Loyal for Dogs: The Company Behind LOY-002

Who Loyal is, what its three dog drugs do, where FDA review stands, and whether the company is legit.

By La Petite Labs Editorial 9 min read

As Seen On

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

Loyal is a real, venture-funded San Francisco company, but none of its dog longevity drugs is approved yet. It was founded in late 2019 by Celine Halioua and has raised over $250 million. Its lead drug, LOY-002, a daily pill for senior dogs, has cleared two of three main FDA sections. No price or release date is confirmed.

Here's who runs Loyal, what its three drugs are, what critics say, and when your dog might be able to get one.

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

What is Loyal for dogs?

Loyal is a veterinary drug company developing what it calls the first drugs meant to help dogs live longer, healthier lives. It's based in San Francisco, and all three of its programs are for dogs.32 "Loyal for dogs" isn't a product you can buy. It's the company's name, and its drug candidates are called LOY-001, LOY-002 and LOY-003.

All three are still in development. Each would be a prescription drug, given or prescribed by a veterinarian.1

Loyal at a glance

What Loyal is
A San Francisco veterinary drug company developing lifespan drugs for dogs
Founded
Late 2019, by founder and CEO Celine Halioua
Funding
Over $250 million, including a $100 million Series C in February 2026
Drugs in development
LOY-002 for senior dogs; LOY-001 and LOY-003 for large dogs
Approved drugs
None yet; LOY-002 is closest, with two of three FDA sections accepted
Earliest launch
Not confirmed; Loyal expects the FDA to review LOY-002's manufacturing section in 2027
Price
Not published; press reports range from $50 to about $100 a month
Cats
No cat program

Loyal's three dog drugs compared

LOY-002LOY-001LOY-003
ForDogs 10+ years, 14 lb+Dogs 7+ years, 40 lb+Dogs 5+ years, 60 lb+ (some Loyal pages say 7+ and 40 lb+)
FormatDaily flavored tabletVet-given injection every 3 to 6 monthsDaily tablet
TargetInsulin and metabolismIGF-1Growth hormone and IGF-1
FDA progressEffectiveness and safety accepted; manufacturing in progressEffectiveness accepted, November 2023Effectiveness accepted, September 2026
Pivotal studySTAY: about 1,300 dogs, fully enrolledNone listed yetNone listed yet
Can you get it?NoNoNo

Competitor label and pricing facts checked November 11, 2026. Sources are listed in the References section below.

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

Is Loyal legit?

Yes, Loyal is a legitimate company, but its drugs are still unproven. It has FDA milestones on record, a 1,300-dog placebo-controlled study under way, and research published in peer-reviewed journals.13 What it doesn't have yet is an approved drug or a finished lifespan result.

It helps to separate the company from the sellers. Loyal is working through the FDA's Center for Veterinary Medicine. Any website selling "LOY-002" or "Loyal pills" today isn't selling Loyal's drug, because nothing has been approved for sale.1

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

Who owns the Loyal dog company?

Loyal was founded in late 2019 by Celine Halioua, who is still its CEO.45 Its legal name is Loyal Animal Health, Inc.1 It's backed by venture investors including age1, Baillie Gifford, Bain Capital Ventures, Khosla and Valor, and Laura Deming of The Longevity Fund sits on its board.4

Loyal is funded by private investors. We found no stock-exchange listing or IPO as of November 2026, so there are no Loyal shares to buy on a public market, whatever "Loyal stock" searches suggest.

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

How much money has Loyal raised?

Loyal has raised more than $250 million since it was founded, according to its February 2026 announcement.5 That total includes a $100 million Series C on 11 February 2026, led by age1 with Baillie Gifford and existing investors. Loyal said the money would carry LOY-002 through its remaining FDA requirements and prepare for launch.5

The total has grown quickly. In February 2025, after a $22 million round, Loyal put its total at over $150 million.6

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

What drugs is Loyal developing?

