5 technologies that are replacing animal testing.

For decades, animals have been subjected to painful and traumatising experiments in the name of science — despite clear evidence that animal testing consistently fails to predict what will happen in humans.

Across most areas of biomedical research, treatments that appear effective in animals frequently do not work in people. In fact, 90 – 95% of experimental drugs that pass animal tests fail in human trials. That’s because an animal’s biology, disease processes, and responses to drugs differ in important ways from our own. Animal experiments often cannot answer the very questions they are used to justify — how a disease develops in humans, or whether a treatment will be safe and effective for patients.

And the cost of these failures is profound — both for the animals and for the human patients left waiting for real medical breakthroughs.

The good news is, a quiet revolution is underway.

Around the world, scientists are developing powerful new tools that study human biology directly — without harming animals. Known collectively as New Approach Methodologies (NAMs), these innovations are already reshaping drug development, chemical safety testing and disease research.

They offer something profoundly important: better science that doesn’t come at the cost of animal suffering.

Here are five of the most promising technologies leading this shift.

Instead of experimenting on animals, researchers can work with living human cells grown in laboratories.

Using advanced 3D techniques, scientists can create organoids — tiny, self-organising clusters of human cells that mimic key features of real human organs, such as livers, lungs or even parts of the brain.

This can replace the widespread practice of creating human diseases in animals — who do not naturally suffer from them — to explore potential treatments.

Why this is a game-changer

Human cell models are often more accurate, faster and more relevant than animal experiments — and they spare animals from invasive procedures entirely.

An organ-on-a-chip is a small, clear plastic chip with tiny channels that allow fluid to flow, similar to blood moving through the body. Human cells grow inside these channels, allowing scientists to observe how human tissues behave and respond to substances under realistic, flowing conditions. Some systems can even mimic dynamic processes such as breathing movements or digestion.

By connecting different chips — for example, linking a liver chip with a heart, brain, or immune chip — researchers can study how a drug or chemical moves through the human body and how it affects multiple organs over time.

These systems are particularly valuable because in many fields, especially those involving complex human biology, such as the immune system, animal models are poor predictors of safety and effectiveness. A few practical applications for organ-on-chip technologies include:

• Immune-system-on-a-chip platforms which allow researchers to study human immune responses directly, something animal models cannot reliably do because immune systems differ fundamentally between species.
• Blood–brain-barrier-on-a-chip systems that recreate the tightly controlled barrier that protects the human brain — a structure that varies significantly across species and has long limited the usefulness of animal testing in neurological research.
• Cervix-on-a-chip models which can replicate the unique structure, hormonal regulation, and immune environment of human reproductive tissues — features that cannot be reliably studied in animals. This is opening new possibilities in women’s reproductive health, an area that has historically been under-researched.

Until now, researchers have tried to obtain this kind of information by repeatedly dosing animals such as mice, rats, or dogs with toxic substances and observing signs of harm. However, because animals and humans often respond very differently to the same substance, these tests consistently fail to predict real human outcomes.

Why this is a game-changer

Organs-on-chips can reveal harmful human-relevant side effects earlier and more reliably by focusing directly on human biology rather than testing in animals. By identifying safety problems sooner, these systems help researchers stop ineffective or unsafe drugs earlier in development — reducing costly late-stage drug failures.

Powerful computer models and artificial intelligence can analyse enormous datasets to predict how drugs and chemicals behave in people — without testing on other living beings.

While many current AI models still draw partly on historical animal data, they increasingly rely on human-derived information from clinical studies, human cell systems, and real-world evidence. The aim is not to recreate animal results on a computer, but to replace animal data altogether by building models grounded in human biology.

A major scientific review published in 2025 found that AI-based non-animal methods already match or outperform animal experiments in key areas such as reliability, scalability, and relevance to human health. Unlike animal tests, AI models can be updated continuously as new data emerge, rather than relying on fixed experiments that often fail to translate to people.

This is no longer a future promise. Regulators are actively developing frameworks to evaluate and validate AI-based methods, and falling computing costs are accelerating their adoption.

Why this is a game-changer

AI-driven models speed up research, reduce animal use, and deliver results that are more relevant to human health.

Safety testing does not require animals to be effective.

In in chemico testing, scientists study how a chemical behaves at the most basic biological level — by examining its interactions with molecules that are already known to be harmful. For example, researchers can test whether a chemical reacts with or binds to proteins in ways that are linked to skin irritation, allergic reactions, or other toxic effects in humans.

This approach works because many harmful effects follow well-understood chemical rules. Certain types of molecular reactions are known to damage cells or trigger inflammation, regardless of species. By focusing on these mechanisms directly, scientists can assess danger without observing suffering.

So, instead of applying chemicals to an animal’s skin or eyes or force-feeding them toxic substances to see when harm occurs, in chemico tests examine the chemical itself under controlled laboratory conditions. The results are then used to predict whether a substance is likely to cause harm in people.

These methods are already used internationally in areas such as cosmetic and chemical safety testing, where animal testing has been restricted or banned.

Why this is a game-changer

In chemico methods eliminate animal use entirely while producing clearer, more precise safety information.

The most exciting advances combine multiple non-animal tools — human cells, computer models, and molecular data — into integrated testing systems.

These platforms allow scientists to build a complete picture of safety and risk without defaulting to animal experiments at every stage.

Where entire research pipelines once depended on repeated animal testing, these approaches show that robust safety assessment can be achieved without animals at the centre.

Regulators in several countries are now actively encouraging these methods, recognising that they are more relevant to human biology than animal tests.

Why this is a game-changer

This is not a small tweak to the system — it is a re-imagining of how science works, grounded in human biology and ethical responsibility.

For generations, animal testing has been framed as “necessary”. But the evidence tells a very different story: holding onto animal experimentation is holding back medical progress.

Animal experiments are harmful on multiple levels. To the animals stuck in cycles of testing for their entire lives. To the humans working within these systems who carry the emotional burden of harming animals as part of their daily work. And to the patients who are left waiting for treatments and cures that never come.

At the same time, human-relevant research methods, grounded in human biology, are showing that science without animals can advance faster, more reliably, and more ethically.

This is science evolving — toward practices that improve human health and wellbeing and respect other living beings.