In a development that’s got dog lovers and scientists equally excited, a San Francisco-based biotech company called Loyal is working on something that sounds like it’s been pulled from the pages of a sci-fi novel: an anti-ageing pill for dogs. It’s not about vanity or immortality. It’s about helping our pets stay healthier, more active, and around a little longer. And in the process, it could teach us a lot about how we age, too.
The science behind a longer canine life
The drug at the centre of this effort is LOY-001, a long-acting injection that targets a hormone called insulin-like growth factor 1 (IGF-1). Larger dog breeds naturally produce more IGF-1, which is believed to be linked to why they often have shorter lifespans than smaller breeds. By lowering levels of this hormone, Loyal’s drug could potentially slow down ageing in big dogs—helping them live longer and enjoy those extra years in better health.
Loyal’s founder and CEO, Celine Halioua, has been vocal about the goal: not to create immortal dogs, but to extend their healthy years. “We love our dogs. We know they don’t live long enough. We want to change that,” she said in a recent interview with ABC News.
The treatment would be given every three to six months, and early tests suggest it’s well tolerated, with only mild side effects like occasional digestive upset. It’s currently being trialled in older dogs, and the results so far are promising enough for Loyal to move forward with FDA discussions.
But LOY-001 isn’t the only thing in the works. Loyal is also developing LOY-002—a daily pill designed for older dogs (10 years and up, and weighing at least 6.5 kg) to improve metabolic health. Rather than targeting just one hormone, it mimics the effects of caloric restriction, a method shown in multiple species to extend lifespan. Think of it as nudging the body into thinking it’s on a healthy diet, without actually cutting down their dinner portion.
Big step with the FDA
Back in November 2023, Loyal received what’s known as a “reasonable expectation of effectiveness” designation from the U.S. Food and Drug Administration. That might not sound particularly exciting, but it’s a big deal. It means the FDA sees enough evidence to believe the drug could do what Loyal says it can—extend the lifespan of senior dogs. It’s not the same as full approval, but it’s a necessary milestone on the way there.
As The Washington Post explained, it’s the first time the agency has ever considered approving a drug specifically aimed at extending lifespan. Loyal now has to provide further safety data, develop large-scale production capabilities, and complete more trials before hitting pharmacy shelves. The hope is that LOY-002 could be available by the end of 2025, with LOY-001 following in 2026.
The company’s founder has also been candid about the larger vision. Celine Halioua wrote in her blog post that their goal isn’t just business success—it’s reshaping the way we think about pet health. “Ageing is the single largest cause of suffering in dogs,” she wrote. “We believe it’s treatable.”
Could this mean longer lives for us too?
One of the reasons this research is so closely watched is because dogs aren’t just beloved pets—they’re also one of the best models for studying human ageing. They share our homes, our food habits, and even many of the same diseases that tend to show up with age. What we learn about how dogs age could help us understand ourselves better.
The Dog Aging Project, a separate initiative led by scientists at the University of Washington and Texas A&M, is also working on this angle. They’re studying how genetics, environment, and behaviour influence ageing in tens of thousands of dogs. One of their trials is testing rapamycin, a drug that has extended lifespan in mice and might offer similar benefits in dogs. If it works, it could eventually be studied in humans.
For companies like Loyal, success in dogs could lay the groundwork for longer-term ambitions in human medicine. If a drug can safely extend the healthspan of dogs—meaning the number of years lived without serious illness—it opens the door to exploring similar therapies for us. But Loyal is clear: their focus is on dogs, and human applications are still a long way off.
A growing field with real momentum
The anti-ageing industry is booming. Venture capital is pouring into research that looks at slowing the ageing process, and companies like Loyal are helping make the science more accessible and less abstract. Instead of lofty promises about eternal youth, they’re starting with a simple but powerful question: can we help our dogs live healthier lives for longer?
It’s a question many pet owners would answer with an emphatic yes. Obviously, the potential market for ageing treatments is enormous. There are around 90 million pet dogs in the U.S. alone, and many are considered part of the family. Extending their quality of life is something many owners would be willing to pay for—especially if it helps them avoid the heartache of watching a pet’s health decline rapidly with age.
As these drugs move through trials and closer to approval, there’s also a growing conversation about what it means ethically. Is it right to try to extend life artificially? Could it lead to new inequalities in pet care? Halioua has argued that this kind of innovation should be treated like any other medical advance—available, transparent, and subject to thoughtful oversight.
What comes next
Loyal is continuing trials and expanding its testing base, gathering more data on how dogs respond to the treatment across different breeds and health profiles. They’re also working on making their pricing model accessible. According to their website, they’re committed to making these treatments affordable enough to be widely adopted—not just a luxury for wealthy pet owners.
In the next year or two, we’ll likely hear a lot more about LOY-001 and LOY-002. If they pass regulatory hurdles, it could mark the beginning of a new era in veterinary care—one where treating the causes of ageing becomes as routine as vaccinating a puppy.
So no, we’re not talking about turning your Labrador into a forever puppy. But we might be on the brink of giving them more good years—and fewer ones spent dealing with arthritis, weakness, or metabolic disease. And for many dog owners, that’s more than enough reason to pay attention.
And who knows? In helping our dogs live longer, healthier lives, we might end up learning how to do the same for ourselves.