Loyal is developing three drugs: one for senior dogs of most sizes, and two for large dogs, which tend to live shorter lives.12 None is approved, and none can be bought.

Loyal is a real company with real FDA milestones. What it doesn't have yet is an approved drug.

What is LOY-002?

LOY-002 is Loyal's lead drug: a daily flavored tablet for dogs 10 and older weighing at least 14 lb.6 Loyal says it aims to extend healthy lifespan by lowering insulin and improving insulin sensitivity.1 Loyal hasn't named the active ingredient, and it says its drugs and their exact mechanisms will stay confidential until closer to launch.1

Its main test is the STAY study: about 1,300 senior dogs at 70 US veterinary practices, given LOY-002 or a placebo for up to four years.3 Our LOY-002 guide covers price, timing and the study in depth.

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

What are LOY-001 and LOY-003?

LOY-001 and LOY-003 are Loyal's two drugs for large dogs. Both target IGF-1, a growth hormone signal that Loyal believes is linked to big dogs' shorter lives.1 LOY-001 is a long-acting injection that a vet would give every three to six months, for dogs 7 and older weighing at least 40 lb.72

LOY-003 is a once-daily tablet that lowers growth hormone and IGF-1.8 Loyal's products page lists it for dogs 5 and older weighing at least 60 lb, though some of its vet materials say 7 years and 40 lb.21 Our LOY-001 and LOY-003 guides explain each one.

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

Has Loyal for dogs received FDA approval?

No. As of November 2026, the FDA hasn't approved any Loyal drug, conditionally or fully.1 What Loyal has are accepted sections of its applications for conditional approval:

  • November 2023: the FDA accepted LOY-001's reasonable expectation of effectiveness (RXE). Loyal called it the first such acceptance for lifespan extension.7
  • February 2025: LOY-002's RXE was accepted.6
  • December 2025: LOY-002's target animal safety section was accepted, announced in January 2026.169
  • September 2026: LOY-003's RXE was accepted, Loyal's third.8

LOY-002 still needs its manufacturing section accepted before conditional approval can be considered.9 Loyal itself notes that approval isn't guaranteed.1

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

What research has Loyal published?

Loyal's team lists 11 papers on dog aging from 2021 to October 2026, in journals including GeroScience, Scientific Reports and the Journal of Veterinary Internal Medicine.1 Most describe how dogs age and how to measure it. The newest, in October 2026, looks at lessons from dog lifespan drugs for human medicine.

The paper closest to LOY-002 is a 2025 study of 451 adult dogs. Dogs with higher insulin tended to be frailer and to score lower on quality of life, and all of the authors were current or former employees of the company.11 That's a link, not proof that lowering insulin helps. Loyal hasn't published LOY-002's effectiveness data; it says it will share more as launch gets closer.1

What do skeptics say about Loyal?

The main criticism of Loyal is that it hasn't yet shown its drugs make dogs live longer. When LOY-001 reached its 2023 FDA milestone, Vice reported there was scant evidence it could reliably lengthen dogs' lives, noting that the New York Times had pointed to a single small study.12 The FDA's bar for conditional approval is a reasonable expectation of effectiveness, short of the full standard.10

Others question the idea itself. In Slate in 2025, a veterinary oncologist said she would stay skeptical until she could see the drug's full composition and data, and bioethicist Jessica Pierce argued that lifespan drugs serve owners more than dogs.13 Loyal's timelines have also slipped: in February 2025 it expected to finish LOY-002's safety and manufacturing requirements by the end of 2025, and the manufacturing review is now expected in 2027.69

As of November 2026, no vet, pharmacy or website can sell you a Loyal drug.

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

When will Loyal be available for dogs?

There's no confirmed date. In February 2026, Loyal said it planned to submit LOY-002's last major section, manufacturing, later that year, and it expects the FDA to review it in 2027.59 Only after that could Loyal seek conditional approval. On that timeline, 2027 is the earliest realistic year for LOY-002, and that's our reading, not a promise.

