Alternatives and NAMs

Recent NIH Announcements

I’m Curious About...

• What NAMs are and how does OLAW fit into NAMs use? "See the What are NAMs?" section below
• What NIH is doing in the NAMs space? Check out the Complement-ARIE program and NIH's Standardized Organoid Modeling (SOM) Center! NIH is also a part of the interagency committee ICCVAM.
• What IACUCs are responsible for when it comes to NAMs? See the "Tips for Investigators and IACUCs" section below.
• Who oversees NAMs in grants and contracts? As OLAW provides guidance regarding the administration of the PHS Policy, which applies to live, vertebrate animal use, questions regarding NAMs in grants and contracts should be directed to individual Institutes and Centers.
• Where can I find NAMs funding or training? Check out the "Resources for Investigators and IACUCs" section under Quick References below.
• How do I make a media inquiry regarding NAMs at NIH? Visit the NIH Grants and Funding Information for Media and the Public webpage for contact information.    

Quick References

External resources are provided as a courtesy and their listing does not imply content control or endorsement by NIH. Please email suggested resources to the OLAW Division of Policy and Education at [email protected]. Commercial entities are not eligible for listing.

Resources for Investigators and IACUCs

Funding Opportunities Involving NAMs:

• NIH Funding: As of July 7, 2025, NIH will no longer issue Notices of Funding Opportuntities (NOFOs) exclusively supporting animal models or limit/specify the types of models that must be used. The intent of this effort is to ensure investigators consider the models most appropriate for understanding human states of health and disease and are not constrained by the NOFO. NIH will continue to support grants that use laboratory animal models if scientifically appropriate, justifiable, and with proper animal welfare oversight. You can find a list of current NIH funding opportunities here: Search for NIH Funding Opportunities.

  See also: Updates to Finding NIH Funding Opportunities and Information, How Does the NIH Initiative to Prioritize Human-Based Research Affect Research Proposing the Use of Laboratory Animals?, and NIH Funding Announcements to Align with NIH Initiative to Prioritize Human-based Research.
• Complement-ARIE Funding Opportunities page
• FNIH Call for NAMs Pilot Projects
• National Agricultural Library's 3Rs Funding Opportunities list

Literature Search Resources

• USDA Animal Welfare Information Center (AWIC) Resources for Alternatives Literature Searching
• National Toxicology Program Interagency Center for the Evaluation of Alternative Toxocological Methods (NICEATM) ALTBIB- Alternatives to Animal Testing literature search tool
• NORECOPA PREPARE Guidelines

Education and Training:

• NIH Standardized Organoid Modeling (SOM) Center
• NIH When Are Alternatives to Animals Used in Research webpage
• USDA AWIC Animal Use Alternatives webpage
• Annual 3Rs Symposium: Presentations on cutting-edge research involving NAMs and the 3Rs, as well as discussion of practical strategies for implementation. Be sure to register for the current year symposium! You can also access past symposia on the USDA National Agricultural Library's Animal Use Alternatives website.
• EPA New Approach Methods: Efforts to Reduce Use of Vertebrate Animals in Chemical Testing
• EPA Catalog of NAMS Training Materials
• EPA NAMs Conferences
• FDA Advancing Alternative Methods at FDA
• The 3Rs Collaborative
• The 3Rs Collaborative Species-Specific Refinement Resources
• NC3Rs
• NICEATM Alternative Methods resources
• NORECOPA 3Rs Resources
• RE-Place: Alternative Methods to Animal Testing resources
• USDA AWIC alternatives workshops (live and on-demand)
• NICEATM and ICCVAM Meetings, Workshops, and Webinars
• Johns Hopkins University Center for Alternatives to Animal Testing
• Society of Environmental Toxicology and Chemistry (SETAC) New Approach Methodologies

Selected Workshops from the National Academies of Science (NAS):

• New Approach Methods (NAMs) for Human Health Risk Assessment | Workshop 2 (May 12, 2022)
• New Approach Methods (NAMs) for Human Health Risk Assessment | Workshop 1 (December 9, 2021
• Microphysiological Systems: Bridging Human and Animal Research - A Workshop (January 19-20, 2021)

Resources for Students and the Public:

You can learn more about how the NIH approaches animal use and NAMs by visiting the NIH Animals in Research web series. These pages discuss why animals are used in research, how animals have helped improve public health, how NIH ensures the care of animals used in research, when alternatives are used in research, and more!

