Peptide directoryWhole body

Humanin

The first peptide found encoded in mitochondrial DNA, a guard against cell stress.

Where it comes from

Made in
Found in 2001 in the surviving brain of a person with Alzheimer’s disease; made by many tissues and found in blood
Sent out by
Falls with age, and when growth hormone or IGF-1 is given; high in growth hormone-deficient mice
Acts on
  • Neurons
  • Heart and vessel cells
  • Muscle and islet cells
  • Insulin-like growth factor binding protein 3

What it does

  • Protects neurons against amyloid-beta in culture and in mice; it was found in a screen for something that kept cells alive against familial Alzheimer’s genes 1
  • Improves insulin sensitivity in rats when infused into the brain 2
  • A variant (P3S) is enriched among centenarians who carry APOE4, the main genetic risk for Alzheimer’s disease, and clears amyloid better than ordinary humanin in mice 4

In medicine

  • None. Blood humanin is a research marker; it generally declines with age across species, though not in the naked mole rat 3
  • No approved medicine copies it or blocks it, and no analogue has reached a human trial

Beyond the body’s own use

  • HNG, a potent analogue, extended lifespan in worms and improved metabolic healthspan in middle-aged mice, and is studied in mice for Alzheimer’s disease, heart attack and diabetes 3
  • Humanin is promoted as a research peptide for ageing and memory, and people obtain it outside approval. Unapproved and compounded preparations are not reviewed for safety, effectiveness or quality, and there are no efficacy data in people
  • The real human evidence is genetic rather than therapeutic: variants of a peptide encoded inside a mitochondrial ribosomal RNA gene track with living to a hundred 4

Sources

  1. Hashimoto et al., A rescue factor abolishing neuronal cell death by familial Alzheimer’s disease genes and amyloid-beta, PNAS 2001
  2. Muzumdar et al., Humanin, a novel central regulator of peripheral insulin action, PLoS One 2009
  3. Yen et al., The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan, Aging 2020
  4. Miller et al., Humanin variant P3S is associated with longevity in APOE4 carriers, Aging Cell 2024

This card describes what a medicine is for and what the evidence says; it recommends nothing. Talk to your clinician about anything you read here.