An evidence-informed commentary on animal experimentation regulation and the development of alternative methods in six Latin American countries

Animal experimentation remains part of biomedical research, toxicology, agriculture, education, and product safety assessment in Latin America, while the development and implementation of alternative methods are advancing unevenly. Regulatory frameworks regarding animal use for experimentation differ across countries, and limited public reporting often prevents a clear understanding of the number of animals used, the species involved, and the procedures performed. This evidence-informed commentary examines the regulation of animal experimentation and the development of alternative methods in six Latin American countries where Te Protejo, a civil society organization, through its work in awareness raising, public policy and community engagement, has established institutional presence and regional experience: Chile, Argentina, Brazil, Colombia, Peru, and Mexico. It does not aim to provide a comprehensive review of Latin America as a whole or a quantitative inventory of animal use. Instead, it uses these six countries as illustrative cases, reviewing on legal and regulatory documents, institutional sources, published and grey literature, transparency requests where available, and Te Protejo’s experience in policy and regulatory discussions related to laboratory animal protection and alternative methods. The six countries examined show heterogeneous progress. Brazil and Mexico present comparatively more developed frameworks, including more specific regulatory instruments, reporting mechanisms, and institutional structures related to laboratory animal science and alternative methods. Chile, Colombia, Argentina, and Peru have also made relevant advances, including animal welfare laws, ethical review mechanisms, and bans or proposals concerning cosmetic animal testing, but continue to face important gaps in implementation, oversight, transparency, and harmonized reporting. Across the six countries, the absence or partial availability of centralized animal-use data limits robust assessment of species use, procedure numbers, and the distribution of animal experimentation across sectors. Available information, including data from Brazil and Mexico and partial evidence obtained through transparency requests in Chile, suggests that rodents are among the most frequently reported species. Alternative methods, including in vitro, computational, organoid, reconstructed tissue, and other replacement-oriented approaches, are emerging through academic, regulatory, commercial, and civil society initiatives, but their uptake remains uneven and often concentrated in isolated institutions or sectors. The six countries examined are at different stages of regulatory and scientific transition. Their shared challenges point to the need for stronger regulation, transparent reporting systems, clearer enforcement mechanisms, greater public access to animal-use data, and formal recognition and implementation of alternative methods. Improving regulation, transparency, and compliance in these countries would support more accountable animal research systems and create better conditions for the development and adoption of human-relevant, animal-free approaches.