LOY-001 and LOY-003 are further back, with only their effectiveness sections accepted.18 Loyal hasn't given a launch year for either.

Golden retriever nuzzling a man holding a Hollywood Elixir box beside a food bowl

How much will the Loyal dog drug cost?

Loyal hasn't published a price for any of its drugs. Its pages for owners and vets give no figures as of November 2026.116 What exists are press reports, and they don't agree:

  • Daily Dot, March 2024: quoted Halioua saying the drug would cost $50 to $70 a month if approved, without naming which drug.14
  • Slate, April 2025: reported that Halioua couldn't give an exact price range.13
  • Entrepreneur, May 2026: said LOY-002 could launch for around $100 a month, without saying where the figure came from.15

Budget for the vet too. A prescription drug means an exam first and whatever check-ups your vet recommends.

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

How will owners get Loyal's drugs?

Only through a veterinarian, and only after approval. Loyal says vets will be able to prescribe LOY-002 to qualified dogs if it wins conditional approval. It describes LOY-001 as a prescription injection and LOY-003 as a prescription daily pill.116

Eligibility will be strict. Loyal says its labels will match the dogs studied, and the FDA bans off-label use of conditionally approved drugs, so a vet couldn't prescribe one for a younger or smaller dog.110 Check whether your dog would qualify.

What are the side effects of the dog drug Loyal?

Loyal hasn't published a side-effect list for any of its drugs. For LOY-002, the FDA accepted a safety package that included a standard safety study at one, three and five times the intended dose, with no clinically significant adverse events. It also included field data from about 400 STAY dogs, some treated for up to a year.9

The full details would appear on the label if the drug is approved. Your vet would weigh them against your dog's health and other medications.

Can my dog join a Loyal trial?

Not right now. Loyal's STAY study of LOY-002 is fully enrolled, and it's the only trial on Loyal's clinical trials page.3 Loyal says it will recruit for future studies and points interested owners to its newsletter.31

One other dog aging trial is under way. The Dog Aging Project's TRIAD study is testing rapamycin, a different drug, in dogs 7 and older weighing at least 44 lb, and Tufts, one of its sites, lists a prescreening questionnaire for owners.17 Read more about the Dog Aging Project and rapamycin for dogs.

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

Does Loyal make a drug for cats?

No. Loyal's products and owner pages list programs for senior and large dogs only, and we found no cat program as of November 2026.216 Cats couldn't get Loyal's dog drugs either, because a conditionally approved drug can't be used off its label.10

Our Loyal for cats guide covers what exists for older cats instead.

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

What can I do for my dog while I wait?

The best-supported step costs nothing: keep your dog lean. In a lifelong Purina study of 48 Labradors, dogs fed 25% less than their littermates lived a median of 1.8 years longer.1819 Ask your vet for a target weight before you change portions.

No supplement has been shown to do what Loyal's drugs are being tested for. Our guides to natural alternatives to longevity drugs, diet and dog longevity and anti-aging pills for dogs cover what has evidence. Our dog longevity drugs guide compares every candidate drug.

Where daily nutrition fits

We make Hollywood Elixir, a daily nutrition powder for adult and senior dogs and cats. 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 substitute for Loyal's drugs: 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 daily sachet stirred into food (half for pets under 7 lb, two for dogs over 30 lb) instead of a cupboard of separate supplements. If your dog is in a drug trial or takes a prescription drug, check with your vet before adding it or any other supplement. See the full formula and serving guide.

Loyal hasn't published a price. Press reports range from $50 to about $100 a month.

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

RXE: reasonable expectation of effectiveness, the FDA section showing a drug is likely to work as intended.

Target animal safety (TAS): the FDA section showing a drug is safe in the species it's meant for.

Conditional approval: FDA permission to sell an animal drug for up to five years while full effectiveness evidence is collected. Off-label use isn't allowed.

IGF-1: insulin-like growth factor 1, a growth signal Loyal links to large dogs' shorter lives.

