LOY-002 for Dogs

Loyal's senior-dog lifespan pill: where FDA review stands, when it might launch, and what the STAY study is testing.

By La Petite Labs Editorial 7 min read

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Woman hugging a golden retriever while holding a Hollywood Elixir box
Contents

LOY-002 is not available yet, and Loyal hasn't published a price. It's a daily pill being developed by the veterinary biotech company Loyal to extend healthy lifespan in dogs aged 10 and older, weighing at least 14 lb. The FDA has accepted two of the three main sections of its application: the preliminary effectiveness section (RXE) and the target animal safety section. No release date is confirmed. Loyal expects the FDA to review the last section, manufacturing, in 2027, and a launch would then depend on conditional approval.

Here's where things stand, what the drug is designed to do, and what the 1,300-dog STAY study is testing.

La Petite Labs publishes this guide and makes Hollywood Elixir, a dog supplement. We're not affiliated with Loyal.

Is LOY-002 available? Where can I buy it?

No, you can't buy LOY-002 yet, from Loyal, a vet or any online store. It isn't approved, and the STAY study is fully enrolled, so there's no way to get it through the trial either.113 There are no authorized sellers, so avoid any website claiming to offer it.

When it does launch, it will be a prescription drug, available through veterinarians.

LOY-002 for Dogs at a glance

What it is
A daily prescription pill for senior dogs, in development
Who it's for
Dogs 10 years and older, 14–179 lb
How it works
Aims to improve insulin sensitivity and lower insulin levels
FDA progress
Effectiveness (RXE) accepted Feb 2025 · Safety (TAS) accepted Dec 2025 · Manufacturing in progress
Release date
Not confirmed; Loyal expects the manufacturing review in 2027
Price
Not published; one media report says around $100 a month, unconfirmed
Big study
STAY: about 1,300 dogs at 70+ US clinics, fully enrolled since July 2025, up to four years

Loyal’s three dog longevity drugs, compared

LOY-002LOY-001LOY-003
ForSenior dogs, 10+ years, 14 lb+Large dogs, 7+ years, 40 lb+Large dogs, 5+ years, 60 lb+
FormatDaily pillInjection, a few times a yearDaily pill
TargetInsulin and metabolismIGF-1 (a growth signal)Growth biology
FDA progressRXE + safety accepted; manufacturing in progressRXE accepted (2023)RXE accepted (2026)

Competitor label and pricing facts checked November 6, 2026. Sources are listed in the References section below.

Woman holding a Hollywood Elixir box beside a pug, a terrier and a food bowl

How much will LOY-002 cost?

Loyal hasn't published a price. Entrepreneur has reported an expected price of around $100 a month,11 but Loyal's own announcements haven't confirmed a figure. The company says it will share more as it gets closer to conditional approval.1

When budgeting, remember that the cost will include more than the pill. As a prescription medicine, it would mean an initial vet visit and whatever check-ups your vet recommends.

Woman in sportswear holding a Hollywood Elixir box beside a black-and-tan dog outdoors

When will LOY-002 be released?

There's no confirmed release date. Two of the three main sections of LOY-002's FDA application are accepted. In February 2026, Loyal said it planned to submit the third, manufacturing, later that year,10 and it expects the FDA's review in 2027.3

A launch would follow only if the FDA then grants conditional approval, and Loyal itself notes that approval isn't guaranteed.1 On that timeline, 2027 is the earliest realistic year, not a promise.

Woman holding a Hollywood Elixir box above her forehead beside a Bernese mountain dog outdoors

What is LOY-002?

LOY-002 is a once-daily pill that Loyal is developing to help senior dogs live longer, healthier lives. Loyal is a San Francisco veterinary biotech company, founded in 2019 by Celine Halioua, that works only on drugs for healthy lifespan in dogs. LOY-002 is the furthest along of its three programs.

Loyal hasn't disclosed the active ingredient. Publicly, it describes the goal as improving insulin sensitivity and lowering insulin in older dogs.1

Golden retriever nuzzling a woman holding a Hollywood Elixir box on the grass beside a food bowl

Which dogs is LOY-002 for?

