reviewed april 2026|next review october 2026|88 physicians psi has verified|255 published studies
Humanin
Humanin is a 24-amino-acid cytoprotective peptide encoded by the mitochondrial 16S rRNA gene, discovered in neurons that survived Alzheimer's disease pathology, with circulating levels declining approximately 40% between ages 20 and 80.
Evidence landscape: 255 published studies
255 published items. 17 human studies and 137 animal studies.
- 17 Human
- 137 Animal
- 46 Reviews
- 55 Other research
Not FDA-approved. Humanin is a naturally occurring (the body's own) mitochondrial-derived peptide available as a research compound. It is not available through standard pharmacies or through specialty pharmacies where a licensed pharmacist prepares a medicine from ingredients for an individual patient.
255 published studies including 17 human studies and 137 animal studies. Human data documents the age-related decline in circulating levels and correlations with metabolic and cognitive health. Controlled interventional trials are in early stages.
Provides cytoprotection through at least three independent pathways: STAT3 receptor signaling, IGFBP-3 binding, and direct Bax interaction. The S14G analog (HNG) is approximately 1,000-fold more potent in cell culture models.
PSI Assessment
Discovered in 2001 in brain cells that survived Alzheimer's disease pathology while surrounding neurons died, humanin is a 24-amino-acid mitochondrial-derived peptide that provides cytoprotection through at least three independent molecular pathways. Circulating levels decline approximately 40% between ages 20 and 80 in human cohorts. The animal data is consistent across multiple Alzheimer's, metabolic, and cardiovascular models. The S14G analog (HNG) shows 1,000-fold greater potency. The defining limitation is that controlled interventional trials giving exogenous humanin to humans are absent, and the translation from the body's own biology to administered therapy is not established.
Discovered in neurons that survived Alzheimer's pathology. Multi-layered cytoprotection through three independent pathways. Circulating levels decline 40% across the human lifespan.
The mechanism operates through three independent cytoprotective pathways. First, humanin binds the CNTFR (ciliary neurotrophic factor receptor)/WSX-1/gp130 trimeric receptor complex, activating STAT3 signaling and driving anti-apoptotic gene expression. Second, it binds IGFBP-3 directly, blocking a pro-apoptotic interaction that would otherwise trigger cell death through Bax at the mitochondrial membrane. Third, it binds Bax itself, preventing mitochondrial outer membrane permeabilization and cytochrome c release. The S14G humanin analog (HNG) achieves approximately 1,000-fold greater potency than native humanin in neuroprotection assays, making it the primary candidate for therapeutic development.
What the evidence supports
Humanin provides cytoprotection through at least three independent pathways: STAT3 receptor signaling, IGFBP-3 binding, and direct Bax interaction. Circulating levels decline approximately 40% between ages 20 and 80 in human cohorts. The S14G analog (HNG) is approximately 1,000-fold more potent in cell culture models. Neuroprotective effects are consistently demonstrated across multiple Alzheimer's and neurodegenerative disease animal models.
What is not yet established
Whether exogenous humanin administration produces clinically meaningful neuroprotection in humans with Alzheimer's or other neurodegenerative conditions. Controlled interventional trials are absent. Whether the age-related decline is a cause or consequence of aging. Optimal analog selection (native vs HNG) for therapeutic development.
Research Evidence
The findings below cover what independent research groups have established and where the evidence thins for therapeutic application.
Evidence by condition
Evidence dimensions across humanin research areas. Neuroprotection has the deepest animal data and most compelling discovery context. Metabolic health and aging have consistent correlation data. Cardiovascular and cancer research are at earlier stages.
| Condition | Mechanism | Animal evidence | Human evidence | Replication |
|---|---|---|---|---|
| Neuroprotection | ||||
| Metabolic Health | ||||
| Cardiovascular | ||||
| Aging | ||||
| Cancer Research |
Humanin was discovered in 2001 in a functional screen for survival factors in neurons that resisted Alzheimer's disease-related cell death (Hashimoto et al.). The discovery context is part of what makes humanin one of the more compelling peptides in neuroprotection research.
The discovery context is unusually compelling: the peptide was identified because researchers asked why some brain cells survived when surrounding neurons died from Alzheimer's pathology. This does not establish that humanin treats Alzheimer's disease, but it establishes a biologically meaningful role in neuronal survival.
Cytoprotection operates through at least three independent molecular pathways: STAT3 receptor signaling, IGFBP-3 binding, and direct Bax interaction. The multi-layered mechanism suggests robust protection rather than reliance on a single pathway.
Three independent pathways converging on cell survival is unusual for a single small peptide. This makes the cytoprotective signal more robust and may explain why humanin protects against diverse insults (amyloid-beta toxicity, metabolic stress, oxidative damage).
