Animal testing has long been a cornerstone of scientific research, serving as a method to understand biological processes, test the safety and efficacy of products, and develop medical treatments. It involves the use of live animals in experiments and observational studies to explore the effects of drugs, chemicals, and other substances on biological systems. This practice, while often viewed as essential, is fraught with controversy, ethical dilemmas, and scientific scrutiny.

The origins of animal testing can be traced back to ancient Greece, where philosophers like Aristotle and Erasistratus conducted rudimentary experiments on animals to study anatomy and physiology. Over centuries, as medicine and technology advanced, the scope and complexity of animal testing expanded. By the 19th and 20th centuries, animal experimentation had become an institutionalized component of biomedical research, contributing to groundbreaking discoveries such as vaccines, antibiotics, and surgical techniques.

Today, animal testing is pervasive across multiple industries, including pharmaceuticals, cosmetics, and chemicals. It is primarily used to evaluate the safety of products, ensure regulatory compliance, and develop new treatments for diseases. Animals such as mice, rats, rabbits, and primates are commonly employed because of their physiological similarities to humans, which researchers argue make them suitable models for studying human biology.