Visit the NIH's Complement Animal Research In Experimentation (Complement-ARIE) Program webpage to learn about current initiatives to promote alternatives. The Interagency Coordinating Committee on the Validation of Alternative Methods (ICCVAM) is also a part of the NIH's National Institute of Environmental Health Sciences (NIEHS). 

• NIH Animals in NIH Research page
• Complement Animal Research In Experimentation (Complement-ARIE) Program
• About ICCVAM

Tips for Investigators and IACUCs

While the concept of seeking alternatives is not new, recent advances in technology have made them more available than ever before! Here are some tips and reminders of existing guidance to help you as you think about how alternatives can be incorporated into your work or the work at your institution. Remember that "alternatives" can include strategies that reduce animal use overall, improve animal welfare over an existing practice, or in some cases serve as a complete replacement for animals.

For Investigators

For IACUCs

What are NAMs?

The 3Rs: Replacement, Reduction, and Refinement

The methods featured on this page fall into the categories of in vitro, in chemico, or in silico models. These involve testing methods that utilize human tissues, microphysiological systems (MPS), benchtop laboratory equipment, computer simulations, artificial intelligence (AI), or similar approaches to explore scientific questions without the use of a living organism. Some approaches, called "combinatorial" approaches, utilize multiple methods. "NAMs" is an acronym that serves as an umbrella of many similar terms for these same concepts. Some of the various definitions across agencies and nongovernmental groups have included:

• New Approach Methodologies
• Non-Animal Models
• Novel Alternative Methods

...and many more! 

The U.S. Government Principles, which are incorporated into the PHS Policy, state that "[p]rocedures involving animals should be designed and performed with due consideration of their relevance to human or animal health, the advancement of knowledge, or the good of society." (Principle II) Further, they clarify that "[t]he animals selected for a procedure should be of an appropriate species and quality and the minimum number required to obtain valid results. Methods such as mathematical models, computer simulation, and in vitro biological systems should be considered." (Principle III) The use of alternatives in translatable research, where scientifically appropriate, has been a core principle of animal use for a long time. The consideration of alternatives to replace animal models is one of three core principles of responsible animal use called the 3Rs. They include:

• Replacement: Use of alternatives to animal models
• Reduction: Use of methods that allow for fewer animals to be used.
• Refinement: Use of methods that improve animal welfare by minimizing pain and distress

The concepts underlying these 3Rs have been incorporated into the Guide for the Care and Use of Laboratory Animals (first published with NIH support in 1963) and the PHS Policy from the earliest stages. Sometimes "NAMs" is used interchangeably with the term "alternatives" in the context of complete replacement of an animal model. However, it is important to remember that NAMs are not the only alternatives in biomedical research. Alternatives that reduce animal use, refine established procedures, and elevate animal welfare in existing practices are also part of responsible animal use.

While not every scientific question can be answered by using NAMs, these new technologies can be very useful in some specific applications. In a press release on July 18, 2025, NIH noted that " [r]esearchers may choose any model they deem appropriate – including a combination of approaches – to answer a research question when submitting applications seeking NIH support. This strategy is intended to open the possibilities of which types of models can be submitted in response to funding opportunities, not be restrictive or prescriptive." Regardless of the method used, whether in vivo or not, it is important that the research method be appropriate and yield relevant, translatable, and reproducible results. Fit-for-purpose use of NAMs is also in keeping with mandate in the U.S. Government Principles (Principle IV) that "[p]roper use of animals, including the avoidance or minimization of discomfort, distress, and pain when consistent with sound scientific practices, is imperative." The NIH Complement-ARIE Program is actively working to support the development and standardization of NAMs, and you can learn more about the initiative by clicking the button below:

Complement-ARIE