Accessibility Statement

Animal Care and Use

Since our founding in 1876, Lilly has worked tirelessly to discover medicines that make life better. We’ve been pioneers behind major breakthroughs against some of the world’s most devastating diseases, and therefore understand that developing new medicines demands determination and long-term investment – often requiring years of laboratory research, followed by years of clinical trials.

Prior to the clinical trial phase, a critical and legally required part of the drug development process is known as “in vivo” studies conducted in animals. In these studies, potential new medicines are tested in animals to evaluate how the medicine functions in a living organism, as well as its safety profile. In biomedical research, animals have contributed to life-saving treatments in the areas of cancer, diabetes, vaccines, high blood pressure, and neurological disorders, just to name a few.

Research advances in human medicines have made life better for a countless numbers of people worldwide. However, at Lilly, we also recognize that we have a moral and ethical responsibility for the welfare of animals used in research, which is why we have strong policies and principles in place to ensure that all animal research conducted either by our employees or by third parties on our behalf is in line with our values.

Our Commitment to Responsible Animal Research 

At Lilly, we know we have both an ethical and a scientific responsibility toward animals used in research. That’s why we have adopted the “3 Rs” when it comes to our principles of animal care and use. The 3Rs are applied prior to the start of any study involving animal testing: 

Replacement: The replacement of animals with alternative non-animal methods including the application of in vitro (test tube) systems or in silico (computer based) systems.

Reduction: The reduction in the number of animals used by the application of good experimental design and the proper statistical methods

Refinement: The modification of experimental technique to eliminate or minimize pain or distress and enhancements in animal husbandry to improve overall well-being in their colony environment (e.g. environmental enrichment)

Our 3Rs Global Committee is charged with ensuring implementation of the 3Rs and providing 3Rs Awareness Training to all Lilly employees who are associated with animal research. Sharing of 3Rs information across all sites is highly encouraged.

Our Principles for the Ethical Treatment of Animals 

We recognize we have ethical and scientific obligations to ensure the appropriate and humane treatment of animals used in research, and we have systems in place to fulfill this obligation. Lilly has developed a global Animal Care and Use Procedure on Animal Care and Use that defines our standards and principles by which we conduct in vivo research. This procedure mandates the humane care and use of all animals used in research. Any animal research conducted at Lilly should be performed only after consideration of the 3Rs as described above. Once the 3Rs have been implemented, Lilly’s Animal Care and Use procedure state that animals used in research shall be treated humanely, with pain or distress eliminated or minimized.

Specifically, our Principles state: 

  • Living conditions for research animals must be appropriate for their species and contribute to their health and well-being. 

  • Personnel who care for animals or who conduct animal studies must be appropriately qualified for the proper care and use of animals in research. 

  • Studies involving animals must be designed and conducted in accordance with applicable country and local regulatory guidance and the following widely recognized principles of animal care and use: 

    • with due consideration of the study relevance to human health and the advancement of scientific knowledge, 

    • selecting only animals appropriate for that study, 

    • using the minimum number of animals required to obtain valid results, 

    • using alternative methods instead of live animals where appropriate, and 

    • avoiding or minimizing discomfort and distress to the animals. 

Implementing these principles has resulted in increased awareness of the importance of quality animal care and use globally. The global procedure and principles have been supplemented by further standards specific to in vivo research.

Lilly Animal Care and Use Ethical Committees 

We maintain animal sites in the United States. All sites have oversight committees that approve and oversee animal research activities and care programs and ensure that people using animals are appropriately qualified. Committee members undergo intense and continuing training and all committees have volunteer members who are not affiliated with our company to represent the public. Veterinarians and scientists evaluate every procedure in an effort to eliminate or minimize pain or distress. Committees normally meet monthly to review animal use protocols and to conduct program or facility reviews as appropriate. These Committees also regularly recognize scientists who have demonstrated creative or improved novel methods for working with animals or who have demonstrated exceptional dedication in their work with animals.

Our Compliance with Global Animal Research Regulations and Standards

Consistent with our commitment to the responsible and ethical treatment of animals, we maintain the highest standards of animal care and we strive to demonstrate best practices in animal research. Lilly requires its R&D staff to comply with all applicable country and local laws, regulations, codes of conduct and standards regarding the care and use of animals. We require the same of all individuals and organizations that supply animals to be used in Lilly research, and with which Lilly contracts for animal research services. Moreover, we require application of the Lilly Animal Care and Use Principles by Lilly researchers and contractors, even if these principles are more stringent than applicable local laws. 

Our policy and standards regarding the use of animals are based upon the Animal Welfare Act and the Guide for the Care and Use of Laboratory Animals.

Inspections and Accreditation 

Lilly is accredited by AAALAC International, which provides independent review and confirmation of appropriate animal care and use.