STAY study: Loyal's placebo-controlled study of LOY-002 in about 1,300 senior dogs.

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, confidentiality of active ingredients, publications; checked November 2026)
  2. Loyal, *Products in development* (checked November 2026)
  3. Loyal, *Clinical trials* (STAY design and enrollment; checked November 2026)
  4. Loyal, *About us* (founder, investors and board; checked November 2026)
  5. Loyal via Business Wire (11 Feb 2026), Loyal raises $100M Series C, led by age1, to advance the first canine longevity drug
  6. Loyal (26 Feb 2025), Loyal receives FDA acceptance of reasonable expectation of effectiveness for senior dog lifespan extension
  7. Loyal (28 Nov 2023), Loyal announces historic FDA milestone for large dog lifespan extension drug
  8. Loyal (16 Sept 2026), Longer lives for bigger dogs? Loyal earns third RXE acceptance from the FDA
  9. dvm360 (13 Jan 2026), Lifespan extension drug in development for senior dogs reaches a new milestone
  10. FDA, *Conditional approval explained: a resource for veterinarians* (content current as of 11 May 2026)
  11. 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
  12. Strachan M. Vice (28 Nov 2023). Drug to help dogs live longer has 'reasonable expectation of effectiveness,' FDA says
  13. Hanson K. Slate (23 Apr 2025). This pill from Loyal promises to extend your pet's life, but some experts think that's a bad idea
  14. Bjella B. Daily Dot (9 Mar 2024). 'Dogs are family members': Is your dog the key to living forever?
  15. Small J. Entrepreneur (4 May 2026). This $100-a-month pill can extend the life of your dog
  16. Loyal, *For dog owners* (checked November 2026)
  17. Tufts Cummings School of Veterinary Medicine, *Dog Aging Project: test of rapamycin in aging dogs (TRIAD)*
  18. Kealy RD, Lawler DF, Ballam JM et al. *JAVMA* (2002). Effects of diet restriction on life span and age-related changes in dogs
  19. Lawler DF, Larson BT, Ballam JM et al. *British Journal of Nutrition* (2008). Diet restriction and aging in the dog: major observations over two decades

FAQ

How long will LOY-002 extend a dog's life?

Nobody knows yet. The STAY study is designed to answer that, and Loyal hasn't published lifespan results. In 2023, Vice reported that Halioua told the New York Times the company was aiming for about one extra year.

Is there an anti-aging pill for dogs called Loyal?

Not one you can buy. Loyal is the company, and its pill for senior dogs is called LOY-002. As of November 2026 it isn't approved.

Can I buy Loyal stock?

No. Loyal is funded by private venture investors, and we found no stock-exchange listing or IPO as of November 2026.

Where can I buy LOY-002?

Nowhere yet. It isn't approved and the STAY study is full, so any website offering it now isn't selling Loyal's drug. Once approved, it would be prescribed by vets.

Is LOY-002 the same as rapamycin?

No. Loyal hasn't named LOY-002's active ingredient, but it says the drug works by lowering insulin and improving insulin sensitivity. Rapamycin is a different drug being tested separately in the Dog Aging Project's TRIAD trial.

Will my small dog be able to take LOY-002?

Probably not if your dog is under 14 lb. LOY-002 is being studied in dogs 10 and older weighing 14 to 179 lb, Loyal expects its label to match, and conditionally approved drugs can't be used off-label.

What is the STAY study?

STAY is Loyal's main study of LOY-002. About 1,300 dogs aged 10 and older at 70 US clinics get LOY-002 or a placebo every day for up to four years, and neither owners nor vets know which.

Is LOY-001 FDA approved?

No. The FDA accepted its effectiveness section in November 2023, but its safety and manufacturing sections still have to be accepted before Loyal could seek conditional approval.

Will LOY-002 be available in 2026?

No. As of November 2026 its manufacturing section is still in progress, and Loyal expects the FDA to review it in 2027. A launch would then depend on conditional approval.

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: