Which drug company does the most animal testing?
Executive summary
There is no publicly verifiable “most animal testing” drug company because companies and regulators do not publish comparable, centralized totals of animals used across jurisdictions and research types, and third‑party lists name firms that test but not volumes [1] [2]. Analysis of available reporting suggests the largest users are simply the largest R&D spenders—big human‑pharma R&D houses and global animal‑health firms—while regulatory moves and investment in non‑animal methods are actively changing the landscape [3] [4] [5] [6] [7].
1. What the question is really asking — animals, counts, and metrics
As phrased, the question seeks a quantitative ranking (which company uses the most animals), but meaningful answers require defining metrics (number of animals, species mix, tests performed, or pounds of animal tissue), data sources and geography; global market research and reviews make clear animal testing spans mice, rats, rabbits, dogs, primates and more, and different industries and countries report in different ways, so simple head‑to‑head comparisons are not available without standardized reporting [8].
2. Why there is no public leaderboard — disclosure and data gaps
Public reporting is fragmented: animal‑welfare groups publish lists of companies that test (PETA’s lists, summarized by cruelty‑free sites), but these identify practices and associations rather than volumes, and corporate transparency pages describe policies and welfare commitments without tabulating global animal counts across all labs and contract research organizations [1] [2].
3. Who the likely top users are — scale, R&D intensity and animal health firms
Reasonable inference points to the biggest drug and animal‑health R&D organizations as the largest users: legacy pharmaceutical companies with massive pipelines publicly describe extensive in‑vivo programs (for example, Novartis’ animal research pages explain ongoing programs and welfare commitments) and global animal‑health firms such as Zoetis, Merck Animal Health, Boehringer Ingelheim and Elanco dominate markets that inherently involve large animal studies for vaccines and veterinary medicines [3] [5] [4] [9].
4. Why animal‑health companies matter separately
Animal‑health companies both develop medicines for livestock and companion animals and therefore run field trials and laboratory studies on target species at scales that human‑pharma generally does not; industry rankings list Zoetis and Merck Animal Health among the largest players globally, indicating they likely account for a major share of non‑human laboratory and clinical animal use even as their studies differ from preclinical human drug testing [5] [9].
5. The shifting baseline — regulation, alternatives and commitments
Regulatory change and technology are changing who uses animals and how often: the FDA and advocates are actively promoting a roadmap to reduce animal testing in preclinical safety studies, and industry analyses expect in‑vitro, organ‑on‑chip and in‑silico methods to displace some in‑vivo work over the next five to ten years—meaning that current volume estimates are a moving target [7] [6].
6. Balancing perspectives and hidden incentives
Animal‑welfare NGOs publish company lists to drive consumer pressure, which identifies culpability but not scale, while companies emphasize welfare standards and 3R (replace, reduce, refine) investments; both perspectives have agendas—NGOs push for elimination, firms for reputational and regulatory compliance—so neither side alone answers “who does the most” without independent, standardized numbers [1] [3] [10].
7. Bottom line: no single company can be credibly named from available reporting
Given the fragmented public data, the best supported conclusion is that the largest R&D spenders in human and animal pharmaceuticals are the likeliest largest users of animal testing, but available sources do not provide a verifiable, ranked total to name a single company as definitively “doing the most” [3] [5] [1] [8].