We self-inspect our animal research programs and facilities regularly, including annual program reviews and semi-annual facility reviews. In situations where we have recently acquired another company, we work closely with that group to ensure that animal welfare standards align with our policy and principles. We also maintain a global oversight program of all animal research and supply companies with which we do business – including visits by trained specialists to conduct welfare evaluations – and encourage these companies to obtain and maintain accreditation from AAALAC International.

Fulfilling Our Commitment to the Ethical Treatment of Animals


All Lilly employees handling or working with animals in research must be appropriately trained and qualified in the care, use and welfare of animals to ensure that they are competent, that they are aware of humane and ethical issues, and that they demonstrate respect for all research animals. Training consists of modules including regulations, general husbandry and handling of various species, as well as individual training on a wide variety of procedures including anesthesia and surgery. New trainees are mentored and monitored for competency.

Animal Care 

Caretakers ensure animals are socially housed unless otherwise justified. Environmental enrichment for all species is required and monitored by the animal care staff. 

Contract Research Organizations 

Like most pharmaceutical organizations, the company outsources some research including various in vivo studies to contract research organizations (CROs). All CROs are required to adhere to our policy and principles thorough an assessment and monitoring program. Audits of CROs are conducted, and CROs are reassessed on a regular basis. These audits include all animal suppliers, feed vendors, and collaborations as well as those supplying research services. Moreover, we require contractors to adhere to the Lilly Animal Care and Use Principles, even if these principles are more stringent than applicable local laws. Lilly also encourages animal research and animal supply companies globally to obtain and maintain accreditation from AAALAC International.


The company participates and collaborates with a variety of national and international organizations whose mission is to promote quality research animal care and/or the development and use of the 3Rs including alternatives or replacement. Nationally, we participate in the Innovation and Quality (IQ) Consortium of PhRMA which has a strong 3Rs working group. We also participate in or collaborate with AALAS, ACLAM, ASLAP, PRIM&R, CAAT and AAALAC International. Internationally we have associations and supporting roles with EFPIA, FELASA, and NC3Rs among others. These interactions help keep our company current on alternatives and methods to implement the 3Rs.

Animal Numbers 

Lilly is committed to minimize the number of animals used in research studies. The majority of animals used in research are rodents; these are usually the most appropriate species because there are many strains of genetically engineered rodents that have been developed as specific models of disease. Other species are used when the disease target is more appropriately expressed in that particular species. Non-rodent models are also required by regulatory agencies for safety assessment. As a percentage of research and development (R&D) expenses, the number of animals used has decreased significantly in the past 25 to 30 years. We utilize organoids and other microphysiologic systems as research tools when appropriate. As new technology and methods merge that allow the use of less sentient species, we reduce our reliance upon the use of live animals and expect those numbers to continue to decline.

Nonhuman Primates 

Lilly acknowledges the specific concern by the public over the use of nonhuman primates in research. Our current policy dictates that careful consideration is given before any nonhuman primate species is used in research. Special consideration is given to nonhuman primate housing and their social/behavioral requirements. No species of primate that is classified as endangered may be used and the source of animals should be colony-bred and not wild-caught. Nonhuman primates must be obtained from reputable suppliers in compliance with all local, federal, and international regulations. 

Animals in Marketing 

Our commitment to respect for animals also applies to animals used in advertising by Lilly. All animals used must be healthy and handled by qualified people or owners. Animals must be in a natural or appropriate setting. 

Institutional Officials Consortium (IOC)

Lilly has a long history of supporting and maintaining membership of the IOC. This collaboration with other industry leaders helps ensure we stay abreast of current initiatives. Please visit the IOC website to learn more about the mission and vision of this collaboration.

Abbreviations and References

AAALAC International
AAALAC International is a private, nonprofit organization that promotes the humane treatment of animals in science through voluntary accreditation and assessment programs.
American Association of Laboratory Animal Science
American College of Laboratory Animal Medicine. Ag Guide: 2010. Federation of Animal Science Societies (FASS), 2010. Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching, third ed. FASS, Savoy. Champaign, IL
American Society of Laboratory Animal Practitioners.
  1. Animal Welfare Act. PL (Public Law) 89-544
Center for Alternatives in Animal Testing
European Federation of Pharmaceutical Industries and Associates
Federation of European Laboratory Animal Science Associations
ILAR Guide
National Research Council, 2011. Guide for the Care and Use of Laboratory Animals, eighth ed. National Academy Press, Washington, D.C.
National Center for 3Rs.
Public Responsibility in Medicine and Research.
The 3Rs
Russell, W.M.S. & Burch, R.L. (1959). The Principles of Humane Experimental Technique. xiv + 238pp. London, UK: Methuen