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Head-to-head

Humanin vs Klotho

Two 'longevity proteins' whose biology is genuinely compelling and whose supplement market is entirely aspirational — neither has a validated way to actually raise your own levels.

By Julian RothResearch & dataUpdated October 2026

Short answer

Neither humanin nor klotho has much human evidence; both are graded preclinical / minimal, so trials cannot say which works better. Humanin is the one sold for longevity and metabolic health, while klotho targets longevity and cognitive and kidney health.

Humanin

Preclinical / minimal

A genuine cytoprotective mitochondrial-derived peptide whose levels fall with age — but no randomized human trial shows that taking it does anything for people.

Full Humanin evidence review

Klotho

Preclinical / minimal

The foundational biology is real and compelling — mice lacking klotho age rapidly, mice overexpressing it live longer — but there is no validated oral supplement that raises human klotho levels, so the entire human case is aspirational.

Full Klotho evidence review

Humanin vs Klotho: head to head

FDA status / approved use

Humanin

Not approved for any use; sold as an unregulated research injectable

Klotho

Not an available therapy; products sold as klotho supplements or boosters are not validated
Marketed for

Humanin

Longevity, metabolic health

Klotho

Longevity, cognitive and kidney health
Outcome areas

Humanin

Longevity / lifespan; Mitochondrial / cellular energy

Klotho

Longevity / lifespan; Cognitive function / memory
Evidence grade

Humanin

Preclinical / minimal

Klotho

Preclinical / minimal
How it works

Humanin

Mitochondrial-derived peptide that blocks cell death in lab and animal studies

Klotho

Circulating hormone that dampens insulin and IGF-1 signaling
Route and dosing

Humanin

Injection

Klotho

No oral form; injected protein in animal research only
Headline human result

Humanin

Not established

Klotho

Not established
Strongest evidence

Humanin

Hashimoto, PNAS 2001. Little or no controlled human outcome data for the marketed useHumanin evidence reviewPubMed 11371646

Klotho

Kuro-o 1997 founding mouse study, Nature. Little or no controlled human outcome data for the marketed useKlotho evidence reviewPubMed 9363890
Key safety signal

Humanin

Identity, dose, purity and sterility unverified; no long-term human safety data

Klotho

No validated oral product exists; taking klotho is untested in people
How it is obtained

Humanin

Sold gray-market as a research chemical; no approved or legitimately compounded human product

Klotho

Not established

marks a row where the two differ. “Not established” marks a cell the available evidence does not answer. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.

Preclinical / minimal:
Evidence is largely animal, in-vitro, or anecdotal. Little or no controlled human outcome data for the marketed use.

Our verdict

Klotho's founding science is dramatic: mice lacking it age rapidly, mice overexpressing it live longer — but there's no oral supplement shown to raise human klotho levels, so 'klotho supplements' are selling a name, not the mechanism. Humanin is a genuine mitochondrial-derived peptide whose levels fall with age and which shows cytoprotective effects in cell models, but no randomized human trial shows that taking it does anything for people. Both pages exist mainly to explain real biology that has, so far, produced no real product.

Humanin fits if

You're interested in mitochondrial-signaling peptides specifically — same caveat: real mechanism, zero human outcome data behind anything sold under this name.

Klotho fits if

You're interested in the aging-clock biology specifically — read this as science, not as a shopping guide.

Humanin vs Klotho: common questions

Is either humanin or klotho FDA-approved?
No. Humanin is not approved for any use; sold as an unregulated research injectable. Klotho is not an available therapy; products sold as klotho supplements or boosters are not validated.
Which has stronger human evidence, humanin or klotho?
Neither. Both are graded preclinical / minimal, with little or no controlled human outcome data for the marketed use. The key source for humanin is Hashimoto, PNAS 2001; for klotho, it is Kuro-o 1997 founding mouse study, Nature.
What are the main safety concerns with humanin and klotho?
For humanin, watch for unverified identity, dose, purity and sterility; no long-term human safety data. With klotho, no validated oral product exists; taking klotho is untested in people.

Key studies behind each

Humanin

  1. Hashimoto Y, Niikura T, Tajima H, et al. (2001). A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta. Proc Natl Acad Sci U S A. PubMed 11371646
  2. Muzumdar RH, Huffman DM, Atzmon G, et al. (2009). Humanin: a novel central regulator of peripheral insulin action. PLoS One. PubMed 19623253
  3. Yen K, Mehta HH, Kim SJ, et al. (2020). The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan. Aging (Albany NY). PubMed 32575074
  4. Lee C, Yen K, Cohen P. (2013). Humanin: a harbinger of mitochondrial-derived peptides? Trends Endocrinol Metab. PubMed 23402768

Klotho

  1. Kuro-o M, Matsumura Y, Aizawa H, et al. (1997). Mutation of the mouse klotho gene leads to a syndrome resembling ageing. Nature. PubMed 9363890
  2. Kurosu H, Yamamoto M, Clark JD, et al. (2005). Suppression of aging in mice by the hormone Klotho. Science. PubMed 16123266
  3. Arking DE, Krebsova A, Macek M Sr, et al. (2002). Association of human aging with a functional variant of klotho. Proc Natl Acad Sci U S A. PubMed 11792841
  4. Dubal DB, Yokoyama JS, Zhu L, et al. (2014). Life extension factor klotho enhances cognition. Cell Rep. PubMed 24813892

The full evidence reviews

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