Key Issue: Heparin


Original Posting: 21–Aug–2009; Last Update: 22–Jul–2013


  • Scientific Liaison: Anita Szajek ( or 301-816-8325)
  • Reference Standards Technical Support: RS Technical Service ( or 301-816-8129)
  • Reference Standards Ordering: USP Customer Service ( or 1-800-227-8772)
  • Media: Theresa Laranang-Mutlu ( or 301-816-8167)


  • Heparin Labeling Clarification (22Jul2013): The labeling sections of the currently official Heparin Sodium Injection and Heparin Lock Flush Solution monographs in USP–NF have been revised to ensure that labels comply with General Chapter <1> Injections. Implementation date for this labeling change was May 1, 2013. General Chapter <1> requires that the label reflect strength per total volume as the primary expression of strength, followed in close proximity by strength per milliliter (mL). An example of an expression of product strength as articulated in General Chapter <1> would be “30,000 USP Units/30 mL (1000 USP Units/mL).”

    Note that heparin-related labeling, e.g. on the containers, need not use the full phrase “USP Heparin Units” that appears in many heparin monograph labeling sections. The term “USP units” can be used on heparin labeling consistent with USP compendial requirements, provided it is clear from the context that the volume is stated in terms of USP Heparin Units.  In such circumstances it should be clear that “USP Units” and “USP Heparin Units” share the same meaning.

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