TruDiagnostic built a CLIA methylation lab and biobank whose epigenetic clocks power both consumer testing and academic research, and Tally Health (now under TruDiagnostic's parent) sells at-home epigenetic-age tests from the Sinclair lineage. Industrializing the assay improves precision and reproducibility, but a stable, well-run clock still inherits the field's open question: what a 'younger' epigenetic age actually predicts for that individual's health.

Generation Lab's SystemAge scores aging across 19 physiological systems from a blood sample, and organ-clock work from the plasma proteome (the Stanford/Wyss-Coray lineage) reads the differential age of heart, brain, and kidney. Decomposing 'age' into systems is more actionable than a single number, but it multiplies the validation burden — each sub-clock needs its own outcome data.

Function Health pairs 100+ blood biomarkers with whole-body imaging and an AI interpretation layer, betting that breadth plus longitudinal tracking substitutes for a single validated clock. It generates a rich individual baseline, but risks incidental findings and correlation-without-causation — a dashboard of numbers is not yet a proof that intervening on any of them extends life.

Life Biosciences uses a three-factor OSK cocktail (dropping the oncogenic c-Myc) delivered transiently and locally to the eye — a compartment where dosing can be contained — and won the first FDA clearance to test it in humans. Restricting the factors, the tissue, and the exposure window is the leading safety strategy, but the first human data (post first-dose, June 2026) is exactly what will show whether the margin holds outside a mouse.

NewLimit screens novel transcription-factor combinations delivered by LNP to rejuvenate liver cells, and Shift Bioscience uses AI aging clocks to hunt single-gene factors that reset age without dedifferentiation at all. Moving beyond the classic Yamanaka factors aims to widen the safety window by design — but a factor that rejuvenates without ever risking pluripotency is still a hypothesis, not a validated drug.

Retro Biosciences, in partnership with OpenAI, reported AI-designed factors that made reprogramming ~50× more efficient, and chemical-cocktail approaches aim to avoid genetic modification entirely. Higher efficiency and non-genetic delivery could improve control and manufacturability, but efficiency is not safety — a faster reset can also reach the danger zone faster.

The TAME trial, led by Nir Barzilai, was designed to win FDA acceptance of a composite endpoint — delaying the onset of multiple age-related diseases at once — as proof that aging is treatable. The FDA reportedly blessed the concept years ago, but metformin's generic status left the trial chronically underfunded; the endpoint template exists on paper without the trial to prove it.

Companies building epigenetic and proteomic clocks (TruDiagnostic, BioAge's human-data platform) are trying to establish a biomarker that moves with intervention and predicts outcomes, which could serve as a surrogate endpoint. The bar is high: a surrogate has to be validated against hard outcomes before a regulator will accept it, and no aging clock has cleared that bar.

Life Biosciences runs its reprogramming drug in glaucoma and NAION, BioAge attacks obesity and cardiovascular inflammation, and Vandria targets specific mitophagy-linked diseases — winning approval on conventional endpoints and letting the aging mechanism ride underneath. It is the pragmatic path to market, but it defers the actual question of whether aging itself can be an indication.

Rubedo Life Sciences designed RLS-1496 as a GPX4 modulator that sensitizes ferroptosis-prone pathologic senescent cells specifically, reporting positive preliminary Phase 1 data in skin and target engagement in photo-aged tissue. Aiming at a vulnerability enriched in harmful senescent cells is more precise than broad senolysis — but proving that precision holds beyond skin, in a disease-modifying trial, is the open test.

Cleara Biotech develops FOXO4-derived senolytic peptides intended to selectively trigger death in senescent cells with disrupted p53 signaling. Peptide targeting can encode more specificity than a small molecule, but delivery, stability, and demonstrating a real therapeutic window in humans remain unsolved for the modality.

Deciduous Therapeutics activates iNKT immune cells to clear senescent cells, and Oisin Biotechnologies delivers gene-directed payloads via non-viral lipids to destroy them. Recruiting the immune system or gene logic could add a layer of selectivity the body itself uses — but it also adds the risk of over-activation and off-target clearance, and neither approach has yet shown durable human benefit.

The LEV Foundation's Robust Mouse Rejuvenation program combines four-plus interventions known to individually extend mouse lifespan, betting that additive damage-repair in the strongest possible mouse model is the honest proof-of-concept before human translation. RMR1 produced a 'qualified win'; the harder question — whether an additive mouse result survives the jump to a longer-lived species — is what RMR2 and everything downstream must answer.

Loyal runs FDA-track lifespan trials in companion dogs, which age ~7× faster than humans, share our environment, and permit a real lifespan endpoint within a few years — a genuine intermediate between mouse and human. It compresses the timeline and generates regulatory precedent, but veterinary approval does not legally transfer to humans, and dog biology is its own gap.

BioAge and Gero start from human aging cohorts and physics-based human models rather than mouse screens, nominating targets already grounded in human biology to skip the worst of the translation gap. Beginning in humans reduces species risk in principle, but the resulting drugs (BioAge's azelaprag setback, then its NLRP3 and APJ programs) still have to survive human trials — the gap narrows, it does not close.

Until Labs is pursuing reversible whole-body cryopreservation but starting where the payoff is nearest and testable — reversible preservation of organs for transplant, which would relieve the donor-organ shortage and validate the underlying cryobiology. Proving one organ recovers function after vitrification and rewarming is the credible near-term milestone; whole-body reversal remains far beyond it.

Alcor, the Cryonics Institute, Tomorrow Bio, and Southern Cryonics preserve legally deceased patients at cryogenic temperature on the premise that future medicine can revive and repair them. It is a preservation service, not a demonstrated revival technology — the operational challenge is minimizing damage at the moment of preservation, since nothing not preserved can ever be recovered.

Advances in cryoprotectant chemistry and controlled vitrification aim to reduce ice damage and toxicity across larger tissue volumes — the shared technical bottleneck for both transplant preservation and cryonics. Progress here is incremental and measured in tissue types successfully recovered, and scaling from small tissues to organs to bodies is a steep, unproven climb.