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USP-NF Standard Updates

USP–NF's Continuous Revision Process and Superseded Text

The United States Pharmacopeia–National Formulary (USP–NF) is continuously revised. Revisions are presented three times a year in the USP-NF as Issues 1, 2, and 3, and as monthly Accelerated Revisions on the USP website. USP uses its Accelerated Revision processes to expedite revisions to the USP–NF. Accelerated Revisions include Revision Bulletins, Interim Revision Announcements (IRAs), and Errata.

Accelerated Revisions: Revision Bulletins, IRAs, & Errata

  • Revision Bulletins are USP's most expedited revisions and supersede standards published in the USP–NF (print and online versions). A Revision Bulletin posted on the USP website indicates its posting date and official date.
  • IRAs are proposed in PF for a 90-day public comment period. Once comments (if any) are reviewed and the IRA is approved by the appropriate Expert Committee, final IRAs are posted on the USP website. Like Revision Bulletins, IRAs supersede standards published in the print and online USP–NF. IRAs are incorporated into the next available official publication.
  • Errata are considered to be text erroneously published in the USP–NF that does not accurately reflect the intended requirements as approved by the Council of Experts. Errata are posted on the Web site and are official the first day of the following month. Errata are incorporated into the next available official publication.

Once published in the print and online publications, Revision Bulletins and IRAs are official as of the date indicated on the website and are not subject to the general six-month delayed official date for the particular publication.

Learn more by visiting the Accelerated Revision History and the USP Guideline on Use of Accelerated Processes for Revisions to the USP–NF. To receive periodic email updates when USP posts New Official Text, sign up for the free Compendial Updates service.

Harmonization Stage 4

Harmonization Stage 4 includes monographs or general chapters that have completed stages 1-4 of the pharmacopeial harmonization process resulting in approved USP–NF text. Stage 6 adopted text is published so that USP–NF users may become aware of its availability as a pharmacopeial standard and its targeted official date. View current Notices of Stage 4 Harmonization.

Learn more about the harmonization process by visiting the Harmonization—Pharmacopeial Discussion Group section of USP's website.

USP Reference Standards Information

Lists of "New USP Reference Standards" and "Unavailable First-time Official USP Reference Standards" are provided below. Visit the USP Reference Standards Catalog and the online USP Store for a complete listing of available USP RS's and to obtain RS documentation (e.g., USP Certificates, SDS), lot validity, and more. Click here to subscribe to our newsletter, The Standard, to receive a monthly snapshot of new and updated RS's.

  • New USP Reference Standards (updated as of July 24, 2020)
    The following USP RS, which were not available when the associated monograph was made official, have since become available. The respective official date of each USP–NF standard, test, or assay requiring the use of the following USP RS is indicated in parentheses after the name of the RS.
    • No changes to post
  • Unavailable First-Time Official USP Reference Standards (RS) (updated 22–Feb–2022)
    • The official dates of any portion of USP–NF tests or assays requiring the use of the following never-before-released USP RS's are postponed until further notice pending availability of the respective RS. 
      • USP Alteplase RS
      • USP Aprotinin RS
      • USP Aprotinin System Suitability RS
      • USP Sargramostim RS