Meet Kosei:Your human optimization engine.

Longevity as a Service. Apply peer-reviewed research. Monitor your markers. Determine efficacy.

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Kosei brings rigor to longevity.

Most "health advice" is noise — headlines, stacks, and vibes. Kosei is the experimentation app that lets you pull your health data together, pick a real intervention, and see whether it actually moved the needle for you — or didn't.

Ingest data from the sources you already use. Choose what to try. Track the markers that matter. Get a clear read on efficacy across nutrition, training, sleep, supplementation, and whatever else you want to test in the life you already have.

This isn't a clinic. You're not a patient. You're running n=1 on yourself with the science that already exists — so you stop guessing.

Longevity as a service. Your personalized human optimization engine.

Your body already answers.
Most people never ask.

You have more say over how you age than you were told.

See which workouts, foods, and supplements actually work for you.

One paper, n=1, eight to twelve weeks, in the life you already have.

The method

One proven change. Eight to twelve weeks. Your data decides.

  1. 01

    Cite

    The study already ran. We name it. Guessing is the time sink.

  2. 02

    Apply

    One change, eight to twelve weeks, in the life you already have.

  3. 03

    Decide

    Your data says whether it held. Why wouldn't you?

One change, from week one Your data decides. 1 4 8 12
Weeks eight to twelve are the verdict window: the honest length for an n=1. Ours by design, not borrowed from a paper.

Your body's data, synchronized.

Biological age, pace, and the markers you can watch.

Wearables, labs, sleep, meals, movement: one spine.

The science already exists. Apply one proven change in the life you already have — as a participant, not a patient.

Wearables Labs Sleep Meals Movement One spine

Intervention 1 · Sleep

Coach K

Your nights are running under six hours. A short sleep window on the spine is why we cite this paper.

Sleep · Volume 33 · 2010

Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies

Cappuccio · D'Elia · Strazzullo · Miller

1,382,999 adults · 16 prospective cohorts

A meta-analysis of 1.4 million adults found sleeping under six hours associates with 12% higher all-cause mortality.
Cappuccio et al. 2010 — Sleep

Protect a full sleep window: seven to nine hours.

Run it for eight to twelve weeks. Your data decides if it moved you.

The eight-to-twelve-week window is ours, not the paper's. That is the honest length for an n=1.

Intervention 2 · Steps

Coach K

Daily steps sit in the least-active band. Low movement on the spine is why we cite this curve.

Lancet Public Health · Volume 7 · 2022

Daily steps and all-cause mortality: a meta-analysis of 15 international cohorts

Paluch · Bajpai · Bassett · Carnethon

47,471 adults · 15 cohorts · median 7.1 years of follow-up

All-cause mortality, hazard ratio reference: least-active quartile 1.0 0.5 0 0 4,000 8,000 12,000 Median daily steps, by cohort quartile 0.47
Paluch et al. 2022 — Lancet Public Health Illustrative of the paper, drawn from its published quartile medians and hazard ratios. Axes start at zero.

Raise toward the evidence: six to eight thousand steps a day for older adults, eight to ten for younger. Ten thousand was a pedometer slogan, not a finding.

Run it for eight to twelve weeks. Your data decides if it moved you.

The membership

Why wouldn't you?

$99/year

for founding 100 members

Kosei is wellness and self-tracking — not a medical device or a substitute for a clinician.

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Waitlist

$99/year for founding 100 members.

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