α-Klotho, longevity-associated protein
Klotho
Cited range Preclinical
What it is
α-Klotho is a protein named after the Greek fate who spins the thread of life. In mice, disrupting the gene produces a rapid aging-like phenotype, and overexpressing it extends lifespan — which is why it became a fixture of longevity discussion. A soluble form is shed into blood and acts as a circulating factor. It is a large protein, not a short synthetic peptide.
Benefits in plain language
What researchers and reference users usually mean when they talk about this compound. These are study themes and common claims — not a promise that it will do this in you.
- Klotho is one of the few molecules with genuine mouse longevity data — removing it accelerates aging, adding it slows some aging markers.
- It regulates phosphate and vitamin D through FGF-23, so its effects are partly metabolic housekeeping.
- In humans, higher circulating Klotho correlates with better cognition and healthspan in observational studies.
- Correlation is not causation: nobody has shown that giving Klotho protein to people extends life.
If a branded, FDA-approved product exists, that label is the only dose that is actually authorized. Research-chemical vials are a different object.
Mechanism of action
Membrane Klotho acts as a co-receptor for FGF-23 (regulating phosphate excretion) and FGF-21 in some tissues. The shed soluble form has been reported to modulate Wnt, IGF-1, and NRF2 signaling, reduce oxidative stress, and influence calcium channel trafficking. Several of these mechanisms remain contested.
Possible side effects / caveats
No human safety data for administration of Klotho protein exist. It is a large glycoprotein with poor oral bioavailability and short circulating half-life. Concerns include unintended phosphate or mineral effects and the general risk of chronically modulating growth and metabolic signaling. Material sold as "Klotho peptide" is almost certainly a fragment with none of the studied biology.
Protocol ranges
| Source tier | Amount | Frequency / duration | Notes |
|---|---|---|---|
| Preclinical papers | Gene delivery or protein in mice | Model-dependent | No human dose established |
| Cited range | No accepted human protocol | — | "Klotho peptide" products are unvalidated fragments |