How close are we to extending healthy human lifespan?Can we stay healthy for much longer?
or, simply: Can we stay healthy for much longer?or, precisely: How close are we to extending healthy human lifespan?
Multiple interventions now reproducibly slow aging in mice, but no treatment has yet shown a large, durable extension of healthy lifespan in humans.We can slow parts of aging in animals; proving that people gain many healthy years will take long, careful trials that are only just starting.
We are here
First partial reprogramming dosed in a human (ER-100) — Life Biosciences dosed the first patient in a Phase 1 trial of ER-100, an OSK partial-reprogramming therapy injected into the eye — the first reprogramming therapy to reach humans. Next up — ER-100 Phase 1 safety readout (expected 2027).
01 · Where we stand
Four tests between here and the goal
Each threshold is a falsifiable claim with a named next test. We move the meter only when a result is public.
Slow aging in mammalsAdd healthy time to an animal's life✓ Achieved · 2009
100%
Proven byNIA Interventions Testing Program: rapamycin extends mouse lifespan, later replicated many times
Validated aging biomarkersMeasure aging before decades passEarly
30%
Next testRegulatory qualification of DunedinPACE-class clocks as surrogate endpoints in interventional trials
Human healthspan efficacyKeep people healthier for longerEarly
12%
Next testVITAL-H Phase 3 (726 adults, 3 repurposed drugs) and larger geroscience trials with clinical outcomes
Safe human rejuvenationRepair old tissue safelyEarly
6%
Next testLife Biosciences ER-100 Phase 1 safety and visual-function readout in optic neuropathy
THRESHOLDS — Thresholds for Healthy Longevity.
Scale
Measured Goal region
NOTE — All results are in mice and NONE are validated in humans; the effects are also strongly sex-dependent.
02 · How we got here
The record behind the verdict
Major events set large; context events set small but never hidden. Everything below the TODAY rule is a schedule, not a result.
Dietary and genetic foundations begins with calorie restriction extends rat lifespan. The result established the next question for the field.
1935
Calorie restriction extends rat lifespan
Clive McCay showed that restricting rats' food intake (without malnutrition) raised maximal lifespan by roughly a third, the founding result of aging-intervention research.
Pathways and drugs moved the field from a single-gene mutation doubles worm lifespan to telomerase gene therapy extends mouse lifespan. The results narrowed the next question without closing it.
1993
A single-gene mutation doubles worm lifespanExperiment
Cynthia Kenyon reported that a daf-2 mutation more than doubled the lifespan of the worm C. elegans, proving in worms that aging is genetically regulated.
The National Institute on Aging launched a rigorous multi-site program to test whether candidate drugs extend lifespan in genetically diverse mice using standardized, replicated protocols.
A lab reported resveratrol improved survival of mice on a high-calorie diet, igniting the sirtuin/resveratrol wave and a $720M biotech acquisition (in mice).
The NIA ITP showed the mTOR inhibitor rapamycin extended lifespan of genetically heterogeneous mice even when started in old age — the first drug to do so in a rigorous replicated test (in mice).
Resveratrol fails to extend lifespan in rigorous test
The same ITP that validated rapamycin found resveratrol did not extend mouse lifespan; the mechanism was disputed and GSK later shut the Sirtris program — a cautionary tale of overpromising.
Cellular rejuvenation moved the field from partial reprogramming rejuvenates cells in living mice to first-in-human senolytic trial. The results narrowed the next question without closing it.
2016
Partial reprogramming rejuvenates cells in living mice
Cyclic, short-term expression of Yamanaka factors reversed hallmarks of aging and extended lifespan in progeroid mice, founding the cellular-rejuvenation field (in mice).
The dasatinib-plus-quercetin senolytic combination selectively cleared senescent cells, improved physical function, and extended lifespan in naturally aged mice (in mice).
A first-in-human open-label pilot gave dasatinib and quercetin to 14 patients with pulmonary fibrosis, showing feasibility and improved mobility (small early-stage human trial, no control group).
Human translation moved the field from reprogramming companies launch on billionaire funding to er-100 phase 1 safety readout. The results narrowed the next question without closing it.
2022
Reprogramming companies launch on billionaire funding
Altos Labs debuted with roughly $3B, alongside Retro Biosciences and Life Biosciences, industrializing cellular reprogramming and senescence research toward human therapies.
Calorie restriction slows a validated aging clock in humansExperiment
The randomized CALERIE trial found 2 years of 25% calorie restriction slowed DunedinPACE, a DNA-methylation pace-of-aging measure, by 2-3% in healthy adults — an early human signal.
First partial reprogramming dosed in a human (ER-100)DeploymentWe are here
Life Biosciences dosed the first patient in a Phase 1 trial of ER-100, an OSK partial-reprogramming therapy injected into the eye — the first reprogramming therapy to reach humans.
The first human safety and tolerability data for partial epigenetic reprogramming are expected — a pivotal test of whether the mouse rejuvenation results translate to people.
Events outside the declared eras begins with target: a phase 3 healthspan endpoint (tame). The result established the next question for the field.
2030
Target: a Phase 3 healthspan endpoint (TAME)ExperimentTarget
The proposed TAME trial would test whether metformin delays a composite of age-related diseases in 3,000 older adults, seeking the first regulatory proof that a drug can target aging.
The learning curves and comparisons that justify each threshold's percentage. Every series is measured, with the source event linked in the timeline above.
Mouse lifespan gains
Drugs are climbing, but the anchor is higher
+24%points still to goal
MICE ONLY — All results are in mice and NONE are validated in humans; the effects are also strongly sex-dependent.
04 · What it unlocks
If the remaining tests pass
Downstream capabilities, drawn dashed because they depend on results not yet in.