USP Reference Standards Tables

The monthly USP RS Tables updates provide information on:

• Upcoming New RS Releases
• New RS’s Released in the Previous Month
• New Current Lots Released in the Previous Month
• RS’s Previously Out of Stock with New Lots Released in the Previous Month
• Backorder Availability Report (Estimates are as of the day the Table was created, refer to USP Store for up-to-date estimated availability dates)
• Changes made to the RS Description in the Previous Month, including but not limited to the Package Size and the Discontinuation of an RS
• Lots having Valid Use Dates in the Previous, Current, and Upcoming Months 

Note: These tables are a summary only. Visit the USP Store for complete and up-to-date information. 

Contact Reference Standards Technical Services at rstech@usp.org if you have any questions about the RS Tables and their content. 

Latest Reference Standards Tables

• May 2025