Drug To Help Dogs Live Longer Has ‘Reasonable Expectation of Effectiveness,’ FDA Says

The San Francisco-based biotech startup that developed the drug celebrated the determination as a "milestone," though there's scant evidence so far that it can reliably lengthen dogs' lifespans.
Experimental Dog Longevity Drug Has ‘Reasonable Expectation of Effectiveness,’ FDA Says

The FDA has said that an experimental drug that purports to increase the “the healthy lifespan” of larger dogs has a “reasonable expectation of effectiveness,” a milestone that could clear the way for the veterinary drug to be available to the public within the next few years. 

Loyal, the San Francisco-based biotech startup that developed the drug, announced on Tuesday that the FDA had made the determination after reviewing the company’s data and results, a critical hurdle in the company’s path to receiving conditional temporary approval to market the drug, LOY-001.


“Today’s announcement shows the FDA believes Loyal’s approach is valid,” the company said in a release.

If the FDA also approves the company’s manufacturing and safety data packages, Loyal will be able to market the longevity drug to owners of large dogs as soon as 2026. The startup will then have five years to collect further data needed to apply for full approval. 

The company, which has received a total of $58 million in funding, has been researching ways to increase the lifespan of dogs since it was founded in 2020. In a statement, Loyal CEO Celine Halioua celebrated Tuesday’s “milestone” as a product of “years of careful work,” but said her team will “continue to work just as diligently to bring this and our other longevity programs through to FDA approval.”

Loyal’s drug focuses on reducing the amount of a growth hormone called insulin growth factor-1, or IGF-1. that is found in high levels in many large dogs, which some have suspected is the reason they tend to have shorter lifespans than smaller breeds. 

Despite the FDA's ruling, there's scant evidence that Loyal’s drug can reliably lengthen the lifespan of dogs. The New York Times noted that there is just one small study indicating that LOY-001 might mitigate some aging-linked metabolic changes, but Loyal has not proven that it actually extends the lives of dogs.


Even if the drug does work, it's not clear that it will provide dramatic lifespan improvements. Loyal CEO Celine Halioua told the Times that the company aspires to claim a one-year lifespan extension from the drug. 

In recent years, the FDA has been empowered by Congress to conditionally approve certain “innovative treatments” for animals that require complex clinical trials, allowing for their accelerated use on “animals and species that have few drugs approved for them

By zeroing in on canine longevity, Loyal finds itself at the intersection of two areas of recent American fascination. Americans spent $102 billion on pets in 2021, almost 80 percent more than the $57 billion it budgeted for pets in 2012. Simultaneously, interest in advancing human longevity has become a subject of fascination for both investors and consumers.

Halioua has suggested that her company’s tests on dogs could one day lead to breakthroughs for humans too. 

“Dogs are unquestionably considered the best model of human aging,” she told Bloomberg in 2021. “They also develop age-related diseases over time. If we can do this for dogs, people will want it, too.”