Loyal is developing LOY-002 for dogs 10 years and older and weighing 14 to 179 lb.1 That covers most senior dogs, from a Beagle to a Great Dane. Very small dogs under 14 lb fall outside the range. The final label will set the exact criteria, and your vet will still decide whether it suits your dog's health and medications. If yours falls outside the range, here's what to do.

LOY-002 isn't available yet, and Loyal hasn't published a price.

How does LOY-002 work?

LOY-002 targets insulin, the hormone that helps the body move sugar from the blood into cells for fuel. As dogs age, their tissues can become less responsive to insulin, so the body produces more of it to do the same job.

Loyal's idea is that improving insulin sensitivity, and bringing insulin levels down, could slow some of the metabolic changes that come with age and keep dogs healthier for longer.4 It's a metabolic approach to aging, not a diabetes treatment.

Overhead view of a black-and-white dog beside a food bowl and Hollywood Elixir box

Why insulin? The 451-dog study

In a 2025 study of 451 adult companion dogs, dogs with higher insulin levels tended to be frailer and to score lower on quality of life.5 That's a link, not proof of cause, and the dogs didn't receive LOY-002. All of the authors worked, or had worked, for Loyal. Still, it's the clearest public explanation of why Loyal chose this target.

Woman smiling beside a golden retriever, a green food bowl and a Hollywood Elixir box

The STAY study: what it's testing

STAY is designed to test whether LOY-002 extends lifespan and improves health. About 1,300 senior dogs at more than 70 veterinary clinics across the US are receiving either LOY-002 or a placebo every day, and neither owners nor vets know which.213 Enrollment finished in July 2025. Dogs are followed for up to four years, tracking lifespan, health and quality of life through vet exams and owner reports.

The placebo comparison is what makes STAY worth waiting for. Senior dogs have good weeks and bad weeks for all sorts of reasons, and a randomized, blinded comparison is how researchers separate a drug's effect from everything else.

Man holding a Hollywood Elixir box while sitting on an outdoor sofa with a golden retriever

How many years could LOY-002 add?

Nobody knows yet. That's the question STAY is built to answer. According to Fortune, the study was designed to detect a difference of at least a year in lifespan between treated and placebo dogs.6 That's a detection target, not a result. Until results are in, any specific number is speculation.

How the FDA review works

LOY-002 is going through the FDA Center for Veterinary Medicine's expanded conditional approval pathway. Three main technical sections have to be accepted first.17

  1. Reasonable expectation of effectiveness (RXE): evidence the drug is likely to work as intended. This is a lower bar than the "substantial evidence" needed for full approval.
  2. Target animal safety (TAS): evidence the drug is safe in the animal it's meant for, dogs.
  3. Manufacturing (CMC): proof the drug can be made consistently and to standard.

With all three accepted, Loyal can apply for conditional approval. STAY's results could then support an application for full approval.

STAY follows about 1,300 senior dogs for up to four years. It's designed to test whether LOY-002 extends lifespan.

Spotted gray dog beside a Hollywood Elixir box held in a person's hand

LOY-002 milestones so far

  • February 2025: the FDA accepts LOY-002's reasonable expectation of effectiveness (RXE).
  • April 2025: the STAY study passes 1,000 enrolled dogs.12
  • July 2025: STAY completes enrollment at about 1,300 dogs.13
  • December 2025: the FDA accepts the target animal safety section, announced January 2026.8
  • February 2026: Loyal raises $100 million to prepare for launch and says the manufacturing section will be submitted later in the year.10
  • 2027 (expected): FDA review of the manufacturing section.3
Golden retriever nuzzling a man holding a Hollywood Elixir box beside a food bowl

What conditional approval would mean for your dog

If LOY-002 is conditionally approved, your vet could prescribe it while STAY is still running. Its label would say it is "conditionally approved by FDA pending a full demonstration of effectiveness."7

Conditional approval lasts one year and can be renewed each year, for up to five years in total. In that time, the company has to show the stronger evidence needed for full approval.7 So a dog starting LOY-002 under conditional approval would be on a drug whose safety and manufacturing the FDA has reviewed in full, while its effectiveness is still being confirmed.

