Lauren Stein, Director of Science and Research Programs at the National Anti-Vivisection Society (NAVS), is helping advance the future of biomedical research through innovative, human-relevant technologies. Drawing on a decade of experience in academic research and a Ph.D. in Pharmacology and Physiology, she works to promote scientific methods that replace animal use while improving outcomes for human health. Through her work, Lauren highlights how emerging technologies are reshaping research and accelerating the transition toward more effective and humane science.
As awareness grows around animal testing, what do you see as the most significant cultural or ethical shift driving this change in scientific research?
The most significant shift is a fundamental change in how the scientific community defines good science. For a long time, using animals was not just accepted, it was considered the rigorous choice. The ethical question of whether we should use animals was largely separate from the scientific question of whether we needed to. What’s changed is that those two questions have merged. Scientists are increasingly asking both at once.
That didn’t happen overnight. The Three Rs (Refine, Reduce, Replace) were introduced in 1959, and by 1985, the AWA amendments had mandated IACUCs and made consideration of alternatives a federal funding requirement, so the ethical infrastructure has been in place for decades. What’s different now is that the science has finally caught up to the ethics. The accumulation of evidence supporting new approaches means scientists no longer must choose between rigorous and humane work. That’s the real shift: the ethical and scientific imperatives are now pointing in the same direction, and that alignment is what’s accelerating change in a way that advocacy alone never could.
We’re also seeing a genuine shift in values among younger scientists. They’re entering the field with both an efficacy and an ethical lens already integrated. What’s striking, though, is that many of them want to pursue NAMs but feel constrained by the system around them: reviewer expectations, publication pressure, funding structures that still favor animal-based designs. That gap between what the next generation wants to do and what the infrastructure currently rewards is actually one of the strongest arguments for the policy changes we’re seeing at NIH and FDA right now.
Despite increasing concerns, animal testing is still widely practiced. What are the main barriers preventing a faster transition to alternative methods?
The barriers are scientific, structural, and regulatory, and until recently, they’ve been mutually reinforcing. Decades of career investment in animal-based expertise, a funding and publication system biased toward animal models, and an FDA that historically required animal testing have all worked together to make the status quo extremely difficult to disrupt. What’s different now is that all three are being challenged at the same time.
The scientific barrier is inertia. Researchers spend entire careers building expertise around specific species and disease models, and the evidence base for NAMs, while growing rapidly, took time to accumulate. You can’t shift a field overnight when that field has decades of institutional knowledge invested in existing methods.
The structural barrier is arguably more stubborn. Grant review panels have historically favored animal-based designs, creating what researchers have called “animal-reliance bias,” scientists feeling compelled to include animal data just to get funded or published, even when it isn’t scientifically necessary. NIH is now training grant reviewers to address that bias directly, which tells you how deep it runs.
The regulatory barrier has been the most concrete. The FDA historically mandated animal testing for drug safety and efficacy, locking it into the entire drug development pipeline. The FDA Modernization Act 2.0 removed that mandate, and the FDA’s 2025 roadmap sets a goal of making animal testing the exception rather than the rule within three to five years.
From a scientific standpoint, what limitations exist in animal testing that make human-relevant alternatives more effective or reliable?
At its core, the problem is simple. Human biology is sufficiently distinct from that of other species that what happens in an animal model often doesn’t predict what happens in a human patient. No matter how carefully you design an experiment, you’re still studying a different species and hoping the results translate. Animals process drugs differently, mount different immune responses, and experience diseases differently than we do. A drug that looks safe and effective in a mouse may behave completely differently once it enters a human body. That’s not because the science was done poorly, but because biology is fundamentally different. Modeling human disease in non-human species can be incredibly problematic. While some species do develop pieces of the pathology, no animal naturally develops the full disease as humans experience it. Scientists have to engineer animals to approximate it, and those approximations have repeatedly failed to predict which treatments work in people. Simply put, a lab rat is not a tiny human. We’ve treated it as a useful stand-in for decades, but the data tells us it isn’t.
Can you share some of the most promising emerging alternatives that are helping replace animal use in research today?
Three technologies are really driving the shift right now: organ-on-a-chip, organoids, and AI. And what’s exciting is that we’re past the “this looks promising” stage. In some key areas, these tools are already outperforming what they’re replacing.
The one that’s gotten the most attention recently is organ-on-a-chip. The basic idea is that a tiny device about the size of a USB drive is lined with living human cells that actually behave the way they would inside your body. Think of a breathing lung, a beating heart, a metabolizing liver. Emulate’s Liver-Chip is a great example of where this is going. In a blinded study, it correctly identified 87% of drugs that caused liver injury in humans; some of these drugs had passed animal testing and gone on to harm patients. Animal models detected none of them. The FDA took notice, citing that data in its 2025 roadmap and accepting the chip into its formal regulatory qualification program. And now scientists are connecting multiple chips to model how different organ systems interact throughout the body. That’s when it really starts to look like a human body-on-a-chip.
