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  1. Medical Countermeasures Initiative (MCMi)

Expiration Dating Extension

Pill bottles

To help prepare for public health emergencies, medical countermeasures (MCMs) may be stockpiled by governments and even by some private sector partners.

For example, the U.S. Department of Health and Human Services (HHS)  Assistant Secretary for Preparedness and Response (ASPR) oversees the Strategic National Stockpile (SNS), which has large quantities of medicine and medical supplies to protect the American public if there is a public health emergency (for example, a terrorist attack, flu outbreak, or earthquake) severe enough to cause local medical supplies to run out.  Some state and local governments and private sector entities also stockpile MCMs to have ready access to them if an emergency were to occur. 

A medical product is typically labeled by the manufacturer with an expiration date.  This reflects the time period during which the product is expected to remain stable, or retain its identity, strength, quality, and purity, when it is properly stored according to its labeled storage conditions.  Expiration dating can present challenges to MCM stockpilers because MCMs that have reached their labeled expiration date in most cases cannot be used.  While this is important to ensure patient safety, it also means that the MCMs, some of which might still be stable, must be replaced regularly, which can be very costly. 

In some cases, testing has shown that certain properly stored medical products can be used beyond their labeled expiration date if they retain their stability.  Recognizing stakeholders’ MCM stockpiling challenges, FDA is engaged, when appropriate, in various expiration dating extension activities as described below. 

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Approaches to Drug Product Expiration Date Extensions

Initiated by the Manufacturer

The manufacturer of an approved drug product may extend the expiration date for the drug product based on acceptable data from full, long-term stability studies on at least three pilot or production batches in accordance with a protocol approved in the NDA or ANDA. For additional information, consult the Guidance for Government Public Health and Emergency Response Stakeholders: Extending Expiration Dates of Doxycycline Tablets and Capsules in Strategic Stockpiles, page 3, or Guidance for Industry: Changes to an Approved NDA or ANDA.

Shelf-Life Extension Program

Stockpiling drugs, vaccines, and medical products is critical to ensure public health emergency preparedness for both the U.S. military and civilian populations.  To avoid the need to replace entire stockpiles every few years at significant expense, and because it was recognized through testing that certain products remained stable beyond their labeled expiration dates when properly stored, the Shelf-Life Extension Program (SLEP) was established in 1986.

SLEP is the federal, fee-for-service program through which the labeled shelf life of certain federally stockpiled medical materiel (e.g., in the SNS) can be extended after select products undergo periodic stability testing conducted by FDA. The program is administered by the U.S. Department of Defense (DoD). Through expiration dating extensions, SLEP helps to defer the replacement costs of certain products in critical federal stockpiles.  Program participants are U.S. Federal agencies that sign a Memorandum of Agreement with the Department of Defense, and SLEP remains limited to federal stockpiles at this time.

Primarily FDA-approved prescription drug (not biological) products are nominated by program participants as SLEP candidates. Current testing focuses on military-significant or contingency use products, drugs that have limited commercial use (e.g., nerve agent antidotes), and drugs that are purchased in very large quantities, such as ciprofloxacin and doxycycline.

FDA’s Office of Regulatory Affairs (ORA) Field Science Laboratories centrally manages the program, including interacting with DoD and coordinating laboratory work. The FDA Center for Drug Evaluation and Research (CDER) Division of Product Quality Research analyzes the data and makes decisions regarding shelf life extensions. The Office of Counterterrorism and Emerging Threats (OCET) collaborates with FDA Centers and federal partners to facilitate access to MCMs. This includes working to ensure that MCM-related policy supports programs like SLEP.

Emergency Use Authorities (including stockpiler-initiated)

In addition to SLEP, there are other ways that, when appropriate, FDA can allow certain medical products to be used beyond their manufacturer-labeled expiration dates. 

One way is through issuing an Emergency Use Authorization (EUA) under section 564 of the FD&C Act since use of a product beyond its labeled expiry date is considered unapproved.  However, before FDA can issue an EUA, a specific type of determination must be in place, the HHS Secretary must issue a declaration to justify the issuance of the EUA, the section 564 statutory criteria for issuing an EUA must be met, and FDA must determine that it is safe to use the product beyond its labeled expiration date.  This authority is limited to medical products for CBRN emergencies.

Another way FDA can approach expiration dating challenges is through FDA’s expiration dating extension authority under section 564A(b) of the FD&C Act, which was established by PAHPRA in 2013.  Before PAHPRA, the distribution, dispensing, or use of products with extended expiry, and any related labeling adjustments, were possible through an EUA or FDA enforcement discretion.  PAHPRA provides FDA with the explicit authority to extend the expiration dating of eligible FDA-approved MCMs stockpiled for use in CBRN emergencies. In addition to the identification of specific lots, batches, or other units covered and the duration of the extension, FDA can require appropriate conditions related to any extensions under this authority, including appropriate storage, sampling, recordkeeping, periodic testing or retesting, product disposition, and labeling. 

Enforcement Discretion

If appropriate, FDA can also choose to not take enforcement action with respect to products that are held or used beyond their labeled expiration date.  However, when enforcement discretion is used for medical product dating extensions, MCMs are not covered under applicable Public Readiness and Emergency Preparedness (PREP) Act liability protections.

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MCM Expiration Dating Extensions 

FDA acknowledges the stockpiling challenges of federal and SLTT stakeholders (for example, related to doxycycline, ciprofloxacin, Tamiflu, and certain auto-injector products) and remains committed to finding appropriate solutions to address such challenges.  Following are several examples of how FDA has addressed expiry dating challenges following PAHPRA’s enactment and before PAHPRA:


  • January 17, 2013: Before PAHPRA, in addition to FDA’s June 2010 letter below, a CDC message to states in 2013 regarding spot shortages of Tamiflu for seasonal influenza noted that, “…[b]ased on FDA’s review of scientific data, FDA has concluded that, provided the products have been stored under labeled storage conditions, it is scientifically supportable for certain lots of Tamiflu capsules held in strategic stockpiles to be used for a maximum of ten [10] years beyond their date of manufacture…” 

  • June 22, 2010: Before PAHPRA, following the 2009-2010 H1N1 influenza response, FDA issued a letter [ARCHIVED] to CDC leadership regarding the disposition of Tamiflu and Relenza lots. The letter noted that, based on FDA-approved supplemental New Drug Applications for Relenza inhalation powder and Tamiflu capsules that provided an expiration dating period of 7 years, it would be scientifically supportable for the expiry extension (i.e., for a maximum of 7 years) to apply to certain lots of Tamiflu and Relenza that have already been manufactured. FDA also recommended relabeling of such product prior to dispensing. More information  


April 2019 guidance: Extending Expiration Dates of Stockpiled Doxycycline for Anthrax Preparedness

Expiration date extensions of certain lots of doxycycline hyclate

Nerve Agent Auto-Injectors

Potassium Iodide (KI)

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Additional Information

  • Drug Shortages - Drug shortages can occur for many reasons including manufacturing and quality problems, delays, and discontinuations. Manufacturers provide FDA most drug shortage information, and the agency works closely with them to prevent or reduce the impact of shortages. More information, including the FDA Drug Shortages Database.

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