For far too long, animals have been used in research and testing across the United States—often in painful, invasive experiments—even when superior, non-animal testing methods are available.  

This practice persists not because it produces better science, but because our laws have failed to keep pace with scientific innovation. That could finally change. 

In December 2025, Representatives Jared Moskowitz, Jan Schakowsky, and Shri Thanedar introduced the Replace Animal Tests Act of 2025 (Replace Act) (H.R. 6660), landmark legislation designed to modernize U.S. regulatory testing and significantly reduce the use of animals subjected to it. 

If enacted, the Replace Act would represent one of the most meaningful federal advances for animals in laboratories in years. 

Take Action: Support the Replace Act

What the Replace Act Would Do

At its core, the Replace Act establishes a clear, enforceable standard: when scientifically satisfactory non-animal test methods are available and accepted by regulators, animal tests must not be used instead. 

The Replace Act would: 

• Prohibit regulated entities from submitting animal test data to federal agencies when an approved non-animal method exists  
• Require agencies to issue guidance and update regulations to reflect the acceptability of non-animal testing methods 
• Reduce animal tests by limiting them to only certain circumstances  
• Mandate harm-reduction standards, including minimizing the numbers of animals used in tests
• Increase transparency and public accountability through annual reporting on animal use, species involved, testing purposes, and waivers granted

The law would apply to major federal agencies that oversee product safety and approval, including the FDA, EPA, USDA, and Consumer Product Safety Commission. 

In short: the Replace Act would stop animal tests from being the default. 

Why this Bill Is Important for Animals, Science, and People 

Despite enormous advances in human-relevant science—such as organ-on-a-chip technologies, computational models, and advanced human cell-based systems—animals are still used in regulatory testing out of habit, not necessity. 

This has real, devastating consequences for animals, millions of whom endure confinement, pain, distress, and death in tests that often fail to accurately predict human outcomes. Meanwhile, non-animal methods are more ethical and more directly relevant to human biology.  

The Replace Act recognizes a simple truth: good science and animal protection are not in conflict. Rather, they go hand-in-hand. 

The bill would also bring the U.S. closer to international standards already in place in the European Union and United Kingdom, as well as policies already adopted in several U.S. states. And it aligns with shifting public values: today, more Americans are saying “no” to animal research than ever before. 

As Rep. Moskowitz said: 

“For too long, animal tests have continued not because they’re necessary, but because our rules haven’t kept pace with modern science. No animal should have to suffer simply because our regulations haven’t caught up with the science.” 

Your Call to Action 

Strong legislation doesn’t move through Congress on its own, particularly when it challenges entrenched practices and industry inertia. Lawmakers need to hear from constituents that this issue matters, and that ethics, modernization, and better science should guide federal policy. That’s where you come in. 

A minute of your time can help spare countless animals from unnecessary suffering—and help move science forward, for all of us.

We’ve made it easy for you to take action by providing a letter you can send directly to your Representative, urging them to support H.R. 6660.  

Send a Letter to Your Representative

Share this letter campaign on X, Bluesky, or Facebook.
Or copy, paste, and share this link anywhere:
actionnetwork.org/letters/replace-act