Organoids are related but a bit different. Instead of engineered devices, these are miniature 3D tissue models grown from human stem cells. They self-organize into structures that resemble real organs. They’re especially useful for modeling diseases that don’t occur naturally in animals, and because you can grow them from a specific patient’s own cells, they’re a key part of where personalized medicine is headed.
Then there’s AI and computational modeling, which is moving incredibly fast. These tools can screen millions of drug candidates against thousands of targets, flag potential toxicity, and model how a compound will behave in the human body, all before a single experiment is run. What used to take years can now happen in a fraction of the time.
How is policy evolving to support the reduction or elimination of animal testing, and what role does advocacy play in accelerating the process?
The policy landscape has shifted more in the last three years than in the previous three decades, and it’s happened at every level simultaneously.
In 2022, the FDA’s Modernization Act 2.0 removed the legal mandate for animal testing. Then, in April 2025, the FDA went further, publishing a roadmap with a concrete goal: to make animal testing the exception rather than the rule within three to five years. At NIH, as of July 2025, proposals relying exclusively on animal data are no longer eligible for funding. These aren’t aspirational statements. They’re binding policy changes backed by the two largest funders and regulators of biomedical research in the world.
What’s driving these agencies isn’t ethics, it’s evidence. The FDA has cited the high clinical trial failure rate as a core rationale for the shift. They’re not moving away from animal testing because it’s unpopular. They’re moving away from it because the data shows it isn’t working well enough.
Advocacy didn’t create this shift; the science did. But what advocacy has done is accelerate the timeline and raise the urgency. By documenting the failures of animal models, amplifying the successes of NAMs, and mobilizing scientists to engage with regulatory processes, advocacy organizations have helped compress what might have taken another decade into a few years. In drug development, time translates directly into lives.
In your role at NAVS, how do you engage with the science and research community and institutions to encourage more humane research practices?
Our approach is not to demonize scientists who have done or continue to do animal research. That only alienates the scientific community, and we want to come to the table with them and meet them where they are.
In practice, that means focusing our resources on investigators who are genuinely excited about new approach methodologies and giving them the tools, funding, and support they need to succeed. Through our partnership with the International Foundation for Ethical Research, we fund graduate students developing NAMs-based research. Our goal is to develop the next generation of scientists and ensure they are NAM scientists from the start of their careers.
What we’re seeing at conferences reflects that this approach is working. Scientists are coming to us now, saying there are serious ethical concerns with animal research. You wouldn’t have heard that several years ago. And increasingly they want to be more involved by mentoring students, training the next generation, and participating at an advocacy level. The scientific community is finding its voice on this issue, and we want to support that.
What message would you like to share with the next generation of scientists about pursuing innovation without exploitation?
Science is about asking questions and challenging what we currently think is true. We’re at a point where, if you want to do biomedical research, there’s substantial evidence supporting a move away from animal models and no reason to shy away from that.
I also want to be realistic about the pressures students face. A lot of what determines which lab you go into is which lab has funding and is willing to take you. You don’t always have many options, and you may find yourself in an environment where someone tells you this is the gold standard or this is what we’ve always done. But students now have the evidence to push back on that, and that’s a meaningful shift from even five years ago.
The practical argument is also compelling. The FDA has stated that it expects animal use to become the exception rather than the rule within the next few years. NIH will no longer fund proposals that rely exclusively on animal models. If you want to be competitive, build a lab, and attract funding, your best bet is to develop expertise in NAMs now before the rest of the field catches up. The scientists who do that will be the ones defining what biomedical research looks like in twenty years.
What does a future without animal testing realistically look like, and how close are we to achieving it?
The dimension that doesn’t get enough attention is personalized medicine. Treatment tailored to your individual genetic and molecular profile is where medicine is headed, and animal models can’t capture that human variability. Moving away from animal models isn’t just an ethical choice. It’s a scientific necessity.
That’s what a future without animal testing looks like. A drug development pipeline where human biology is the model from day one. Instead of testing a compound in mice and hoping it translates, you’re screening it against human organ chips, running it through AI toxicity models, and building your safety case from human-relevant data before it ever enters a clinical trial.
The regulatory and funding infrastructure to support that transition is falling into place. The policy changes of the last three years have made sure of that.
NAVS History, A Voice for Those Who Cannot Speak
NAVS was founded in 1929 to raise awareness and advocate for the elimination of animal testing. Our mission has expanded to include encouraging replacements to classroom dissections, supporting sanctuaries for animals formerly used in research, and empowering scientists to pursue innovation.
If the truth about animal exploitation for science were widely known, it would end. That’s why we are focused on raising awareness about the cruel and outdated practice of using animals for research. Our vision is for ethical and effective, human-relevant solutions.
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