What are the 3R's?

Among its many areas of oversight, the IACUC Committee ensures that researchers are compliant with the USDA Animal Welfare Act, including USDA Policy 12. This policy requires that investigators consider alternatives to procedures that may cause more than momentary or slight pain, or distress to research animals.

The USDA considers the performance of database searches and analysis of articles as an effective method for demonstrating compliance with this requirement. 

Literature searches and corresponding narratives should address the 3R’s as discussed by Russell and Burch in their classic publication, The Principles of Humane Experimental Technique.


  1. Reduction—Minimize the number of animals used, without jeopardizing statistical validity
  2. Refinement—Employ techniques that reduce pain and distress
  3. Replacement—Substitute animals with non-animal methods (i.e., computer simulation) or lower animal species