Vets also can't use a conditionally approved drug off-label, so only dogs that fit the label could get it.7

Golden spaniel eating from a green bowl beside a Hollywood Elixir box

Is LOY-002 safe?

The FDA has accepted LOY-002's target animal safety section, a major step. Loyal says the package included testing at the intended dose and at higher multiples, plus field data from more than 400 dogs, some treated for up to a year.8 The full side-effect and interaction details haven't been published. They'll appear on the final label, and your vet will weigh them against your dog's health.

LOY-002 vs LOY-001 vs LOY-003

More on LOY-001 · More on LOY-003 · Rapamycin for dogs · All dog longevity drugs

If your dog is already in STAY

Keep following the study team's instructions, and talk to them before adding any new supplement, food or medication. Even everyday nutrition products can matter in a trial. Don't change your dog's routine to try to work out whether they're on the drug or the placebo.

Woman holding a Hollywood Elixir box beside a dapple dachshund and green food bowl on a sofa

What you can do for a senior dog now

You don't have to wait for a drug to support healthy aging. The things with the strongest evidence are already available:

  • Keep your dog lean. In a lifelong study of 48 Labradors, dogs fed 25% less than their littermates from puppyhood lived a median of 1.8 years longer.9 The lesson is to hold a healthy weight. Don't cut a senior dog's food on your own; ask your vet for a target weight.
  • Book twice-yearly senior check-ups. They catch problems early.
  • Keep them moving, and keep their minds busy with walks, sniffing and puzzle feeders.
  • Feed a complete diet, and track appetite, weight and energy.

Our dog age calculator and senior dog guide can help you plan.

Woman cuddling a brown-and-white spaniel while holding a Hollywood Elixir box

What to ask your vet about LOY-002

  • Would my dog be a likely candidate when it launches, given their age, weight and health?
  • Which baselines are worth recording now, such as weight, body condition and routine bloodwork?
  • Do any of my dog's current medications raise questions for a metabolism-targeting drug?
  • What can we do today for healthy aging while we wait?

Where daily nutrition fits

We make Hollywood Elixir, a daily nutrition powder for adult and senior dogs. It's built around nicotinamide riboside, an NAD+ precursor, with CoQ10, glutathione and 14 more actives, and every active amount is printed on the label. It's a supplement, not a drug: it isn't designed to do what LOY-002 is being tested for, and it hasn't been tested for lifespan. Its case is practical: one scoop in the food bowl instead of a cupboard of separate supplements. If that suits your senior dog, discuss it with your vet. See the full formula and serving guide, or read our NAD+ for dogs guide for the science.

The strongest healthy-aging tools are available today: a lean body, regular check-ups, movement and good food.

Educational content only. This material is not a substitute for veterinary advice. Always consult your veterinarian about your dog’s specific needs. These statements have not been evaluated by the Food and Drug Administration. Products mentioned are not intended to diagnose, treat, cure, or prevent any disease.

Glossary

Insulin sensitivity: how readily the body's tissues respond to insulin.

RXE: reasonable expectation of effectiveness, the FDA's preliminary effectiveness standard.

TAS: target animal safety, the safety section of a veterinary drug application.

CMC: chemistry, manufacturing and controls, the manufacturing section.

Conditional approval: FDA permission to sell a drug for up to five years while full effectiveness evidence is collected.

Placebo: a look-alike pill with no active drug, used for comparison.

