How better ways of screening drugs could soon lead to thousands fewer animal tests

As many as 190 million animals are used in biomedical research around the world every year. But after centuries of experiments, controversy and countless life-saving benefits, science may finally be approaching a point where animal testing is no longer the default option. Until recently, that idea would have sounded implausible.

Modern biomedical research has relied on animals almost since its inception, using them to study disease and test new medicines before they ever reach people. But over the past few years, that assumption has begun to shift. Efforts to replace animals in science have the firmest backing yet from policy-makers and regulators.

In April 2025, the US Food and Drug Administration (FDA) published a five-year road map to reduce animal testing in drug-safety studies. Months later, the country’s National Institutes of Health (NIH) stopped requiring animal models for many of its grants. Late last year, the UK launched a similar plan to phase out animal testing, and the European Union followed suit in June.

We may finally have a cure for many different autoimmune conditions These initiatives largely seek to make more widespread use of better alternative methods. A sliver of plastic no bigger than a microscope slide threaded with human liver cells can now identify toxic drug effects better than using rats. Lab-grown cells are sparing rabbits from once-indispensable tests that screen medicines for contaminants.

And AI models are identifying potential drug targets at record speeds, without using animals. Animal experimentation dates at least as far back as the ancient Greek philosopher Aristotle, who dissected dozens of animal species to better understand anatomy. But modern systematic use of animal experiments didn’t start until the mid-1800s.

Then, and now, advocates for using animals argued that many of them have bodies similar enough to humans to justify tests on biological mechanisms and drug effects, thus informing science and improving healthcare without injuring people. Pushback started almost immediately. Public horror at some of the Victorian physiologists’ methods prompted the UK to pass the world’s first animal testing law in 1876, which ensured it was done only by licensed scientists.