Longevity supplements: what the evidence supports

Written by Steve Fayzulayev. Clinically reviewed by Naomi Fayzulayev, FNP-C, MSN.

Last reviewed 2026-11-09. See our editorial policy and methodology.

Almost everything sold for longevity is supported by mouse data, mechanism, or a short trial measuring a surrogate marker. That is not the same as evidence that it extends healthspan in people, and the gap is where most of the money goes.

A grading that is actually usable

Tier A means human randomised trials with clinical or robust surrogate endpoints, replicated. Tier B means human trials with surrogate endpoints only, or mixed results. Tier C means mechanism, animal data, or observational association without a trial.

Almost every compound marketed as an anti-ageing breakthrough is Tier C. That does not make it useless; it makes it a bet, and the sums involved should reflect that.

The strongest cases are corrections, not enhancements

Vitamin D if you are deficient, B12 if you are deficient or on long-term metformin, iron if you are depleted, omega-3 if your index is low, creatine for muscle and probably cognition. These share a structure: they fix a measurable shortfall and the benefit disappears once you are replete.

This is the least exciting category and the one with the best evidence. It is also the only one where testing first is genuinely worth the cost, because the answer changes what you take.

The popular ones, honestly

Resveratrol produced striking results in yeast and mice and has repeatedly failed to replicate in humans. NMN and NR raise NAD+ levels measurably — that part is real — but trials to date have not translated that into clinical benefit, and the supplement industry moved on to selling the surrogate as though it were the outcome.

Metformin and rapamycin are the two compounds with the most serious longevity case, and both are prescription drugs with real side-effect profiles, under active trial. Neither is a supplement, and the people taking them off-label are running an experiment with no control group.

Collagen, greens powders and most antioxidant blends have essentially no outcome evidence. High-dose antioxidants can blunt the adaptive response to exercise, which is an example of a supplement working against the intervention that does have evidence.

What to spend on instead

The interventions with the strongest evidence are not purchasable: sleep, resistance training, aerobic base, not smoking, alcohol reduction, and keeping visceral fat down. They are free, unglamorous, and outperform every supplement on this page by a wide margin.

If you have a budget, the highest-return purchase is usually measurement rather than compounds — knowing your ApoB, Lp(a), fasting insulin and omega-3 index changes what you do, where another bottle generally does not.

A conflict worth stating

Supplement affiliate revenue is the obvious way to monetise a site like this, and it is the reason to be suspicious of grading like this anywhere it appears. This site does not take supplement commission, specifically because a grade that pays more when it is higher is not a grade.

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Frequently asked questions

Do longevity supplements work?

Almost everything sold for longevity is supported by mouse data, mechanism, or a short trial measuring a surrogate marker. That is not the same as evidence that it extends healthspan in people, and the gap is where most of the money goes.

What does this guide cover?

This guide covers: A grading that is actually usable; The strongest cases are corrections, not enhancements; The popular ones, honestly; What to spend on instead; A conflict worth stating.

All guides

Not medical advice. These are longevity-optimised reference ranges, which are deliberately stricter than standard clinical "normal" values. A value outside them does not mean you have a disease. Speak to a qualified healthcare professional before changing medication, supplements or training. Full disclaimer.
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Do longevity supplements work?

Almost everything sold for longevity is supported by mouse data, mechanism, or a short trial measuring a surrogate marker. That is not the same as evidence that it extends healthspan in people, and the gap is where most of the money goes.

What does this guide cover?

This guide covers: A grading that is actually usable; The strongest cases are corrections, not enhancements; The popular ones, honestly; What to spend on instead; A conflict worth stating.

What is biological age?

Chronological age counts birthdays. Biological age estimates how old your body appears to be functioning, based on measurable biomarkers. Two people born the same year can differ by a decade or more in vascular stiffness, insulin signalling or cardiorespiratory fitness. Biological age makes that gap explicit — and unlike your birthday, it can move in either direction.

How is the Longevity Score calculated?

Each biomarker you enter is scored against longevity-optimised reference ranges and grouped into one of eight dials. Every dial produces its own biological age, and those are combined using fixed weights into a single composite, then expressed as a Longevity Score from 0 to 100. The weighting reflects how strongly each system predicts healthspan: structural and vascular carry the most, hormonal the least.

Do I need all 53 biomarkers?

No. The short form contains a subset of scoring inputs plus context-only fields, and you can leave any of them blank. It is not a recommendation to obtain tests. Missing values are excluded from the calculation — never treated as zero or as 'normal'. A dial with no scored data is dropped entirely and the remaining weights renormalise.

What can I measure without a blood test?

Some inputs can be measured without bloodwork. Blood pressure needs a home cuff and waist-to-height needs a tape measure. Wearable estimates vary; the floor-based sitting-rising test carries a fall risk and should only be attempted if safe.

Is this an anti-aging calculator? Is it a healthspan calculator?

Both terms describe what this tool does, and which one fits depends on what you are asking. "Anti-aging" is the term most people search, and loosely means anything aimed at slowing or reversing age-related decline — this tool fits that description if you score your dials and act on what you find. "Healthspan calculator" is the more precise term: healthspan is the number of years lived without serious chronic disease or disability, and that cannot be measured directly, so this tool scores eight systems that each function as an early-warning proxy for it. Either way, the method is the same: real biomarkers, published thresholds, no vanity-metric framing.

Why don't you have a quick quiz that skips biomarkers entirely?

Several popular tools ask only about habits — exercise days, sleep hours, smoking, diet quality — and return a single precise-looking age. We looked at the research behind that approach and chose not to build it. Published studies do show real, individually-measured links between specific habits and epigenetic age acceleration, but those effect sizes come from different study populations, different DNA-methylation clocks and different measurement units. Adding them together into one number is not something the underlying research actually supports — it produces a precise-looking result built on an imprecise method. Our dials use direct physiological measurements instead: a real blood pressure reading, a real VO₂ max, a real ApoB value. Several dials score from home-measurable data alone with no quiz-guessing involved — see what you can measure without a blood test, above.

Why are your 'optimal' ranges stricter than my lab's normal range?

Standard reference ranges describe what is common in a general population, which now includes a great deal of metabolic dysfunction. They are tuned to flag disease, not to identify what is optimal for a long healthspan. A fasting insulin of 20 µIU/mL sits inside most labs' normal range and is strongly associated with insulin resistance. This tool uses longevity-optimised thresholds instead, so a flag here means room for optimisation — not a diagnosis.

Why not just upload my labs to ChatGPT?

For understanding a single result, do — a frontier chat model is genuinely good at that, often clearer than most medical sites, and it handles markers no fixed tool covers. The limitation is different from the one most people assume. A language model produces a plausible response rather than a computed one, so the same panel can score differently on different days. That is fine when exploring an idea and disqualifying when measuring change, because you cannot tell how much of a difference is you and how much is the method. Use both: a chat model to understand, a fixed instrument to track.

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