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Research / Published Sep 27, 2026 / 4 min read

2026 Mouse Lifespan Retest: Eight Compounds, No Gains

Written by Reviewed Sep 27, 2026

In 2026 the US mouse lifespan testing program retested astaxanthin, meclizine, mitoglitazone, pioglitazone, alpha-ketoglutarate, mifepristone, methotrexate and atorvastatin with telmisartan. None made mice live longer. What changed, and why dose and starting age matter.

Key takeaways

  • The Interventions Testing Program, the US program that tests longevity compounds in mice, tested eleven compounds in this round. None made male or female mice live significantly longer.
  • Astaxanthin, mitoglitazone and meclizine had been linked to longer lives in earlier runs of the program. Given at different doses or started at older ages, they did not help.
  • In female mice, mitoglitazone and pioglitazone were linked to shorter lives. That held after the team set aside one lab whose untreated females lived unusually long.
  • The authors' own lesson is that dose and starting age matter, and one good result at one dose does not carry over.
  • All of this is in mice. None of it was tested in people.

What did the 2026 retest find?

Direct answer

None of the eleven compounds made mice live longer. Three that had been linked to longer lives before, astaxanthin, mitoglitazone and meclizine, did nothing at a different dose or a later starting age. Two diabetes drugs, mitoglitazone and pioglitazone, were linked to shorter lives in female mice. This was all in mice.

The paper is "Astaxanthin, meclizine, mitoglitazone, pioglitazone, alpha-ketoglutarate, mifepristone, methotrexate, and atorvastatin-telmisartan do not increase lifespan in UM-HET3 mice", published in GeroScience in 2026 (PubMed). UM-HET3 mice are bred to be genetically mixed, more like a population of people than one inbred strain. The program runs every test at three labs at once, so one lab's quirk can be spotted and checked.

Each compound, and where to read more

  • Astaxanthin: helped male mice in an earlier run. At a different dose or a later start, no benefit.
  • Meclizine: the motion sickness drug. Also helped male mice in an earlier run, and also showed no benefit this time.
  • Mitoglitazone: linked to longer lives in an earlier run. Started late, it was linked to shorter lives in female mice.
  • Pioglitazone: the approved diabetes drug. Linked to shorter lives in female mice.
  • Alpha-ketoglutarate (calcium AKG is the form sold as a supplement): no benefit.
  • Mifepristone: no benefit.
  • Methotrexate: no benefit.
  • Atorvastatin with telmisartan, a cholesterol drug given with a blood pressure drug: no benefit.

Why a compound can help once and not again

The earlier wins for astaxanthin, mitoglitazone and meclizine were at one dose, started at one age. This round changed the dose or started later, and the benefit was gone. The authors say timing and dose are critical, and that a single result from one site or one group of mice needs caution. The same logic applies when two studies in people disagree: check the dose before deciding which one is wrong.

The female result needed a second look. When all three labs were pooled, astaxanthin, late-start mitoglitazone and pioglitazone all looked harmful for females. But the untreated females at The Jackson Laboratory lived unusually long, which makes any treatment there look worse. With that lab set aside, only mitoglitazone and pioglitazone still looked harmful.

These are mouse results. Pioglitazone is an approved diabetes drug with its own record in people, which is on its page. A shorter life in female mice at this dose is not a finding about people taking it for diabetes.

The bottom line

Eight named compounds, no lifespan gain in mice, and three earlier wins that did not hold up at a new dose or starting age. If a supplement page cites the older mouse result for astaxanthin or meclizine, this is the paper that tested it again.

Frequently asked questions

Does astaxanthin make mice live longer?

Not in the 2026 retest. It had helped male mice live longer in an earlier run of the same program. Given at a different dose or started at an older age, it gave no benefit. All of this is in mice.

Did pioglitazone shorten lifespan in mice?

In female mice, yes. It was linked to shorter lives in the 2026 retest, and that held after one lab with unusually long-lived untreated females was set aside. This is a mouse result, not a finding about people taking pioglitazone for diabetes.

Compound profiles mentioned

Sources

  • Animal study2026

    Astaxanthin, meclizine, mitoglitazone, pioglitazone, alpha-ketoglutarate, mifepristone, methotrexate, and atorvastatin-telmisartan do not increase lifespan in UM-HET3 mice

    In mice. Eleven compounds tested at three sites; none increased lifespan in either sex. Astaxanthin, mitoglitazone and meclizine gave no benefit at new doses or later start ages. With one site set aside, mitoglitazone and pioglitazone were linked to shorter female lifespan.

    GeroScience
  • Animal study2024

    Astaxanthin and meclizine extend lifespan in UM-HET3 male mice; fisetin, SG1002 (hydrogen sulfide donor), dimethyl fumarate, mycophenolic acid, and 4-phenylbutyrate do not significantly affect lifespan in either sex at the doses and schedules used

    In mice. The earlier run in which astaxanthin and meclizine helped male mice live longer.

    GeroScience

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