Longevity
Humanin
aka HN · HNG (S14G-Humanin, a more potent analogue) · Mitochondrial-derived peptide (MDP) · MTRNR2 · humanin · humanin peptide
Grade
A tiny protective peptide your own mitochondria make, which looks fascinating in lab animals and correlates with healthy ageing in people, but has never been properly tested as a drug in humans.
- Class
- Mitochondrial-derived peptide (MDP); endogenous 24-amino-acid cytoprotective peptide
- Evidence
- Grade D · Animal data only
- Last reviewed
- 2026-06
Grade D · Animal data only
Why this grade
Humanin is a real, well-characterised endogenous peptide with a large preclinical literature (cell and rodent studies) and intriguing human OBSERVATIONAL data: higher circulating levels track with longevity and better cognitive ageing. But there are no completed interventional human trials of administered humanin (or its analogues) demonstrating clinical benefit, and its human pharmacology is essentially uncharacterised. As a therapeutic given to people, the human efficacy evidence is negligible, which puts it firmly at D rather than C. The observational human correlations are interesting biology, not proof that injecting it helps.
What is it?
Inside every cell are little power plants called mitochondria. Scientists found that they also make a tiny protein called humanin that seems to protect cells from dying when they're under stress. In lab dishes and in mice it can shield brain cells, calm down damage and even help mice live a bit longer and stay sharper. People who naturally have more of it in their blood tend to live longer and age better. That sounds exciting, but here's the honest catch: nobody has ever run a proper trial of giving humanin to humans to see whether it actually makes them healthier. So right now it's a promising lab story, not a proven treatment.
It's like discovering that people who naturally produce more of a certain repair enzyme tend to live longer (genuinely interesting biology), and then a shop starts selling vials of that enzyme claiming it'll extend your life, even though nobody has ever run the trial to see what happens when you actually take it. The native peptide is real and protective; the bottle on the shelf is a leap of faith.
How is it meant to work?
Humanin is an endogenous peptide produced from a small gene inside the mitochondrial genome. It acts as a broad cytoprotective signal. Intracellularly it blocks apoptosis by binding the pro-death protein BAX, preventing mitochondrial-mediated cell death. Extracellularly it acts as a secreted signalling peptide via a trimeric receptor complex (CNTFR/WSX-1/gp130, driving STAT3 signalling) and via the formyl peptide receptor FPR2/FPRL1, and it modulates insulin/IGF-1 signalling (including interaction with IGFBP3). Net effect in models: protection against oxidative stress, apoptosis, hypoxia and metabolic injury.
What's it studied for?
Research contexts. Not proven uses, and not recommendations.
Does the human evidence stack up?
Human evidence is observational, not interventional. Cohort and cross-sectional studies report that higher levels of naturally circulating humanin are associated with longevity, with offspring of long-lived/centenarian families, and with better cognitive-age phenotypes, and that endogenous humanin tends to fall with age. These are correlations in people, not tests of humanin as a treatment. Crucially, there are no completed published randomised controlled trials of administered humanin (or analogues such as S14G-humanin) showing clinical benefit, and its pharmacokinetics, optimal route, immunogenicity and safety in humans are essentially uncharacterised. Almost all efficacy data come from cell culture and rodent (and some invertebrate) models.
What could go wrong?
- !No completed human interventional trials: efficacy as an administered drug in people is unproven.
- !Human pharmacology unknown: PK, bioavailability, route, half-life, immunogenicity and long-term safety of exogenous humanin/analogues have not been established.
- !Not a licensed medicine anywhere; products sold online are unlicensed 'research chemicals' labelled not for human consumption, with no quality, purity or sterility guarantees.
- !Pleiotropic signalling (STAT3, IGF/insulin axis, anti-apoptosis) cuts both ways: anti-apoptotic and growth-modulating effects raise theoretical concerns (e.g. around cancer cell survival) that are unresolved in humans.
- !Marketing hype: observational longevity correlations are routinely overstated as proof that injecting humanin extends human lifespan, which the data do not support.
Is it legal in the UK?
Not a licensed medicine in the UK: the MHRA has not authorised humanin or any humanin analogue for any indication, and there is no UK marketing authorisation. It is not an approved drug and is not available on prescription. Any humanin sold to UK consumers is an unlicensed substance, typically marketed as a 'research chemical' or 'not for human consumption' to sidestep the Human Medicines Regulations 2012; selling or supplying it for human medicinal use without authorisation would breach those regulations. The quality and identity of such grey-market material are unverified.
Sources
- 01A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer's disease genes and Abeta — Hashimoto Y, Niikura T, Tajima H, et al., PNAS (2001)
Landmark discovery paper identifying humanin as a 24-aa neuroprotective peptide.
- 02The mitochondrial derived peptide humanin is a regulator of lifespan and healthspan — Yen K, Mehta HH, Kim SJ, et al., Aging (Albany NY) (2020)
Humanin overexpression extends lifespan in C. elegans (daf-16 dependent) and a humanin analogue improves metabolic healthspan markers in middle-aged mice; circulating HN declines with age and correlates with longevity across species.
- 03Humanin Prevents Age-Related Cognitive Decline in Mice and is Associated with Improved Cognitive Age in Humans — Yen K, Wan J, Mehta HH, et al., Scientific Reports (2018)
Rodent intervention (HNG/S14G-humanin improves cognition in aged mice) plus human observational cognitive-age associations (SNP rs2854128).
- 04Humanin and Its Pathophysiological Roles in Aging: A Systematic Review — Coradduzza D, Congiargiu A, Chen Z, et al., Biology (MDPI) (2023)
Recent systematic review summarising the preclinical and observational evidence base.
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