Don't we NEED animal testing for medicine?

The objection

“Be honest, without animal testing, we’d have no medicine. People would die. You can’t be against that.”

The answer

Take the strongest version first, because the easy version is wrong. Animal research has contributed to real medical advances over the last century, and pretending otherwise would be dishonest. The serious question is not whether it ever helped but whether it’s a good predictor of what happens in a human body. Increasingly, the answer is no.

Species differ, and so does their biology. A compound can look safe and effective in a mouse and behave entirely differently in a person. The resulting translation failure has become notorious: more than 90% of drugs that pass animal testing go on to fail in human clinical trials, mostly for unexpected toxicity or simply not working. Peer-reviewed reviews put the rate above 92%, and it has barely shifted in decades (Marshall et al. 2023). Only around one in ten drugs entering human trials is ever approved. That is a lot of animals suffering to predict an answer the test keeps getting wrong.

Meanwhile the alternatives have arrived: human “organs-on-chips,” lab-grown organoids from human cells, and in-silico computer models that test against human biology directly rather than a stand-in species (Han 2023). They aren’t perfect either, but they’re built from the right starting material.

The clearest sign of the shift is legal. In December 2022 the US FDA Modernization Act 2.0 removed the decades-old requirement that every new drug be tested on animals first, explicitly permitting these human-based methods instead (US Congress S.5002).

So “we need it” is sliding from fact into habit. The case for animal testing was always weakest at the one job that mattered, predicting humans, and the law has finally started to admit it.