Research explainer by BDS Animal Health. Sources checked 13 October 2026.
Hero image: original AI-generated illustration created with ChatGPT. It does not show an actual STAY trial participant.
Could a daily tablet help older dogs live longer while staying well? That is the question behind LOY-002, an experimental dog longevity drug being developed by Loyal. Sometimes described as an anti-ageing pill for dogs, it is being tested in the STAY clinical trial in companion dogs living with their families.
The research is worth following, but the distinction between a promising drug candidate and a proven treatment matters. As of 13 October 2026, Loyal's published development tracker still lists manufacturing review, conditional FDA approval and market availability as in progress. The milestones discussed below are steps in development, not an announcement that LOY-002 is approved or available.
What is LOY-002 being developed to do?
Loyal describes LOY-002 as a daily oral medicine intended for dogs aged 10 years and older weighing at least 14 lb, approximately 6.4 kg. Its proposed approach targets age-associated metabolic dysfunction, including insulin regulation, with the aim of extending healthy lifespan. That remains a development goal; it does not tell us how much longer an individual dog might live.
The company's 26 February 2025 announcement sets out this intended population and rationale. These study criteria should not be read as prescribing advice, or as evidence that the medicine would suit every dog in that age and weight range.
A peer-reviewed study published on 13 February 2025 examined 451 adult companion dogs. Higher insulin levels were associated with greater frailty and poorer health-related quality of life. The cross-sectional study, by Loyal-affiliated researchers, helps explain the biological question. It did not test LOY-002 or prove that lowering insulin extends life. Controlled treatment studies are needed to establish whether the proposed approach works.
What is the STAY trial actually testing?
On 14 July 2025, Loyal announced that STAY had finished enrolment, reporting 1,300 dogs and 72 participating veterinary clinics across the United States. Its current overview summarises the scale as 1,300-plus dogs across 70 practices. Full enrolment is an important operational milestone, rather than a finding about whether the drug works.
According to the official study description, STAY compares lifespan, health and quality of life in dogs receiving LOY-002 with those receiving a placebo. Participation is designed to span up to four years.
The trial is placebo-controlled and double-blinded. Some dogs receive a tablet without the active drug, and treatment allocation is concealed during the study. This helps researchers distinguish a treatment effect from other differences or expectations. Owners also complete quality-of-life surveys, alongside veterinary study visits.
What have the FDA milestones established?
Two dates help put the headlines in order:
- 26 February 2025: Loyal announced FDA acceptance of LOY-002's Reasonable Expectation of Effectiveness technical section, often shortened to RXE.
- 13 January 2026: Loyal announced acceptance of its Target Animal Safety section. Its veterinary information page dates completion of that safety package to December 2025.
The safety announcement describes laboratory testing and field safety information from hundreds of dogs. This is meaningful progress in assessing the proposed use. It does not establish zero risk, replace a final product label or demonstrate a completed lifespan benefit.
The FDA explains that conditional approval requires a reasonable expectation of effectiveness, while full approval requires substantial evidence of effectiveness. Both require the drug to meet applicable safety requirements. If granted, conditional approval can allow sale for labelled uses while the remaining effectiveness evidence is collected. Acceptance of individual technical sections does not itself grant that approval.
What evidence is still missing?
The sources reviewed for this article do not provide completed STAY results establishing a lifespan extension. Loyal continues to describe STAY as an ongoing effectiveness study intended to support full approval. A claim that LOY-002 has already been shown to add a particular number of years to dogs' lives would therefore go beyond the evidence presented here.
When results become available, useful questions will include:
- How large was any difference between the treatment and placebo groups?
- How certain were the estimates, and how many dogs completed follow-up?
- Were quality of life and health outcomes improved as well as survival?
- What adverse effects occurred, and which dogs were represented?
Company announcements report the developer's progress. Independent assessment of the full methods and results will be important when judging any eventual benefit.
How does this relate to senior dog supplements?
LOY-002 is being developed through a veterinary drug pathway. Its research does not establish lifespan benefits for senior dog supplements or products advertised as anti-ageing supplements for dogs. Evidence needs to match the particular product and outcome being claimed.
What should Australian dog owners take from this?
The study and milestones concern a US development programme. They do not establish Australian registration, availability or a local launch date. We could not verify an Australian registration or launch date for LOY-002 in the sources reviewed. Australian veterinary medicines are regulated separately by the APVMA, which provides a registered products and permits search. For senior dog care decisions, speak with a registered veterinarian who knows your dog's health history and current medicines.
For now, LOY-002 is a research programme to watch carefully. The most useful next developments will be a formal regulatory decision and transparent clinical results, rather than a promise of extra years.
Editorial note: This article summarises publicly available research and regulatory information; it is not original clinical research or individual veterinary advice. No longevity benefit is claimed for BDS products.
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