The future of science without animal testing

Moving toward a kinder approach

Since the passage of the Federal Food, Drug and Cosmetic Act in the U.S. in 1938, billions of mice, rats, guinea pigs, rabbits, dogs, fish, monkeys, chimpanzees and other animals have been used to study human diseases and test chemicals, drugs and vaccines. Safer, cheaper and more effective methods have existed for decades, and are gradually replacing animal testing, especially in the cosmetics industry. Still, an estimated 190 million animals worldwide languish in barren cages, suffering through invasive tests and enduring experiments that often end in death for necropsy. Outdated government laws and rules require companies to use them for safety testing. For research laboratories there are no such legal requirements, but the practice continues.

Now, U.S. labs are finally ending animal testing after decades of advocacy by Humane World for Animals and others. Three of the federal agencies that provide funding and establish testing requirements are decisively moving away from animal methods. In 2025 and 2026, the National Institutes of Health, the world’s largest funder of biomedical research; the Food and Drug Administration; and the Environmental Protection Agency all announced they would encourage the development and use of human-based technologies, including lab-grown cells and organoid models, as well as computational models that use human data.

“It’s come to this really critical point,” says Kathleen Conlee, vice president of animal research issues for Humane World. “The animal tests aren’t giving us the information we need. We have to do something different. This is the moment we need to seize.”

Siqui Sanchez/Getty Images

Rabbits are among the animals most commonly used in research and testing. Even with the end of the Draize test, in which chemicals were dropped into the eyes of restrained rabbits, an estimated 111,000 remain in U.S. labs alone.

A different kind of laboratory

Instead of another animal lab, NIH is establishing an organoid center at the Frederick National Laboratory for Cancer Research in Maryland, where scientists will develop small models of the liver, lung, heart and intestines grown from human cells. The aim is to create reproducible, scientifically reliable non-animal models that can be used around the world.

Humane World Action Fund is working to ensure that NIH, FDA and EPA carry out commitments to non-animal testing before the end of the Trump administration, says Tracie Letterman, vice president of federal affairs. The Humane World team is asking that the federal agencies direct their funding toward the development of non-animal approaches and make it clear that those can be used for safety testing.

Until now, almost half of the NIH budget—$20 to $25 billion—has been spent on research and testing that uses animals but only a small fraction has been used to support non-animal methods. “It’s critical that we maintain this pressure,” says Letterman.

Pakhnyushchyy/Getty Images

When Amanda Ulrey, president of the Institute for In Vitro Sciences, first arrived at the nonprofit in Gaithersburg, Maryland, 20 years ago, non-animal methods for toxicity testing developed there had already been proven effective. Today, those tests have been accepted by the federal government and adopted by private companies.

With the NIH, FDA and EPA announcements, Ulrey hopes for quicker progress. Scientists understand so much, she says—they can identify the events that lead to itchy skin at the molecular level. “There’s a lot of potential to make big moves now.”

Inside In Vitro Sciences’ labs, researchers are using new ways to test safety without animals. White-coated technicians work with precisely calibrated pipettes for handling human cells and cytometers that rapidly count them. Incubators provide just the right temperature, CO₂ level and humidity for tissue shipped in weekly from Boston and abroad. Lab-grown human skin cells are exposed to a test material and UV light, then scanned. If the cells are still alive, they metabolize a dye that turns purple. There are human lung slices the size of a toothpick’s point, ready to be inserted into a machine that surrounds them with smoke.

What’s missing: rows of animals. Not a single rabbit restrained so a corrosive substance can be dropped into their eyes or applied to their shaved skin. Not a single rat with a cup over their nose, forced to breathe in a toxic substance. Not a single cage.

This is a vision of the future, across the United States and around the world: better safety tests, revolutionary research. All without animal suffering.

The survivors

With the help of Humane World for Animals, chimpanzee research has ended in the U.S., but tests and experiments on primates continue, with 70,000 macaques still used in labs and tens of thousands more used for breeding. The same is true for rabbits and beagles, thousands of whom are still bred and used for testing and research. Below are the stories of four animals who survived.

Brandon Wade/AP Images for Humane World for Animals

Big Bit, 38 years old

Black Beauty Ranch sanctuary, Texas

The oldest rhesus macaque at our Black Beauty Ranch sanctuary, Big Bit started her life as “RH-1266,” a subject in a long-shuttered lab doing HIV and hepatitis research on primates. She was listed as “on study” and likely lived in a row of sterile metal cages. Big Bit was trained to present her limbs for blood draws and injections, and to climb into a box for transport to experiments.

In 1997, after seven years in the lab without ever going outside, she arrived at the sanctuary, where she now roams a large, wooded yard open to the sky. As with other macaques, she is “reactive”—she may perceive eye contact or close proximity as a threat and respond by posturing, opening her mouth or giving a raspy bark, says Christi Gilbreth, the sanctuary’s senior specialist of outreach and development.

Big Bit, who has arthritis, spends much of the day napping and lounging. But she’s quick to vocally join disputes of her macaque neighbors. In the lab, she might once have spent hours in fear, hearing or smelling lab attendants and waiting for their approach—anticipating the needles, pain and restraints that followed. Now she has no need to worry. The humans bring only food.

Marci Smeltz

Donny, 8 years old

Adopter’s home near Research Triangle Park, N.C.

Donny, a New Zealand white rabbit, was the first of two animals adopted from the EPA lab in Research Triangle Park in June 2025. His adoption marked the agency’s renewed commitment to phasing out the use of mammals for chemical safety testing.

EPA scientist Marci Smeltz, who with her husband already had a rabbit, dogs and lizards, says she happily agreed to take Donny. At the end of one workday, Smeltz—who develops non-animal methods for testing the effects of inhaling chemicals—carried the big rabbit out of the EPA lab and into the sunshine for the first time.

She then drove him slowly home, radio off, so he could adjust.

When she is home, Donny roams the kitchen and living and dining rooms. (He never had much room to hop around in the lab.) Now he does binkies—joyous leaps and twists—and zooms around in the high-energy movement known as the “bunny 500.” If Smeltz and her husband are away, he’s in a pen with a dog bed, a king-size comforter, a crate and a litter box. “He’s a big splooter,” Smeltz says. “He’ll lay his back legs out and relax. He’ll do this big yawn. He’s super chill.” He likes bell peppers and being petted, and he gets along with Smeltz’s 14-year-old poodle mix. Donny doesn’t like to be held, but he’s curious and loves people. When Smeltz comes home from work, he’s excited to see her (she gives him a treat). When she comes downstairs in the morning, he greets her—happy for another day in a real home.

Chimp Haven

Hope, 29 years old

Chimp Haven sanctuary, Louisiana

Hope was born into a world in which she had no choices. The lab in New Mexico, then called the Coulston Foundation, exposed chimpanzees to infectious diseases such as hepatitis and HIV. Repeated violations of the federal Animal Welfare Act led to the deaths of 48 animals there in less than a decade.

In 2002, when Hope was five, the invasive experiments and poor conditions ended as research was halted. But she did not leave what became the Alamogordo Primate Facility for another 16 years, after persistent appeals by Humane World for Animals and other advocates finally made her release possible. Hope went to Chimp Haven, a sanctuary established by the NIH for federally owned chimpanzees.

Now she can choose.

When it’s time to clean her yard, trainers offer a flying disc or a tennis ball: If she chooses the flying disc, they’ll return later. If she chooses the tennis ball, she moves to her indoor “bedroom” for a treat while they clean the yard.

Hope doesn’t like to be locked inside, even for an hour, but she accepts it if she can choose when it happens, says Michelle Reininger, Chimp Haven colony director. Most of the time, when she’s free to move about, Hope is affectionate, often hugging other chimpanzees in her group. “She is one of the sweetest chimps I know. Very loving, very caring,” says Reininger.  “She is the glue that holds them together.”

Anita Archambeau

Phoebe, 4 years old

Adopter’s home near Harrisburg, PA

Phoebe was among the last of more than 4,000 beagles rescued from the Envigo breeding site in Cumberland, Virginia, during the summer of 2022. The rescue was carried out by Humane World for Animals and our partners after the company agreed to shut down the facility following a U.S. Department of Justice investigation of Animal Welfare Act violations. At 13 pounds, she was emaciated—dogs there were fed too little poor-quality food. Of her litter of seven, only one other made it out alive.

When Anita Archambeau took her home to central Pennsylvania, she had to teach Phoebe how to use a bowl. After some weeks, Phoebe howled for the first time. Imitating Archambeau’s two other beagles, she did zoomies. She learned how to get a belly rub and how to stop when running on grass. She overcame her fear of men and felt comfortable around Archambeau’s husband.

“She started to develop her queen complex,” Archambeau says. “She dominated the house.”

Then, Archambeau saw a post from our Pennsylvania state director Kristen Tullo looking for Envigo beagles to visit the state capital. Phoebe became a lobbyist for a bill to protect dogs and other animals in Pennsylvania laboratories. The proposed legislation unanimously passed the Senate last year, and Phoebe was awarded the Pennsylvania Freedom Medal.

Still, she has her moments, says Archambeau. Unexpected noises, like a cell phone beep, make her shake. But medications help manage her anxiety. She’s loving and cuddly and makes Archambeau and her husband laugh, running across the top of the couch, carrying stuffed animals. “She’s an amazing little soul.”