Targeting Ageing as a Disease:
Geroscience, the TAME Trial and the Regulatory Debate

Medicine usually treats one disease at a time: a statin for cholesterol, a pill for blood pressure, chemotherapy for cancer. But as the American Federation for Aging Research puts it, "aging itself is by far the greatest risk factor for most of the chronic diseases and disabilities which affect older adults". Geroscience is the field built on a simple idea: if we can slow the biology of ageing, we could delay many diseases at once. Turning that idea into medicine faces a major obstacle: regulators don't recognise ageing as a condition that drugs can be approved to treat. The TAME trial (Targeting Aging with Metformin) was designed to change that by testing whether the cheap diabetes drug metformin delays heart disease, cancer, dementia and death together in 3,000 people aged 65-79. But because metformin is a generic drug, the trial has struggled to raise the $45-70 million it needs. The language matters too: the World Health Organization added "old age" to its disease classification and then replaced it after criticism, stressing that it isn't classifying ageing as a disease. Meanwhile, the first progress may come in dogs: in 2025, the US FDA accepted that a pill for senior dogs had a "reasonable expectation of effectiveness" for extending lifespan. This article explains the geroscience idea and the obstacles to making it medicine.

Key numbers

The discovery: the geroscience idea

Geroscience aims to "understand how aging enables diseases and to exploit that knowledge to slow the appearance and progression of age-related diseases and disabilities". Its central hypothesis is that, because the same underlying biology, the hallmarks of ageing, drives many chronic diseases, targeting that biology could "delay the onset of multiple diseases at once" (see The Hallmarks of Ageing).

This matters because older adults rarely have just one disease. Treating heart disease alone might add a few years before another condition, such as cancer or dementia, takes hold. Slowing ageing itself could, in theory, compress the period of illness at the end of life.

What the research shows

Animal evidence. Many interventions extend healthy lifespan in animals, including calorie restriction, rapamycin and clearing senescent cells (see Nutrient-Sensing Pathways and Senolytics). In these animals, the treatments delay several age-related diseases together, supporting the geroscience hypothesis.

The TAME trial. TAME, led by Nir Barzilai of the Albert Einstein College of Medicine, was designed as a proof of concept. Rather than measuring one disease, it would test whether metformin delays the onset of a group of age-related conditions, including heart disease, cancer and cognitive decline, in about 3,000 people aged 65-79 over six years. Success could persuade the FDA to accept "ageing" or delaying multiple diseases as a legitimate target for drug development.

Metformin was chosen because it's cheap, has decades of safety data and affects several ageing pathways in animals. But because it's off-patent, no company stands to profit, and funding has been a persistent problem: the trial was estimated to cost $45-70 million, with only about $5 million from the National Institute on Aging. In September 2026, one report described TAME as "the aging trial that never enrolled a patient". Other studies have also raised questions about metformin in healthy older adults, including a trial in which it blunted muscle gains from strength training (see Longevity Supplements).

The language of ageing: WHO's classification. In its latest International Classification of Diseases (ICD-11), the WHO replaced the old term "senility" with "old age", a change criticised by many experts as implying that being old is a disease. After a stakeholder proposal, the term was changed again to "ageing-associated decline in intrinsic capacity". The WHO emphasises that it is "not classifying aging as a disease"; the category exists mainly to help code unclear statements on medical records and death certificates.

Dogs may come first. In the US, Loyal is developing drugs specifically to extend dogs' healthy lifespan. The FDA accepted a "reasonable expectation of effectiveness" for LOY-001, an injection for large dogs, in November 2023, and for LOY-002, a daily pill for dogs aged 10 and over, in February 2025. Full approval still requires safety and manufacturing data. The STAY study, described as the largest veterinary clinical trial in history, is testing LOY-002 against placebo in 1,000 senior dogs across about 70 clinics over four years, measuring both lifespan and quality of life. If approved, it would be the first drug with a lifespan-extension indication for any species.

Where it stands: promise vs risks

The challenges include defining measurable outcomes for "slowing ageing" in people, the cost and length of trials that must follow people for years, the lack of commercial incentives for generic drugs, and ethical concerns about labelling a universal human experience as a disease. Biomarkers such as epigenetic and proteomic clocks might eventually serve as earlier endpoints in trials, but they aren't yet accepted for this purpose (see Epigenetic Clocks Explained).

Why this matters for longevity

Geroscience could reshape medicine: from managing diseases one by one to preventing them together by targeting their common root. But the path from animal studies to approved human treatments is long, and it depends as much on regulation, funding and trial design as on biology. The first approved "longevity drug" may well be for dogs, and the lessons from that process could open the door for humans.

Practical notes

There are currently no drugs approved to slow human ageing. Metformin, rapamycin and similar drugs should only be used for their approved indications or within research. Doctors increasingly take a "geroscience-informed" approach in practice, focusing on interventions that reduce the risk of several diseases at once: regular exercise, a healthy diet, not smoking, good sleep, and controlling blood pressure, cholesterol and blood sugar. These are, in effect, today's proven "anti-ageing" treatments (see Eating Patterns for Longevity). Our Longevity Doctors take this whole-person approach, starting with the free longevity assessment.