Related Reading

Aging & Senior Dog Guidance
• Dog Age Calculator
• Dog Lifespan by Breed
• Dog Dementia
• Lethargy in Dogs
• My Dog Won't Eat
• Dog Pacing At Night
• Dog Licking Paws
• Can Dogs Dehydrate

Healthy Aging Support
• NAD+ for Dogs
• NMN for Dogs
• Antioxidants Supplements for Dogs
• Best Senior Dog Supplements & Vitamins
• Dog Longevity Drugs
• Rapamycin for Dogs

References

Sources and further detail

  1. Loyal, *For veterinarians* (program status, eligibility, pathway; checked November 2026)
  2. Loyal, *Clinical trials* (STAY design and enrollment)
  3. dvm360 (13 Jan 2026), Lifespan extension drug in development for senior dogs reaches a new milestone
  4. Loyal, *Metabolic dysfunction and aging*
  5. McKenzie B, Peloquin M, Graves JL et al. *Scientific Reports* (2025). Changes in insulin, adiponectin and lipid concentrations with age are associated with frailty and reduced quality of life in dogs
  6. Fortune, 11 April 2026: report on Loyal, the STAY study and the FDA pathway
  7. FDA, *Conditional approval explained: a resource for veterinarians*
  8. Loyal (Jan 2026), LOY-002 target animal safety announcement
  9. Kealy RD, Lawler DF, Ballam JM et al. *JAVMA* (2002). Effects of diet restriction on life span and age-related changes in dogs
  10. Loyal (11 Feb 2026), Loyal raises $100M Series C, led by age1, to advance the first canine longevity drug
  11. Entrepreneur, This $100-a-month pill can extend the life of your dog
  12. dvm360 (Apr 2025), Clinical trial for longevity drug meets goal of enrolling 1,000 dogs
  13. Loyal (14 July 2025), The STAY study finishes enrollment: a big day for dog-kind

FAQ

Is LOY-002 approved by the FDA?

As of October 6, 2026, Loyal’s reviewed sources still describe LOY-002 as in development. The company reports acceptance of its preliminary-effectiveness and target-animal safety submissions. Those steps are not the final conditional-approval decision.

Is LOY-002 a pill or an injection?

LOY-002 is being developed as a daily pill for senior dogs. LOY-001 is the separate long-acting injection programme for large dogs.

What dogs is LOY-002 intended for?

Loyal currently names dogs aged ten or older and weighing at least 14 lb. These are intended development criteria, not a final approved label or a guarantee of individual suitability.

Can my dog join the STAY trial?

The current Loyal clinical-trials page says STAY is fully enrolled. An older recruitment page or meeting the age and weight criteria does not establish that a place is available.

How many dogs are in STAY?

Loyal reports approximately 1,300 dogs across 70 US veterinary practices. STAY compares the study drug with placebo and follows lifespan, health and quality of life. Enrollment completion does not mean the study is finished.

How does LOY-002 aim to work?

It aims to improve insulin sensitivity and lower circulating insulin as a way to address age-related metabolic dysfunction. That is the programme’s intended mechanism and longevity hypothesis, not proof that a particular dog will benefit.

How much longer do dogs live with LOY-002?

A reliable added-lifespan figure is not established in the sources reviewed here. STAY is designed to test lifespan and health outcomes. A programme goal, news prediction or owner anecdote should not be presented as a completed trial result.

What is known about side effects?

Loyal reports an accepted safety submission including target-dose-multiple testing and field information from more than 400 dogs. Its public report is not a complete final prescribing label or a guarantee of safety for every dog and medication combination.

Can I buy LOY-002, and what is the price?

We could not verify a confirmed commercial launch, final retail price or approved prescribing label in the current sources. Follow dated Loyal announcements and consult your veterinarian if an authorized product becomes available.

Can a dog in STAY take Hollywood Elixir?

Ask the study team before adding or changing any supplement. Hollywood Elixir is a 17-active healthy-aging nutrition powder, not a substitute for LOY-002, and the evidence here does not establish safe co-administration with the investigational drug.

Dalmatian looking toward a Hollywood Elixir box held in a person's hand

Discover LPL-01: How This Fits Into a Larger Canine Longevity System

Aging in dogs is not driven by a single pathway. It’s the result of interacting biological systems—energy metabolism, oxidative stress, immune signaling, and structural integrity—changing over time.

This article explores one piece of that puzzle. If you want to understand how these pieces connect—and what actually moves the needle—you need to zoom out.

Start with the underlying science: