On-label and off-label drug use in the treatment of endometriosis.

Endometriosis, characterized by the presence of endometrial glands and stroma in extrauterine locations, is a significant cause of pelvic pain and infertility, as well as a major health care burden. Although Food and Drug Administration (FDA)-approved treatments are available, the use of "off-label" medications for endometriosis is widespread. In this review, we provide an overview of the current FDA-approved treatments, followed by a detailed review of the major "off-label" treatments being used in the United States and worldwide, including efficacy, side effects, drug interactions, contraindications, and anomaly risks.