As a patient safety measure, USP has changed the labeling standard for Heparin Sodium Injection USP and Heparin Lock Flush Solution USP. The new standard requires manufacturers to clearly state on the label the strength of the entire container of the medication followed closely by how much of the medication is in each milliliter. The standard becomes official May 2013, and we know that some manufacturers have already submitted their label changes to the Food and Drug Administration (FDA) for approval. As manufacturers transition labels to the new USP standard, products with both the old and new labels will be available for use. This transition period presents potential for confusion and errors. For more information, go to www.usp.org and search “heparin label changes,” or to http://www.usp.org/usp-healthcare-professionals/medication-safety-labeling/heparin-labeling-changes.