Warning Letters and Responses
A Warning Letter is an informal advisory, to a firm or clinical investigator, communicating the Agency's position on a matter but does not commit FDA to taking enforcement action. A Warning Letter is issued for significant regulatory violations that require prompt and adequate corrective actions.

Warning Letters and Notice of Violation Letters to Pharmaceutical Companies
These letters, sorted by month, are supplied by the CDER Freedom of Electronic Information Office.

Notice of Initiation of Disqualification Proceedings and Opportunity to Explain (NIDPOE) Letters
The NIDPOE letter informs the recipient clinical investigator that FDA is initiating an administrative proceeding to determine whether the clinical investigator should be disqualified from receiving investigational products pursuant to FDA's regulations. Generally, FDA issues a NIDPOE letter when FDA believes it has evidence that the clinical investigator repeatedly or deliberately violated FDA's regulations governing the proper conduct of clinical studies involving investigational products, or submitted false information to the FDA or the sponsor.

Notice of Opportunity for Hearing (NOOH)
The NOOH provides a clinical investigator with the opportunity for a hearing on a regulatory action, including a proposed action (such as disqualification). The regulatory hearing is held before a presiding officer designated by the Commissioner.

Adequate Assurances List for Clinical Investigators
This list contains the names of clinical investigators who have provided FDA with adequate assurances of their future compliance with requirements applicable to the use of investigational drugs and biologics.

Restricted List for Clinical Investigators
This list contains the names of all clinical investigators who have agreed to certain restrictions with respect to their conduct of clinical investigations.

Disqualified/Totally Restricted List for Clinical Investigators
This list contains the names of clinical investigators who have been disqualified or "totally restricted." FDA may disqualify a clinical investigator if he/she has repeatedly or deliberately failed to comply with all applicable regulatory requirements or the clinical investigator has submitted false information to the FDA or the sponsor.

Debarment List
This is a public list of firms or persons debarred pursuant to sections 306(a) and (b) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 335(a) and (b)) as published in the Federal Register.