Comparative assessment of animal experimentation regulations and the integration of new approach methodologies across six Latin American countries

This study provides a comprehensive analysis of the current landscape of animal experimentation in Latin America, examining regulatory frameworks, ethical standards, and the integration of new approach methodologies (NAMs) across six countries: Chile, Argentina, Brazil, Colombia, Peru, and Mexico. Despite heterogeneous progress, the region continues to rely heavily on animal models for biomedical research, toxicology, agriculture, and education, with rodents constituting most laboratory use, and wildlife frequently involved in ecological and productive research. While pioneering advances, such as the ban on cosmetic animal experimentation in Colombia, México, Chile and Brazil, signal regional improvement, regulatory gaps persist due to fragmented legislation, limited oversight, and the absence of centralized data on animal use. Institutional Animal Care and Use Committees (IACUCs/CICUALES for its Spanish acronym) exist but vary widely in effectiveness, largely depending on institutional commitment and training. At the same time, the expansion of NAMs including organoids, in vitro toxicity assays, and in silico or computational modeling, has begun reshaping scientific practices, supported by emerging specialized laboratories and civil society organizations. However, NAMs adoption remains uneven and concentrated in isolated academic or commercial initiatives. Findings highlight the urgent need for standardized regulations, transparent reporting systems, increased state oversight, and stronger regional collaboration to ensure ethical, scientifically robust, and humane research practices. Overall, Latin America stands at a transitional point, where the convergence of scientific innovation, public pressure, and ethical awareness offers a unique opportunity to modernize research systems and reduce reliance on animal experimentation.