mean unsafe use. The FDA allows doctors to make informed decisions about the best medication or device to treat their patients, and doctors may prescribe a medication or device in a way that has demonstrated positive outcomes but is not "indicated" or FDA-approved for that specific use. If doctors were not allowed to prescribe off-label, lengthy FDA approval processes for each medication or device might prevent patients from receiving life-saving therapy.

It is important for doctors and patients to discuss the best method of treatment and all medications and devices available to treat a condition. However, device and pharmaceutical companies are prohibited from promoting their products for any other purpose unless they first receive FDA approval for a new indication.