The first anti-aging pill for dogs is entering trials — and an 11-year-old whippet named Boo is the first to try it

• A once-daily, meat-flavored longevity tablet is being trialed in old dogs.
• The drug aims to extend dogs' lifespans, keeping old dogs healthier and alive for longer.

A first-of-its-kind anti-aging tablet for dogs is now being tried out in elderly pets across the country — and so far, these old dogs love their new drugs.

On average, our dogs die after about a decade or so with us, but these new chewables are designed to extend the lives of dogs of almost every size for just a little while longer. If they work, they'll make aging dogs feel and act healthier, younger, and more vibrant. And it'll all be done with a once-daily meaty-flavored chewable drug.

Boo, an 11-year-old whippet dog from Pennsylvania, is the very first participant in this clinical trial, from the veterinary medicine startup Loyal. This is the latest venture from the company, which is waiting on FDA approval for another canine anti-aging product: an injectable drug for large-breed dogs over 40 pounds and 7 years old.

The new STAY study is one of the largest, most diverse dog aging studies of its kind — with plans to enroll more than 1,000 aging dogs across 50 different US sites. The goal is to determine whether Loyal's newly-developed medication, called LOY-002, will actually work to extend dog lifespans. The company is hoping to boost dogs' lifetimes by at least an extra year.

"A clinical trial doesn't mean the drug works — it means we're going to test whether it works," aging expert Daniel Promislow, who directs the Dog Aging Project, another large study of aging dogs, told Business Insider. (Promislow is not involved with Loyal's drug development.)

One month into this multi-year trial, there's no way to know yet whether the drug works or not, but we do know that Boo is already loving his new daily anti-aging routine. He gets to eat flavored tablets every day, which are infused with a beef-like, savory taste. At mealtimes, Boo's eyes stare up longingly at the counter. No spoonful of sugar is needed to help his medicine go down.

"Boo's owner can just open her hand," Loyal's director of clinical development, veterinarian Ellen Ratcliff, told BI. "It becomes kind of like a treat."

Dog owners may get access to this drug as early as 2025

Loyal wouldn't share the exact formula or active ingredients in LOY-002, but Ratcliff says it's basically working to boost a canine metabolism, "that becomes dysfunctional as dogs age."

LOY-002 was designed to be used in almost all elderly dogs, aged 10+ and weighing over 14 pounds. While the study will take at least four years to produce results, the company is hoping that the pill might win a conditional approval with the FDA in early 2025, before clinical results showing whether the drug actually works are available.

It's unclear exactly how much the product would cost, but the company says it is committed to making this an "affordable" treatment, somewhere in the "mid double-digits" per month for pet owners.

"It's going to be cash-pay accessible," Loyal CEO and founder Celine Halioua previously told BI. "It's being designed for the majority of Americans to be able to afford it, and it's not going to need insurance or anything like that."

Promislow, now in the midst of raising more cash to fund his own dog aging studies, says with 1,000 dogs slated to be in Loyal's trial, it should produce some very clear data, capable of detecting even a modest life extension effect.

"I certainly hope that Loyal is successful at increasing healthy lifespan in dogs," he said. "If this is a really safe intervention — with no side effects — that adds even a few months of healthy lifespan to the average dog, that could be meaningful for some people and their dogs."