Circulating humanin levels decline approximately 40% between ages 20 and 80 in human cohorts, documented by multiple independent research groups. This decline parallels declines in other mitochondrial-derived peptides (MOTS-c) and correlates with metabolic and cognitive health markers.
The age-related decline is documented across independent groups. Whether this decline drives age-related disease or merely accompanies it is an open question. Correlation does not establish causation.
17 Human|137 Animal|46 Reviews
View all 255 indexed studiesHow Humanin Works
Humanin is a 24-amino-acid peptide, which means it is a short chain of building blocks that normally make up proteins. It is encoded by the mitochondrial genome - the DNA inside the energy-producing structures in cells - and functions as a stress-response signal that protects cells from programmed death.
Humanin works as a cellular protection signal produced by your mitochondria. When cells are under stress, humanin activates survival pathways that prevent those cells from self-destructing. It was found in brain cells that had survived Alzheimer's damage, suggesting it plays a role in helping cells resist conditions that would otherwise destroy them. Your body produces less of it as you age, which may leave cells more vulnerable to stress-related damage over time.
For a more detailed view of the biology, here is what researchers have observed at the molecular level.
Humanin is encoded within the 16S rRNA gene (MT-RNR2) of the mitochondrial genome, making it part of the mitochondrial-derived peptide (MDP) family alongside MOTS-c and SHLP1-6. Its cytoprotective mechanism operates at three levels: receptor-mediated STAT3 activation (through the CNTFR/WSX-1/gp130 trimeric complex) drives anti-apoptotic gene expression (Bcl-2, Mcl-1); direct binding to IGFBP-3 prevents the IGFBP-3/Bax pro-apoptotic axis; and direct Bax binding prevents mitochondrial outer membrane permeabilization and cytochrome c release. The S14G humanin analog (HNG) shows 1,000-fold greater potency in neuroprotection assays. Circulating levels are measurable in human plasma and decline approximately 40% between ages 20 and 80.
What is Humanin being studied for?
Researchers are studying Humanin across several health conditions. Each condition below is labeled with the strength of evidence that exists for that specific use, not for Humanin overall. This means a compound can have human studies for one condition but only animal data for another.
Neuroprotection
·Human TrialsHumanin was discovered in neurons surviving Alzheimer's pathology and consistently protects against amyloid-beta toxicity in cell and animal models. Human correlation studies link humanin levels to cognitive outcomes.
Limitations: All neuroprotection data is from cell culture, animal models, or human correlation studies. No controlled human trial has tested whether exogenous humanin prevents or slows neurodegeneration.
Metabolic Health
·Animal StudiesAnimal studies show humanin improves insulin sensitivity and glucose metabolism. The mechanism involves both central (hypothalamic) and peripheral (hepatic, adipose) metabolic signaling.
Limitations: All metabolic intervention data is from animal models. Human data is correlational only.
Cardiovascular
·Animal StudiesAnimal studies suggest humanin protects against cardiac ischemia-reperfusion injury and atherosclerosis progression through its cytoprotective mechanism.
Limitations: All cardiovascular data is from animal models. No human cardiovascular intervention studies exist.
Aging
·Animal StudiesCirculating humanin levels decline approximately 40% between ages 20 and 80 in humans. This decline correlates with increased vulnerability to age-related diseases.
Limitations: The observation that humanin declines with age does not establish that restoring levels will reverse aging processes. No interventional aging study has been conducted.
Cancer Research
·PreclinicalVery early research suggests humanin's anti-apoptotic properties may have complex interactions with cancer biology, but the evidence is minimal.
Limitations: Extremely limited data. The anti-apoptotic mechanism is a theoretical double-edged sword in cancer contexts.
Safety and Regulatory Status
FDA Status: Not FDA-approved for any indication. Humanin is a naturally occurring (the body's own) mitochondrial-derived peptide. No regulatory agency has evaluated humanin for therapeutic use.
Availability: Available as a research compound from peptide suppliers. Not available through standard pharmacies or specialty pharmacies where a licensed pharmacist prepares a medicine from ingredients for an individual patient.
Class context: Humanin is part of the mitochondrial-derived peptide (MDP) family alongside MOTS-c. Circulating levels decline with age. The anti-apoptotic mechanism raises a theoretical concern in cancer biology: protecting cells from programmed death could theoretically protect cancerous cells.
As a naturally occurring (the body's own) peptide, humanin has a baseline safety context. Animal studies at therapeutic and supratherapeutic doses have not reported significant adverse effects. Human safety data from interventional studies is very limited. The anti-apoptotic mechanism is a theoretical concern in cancer biology.
Peptide Structure
Technical molecular data for researchers and clinicians.
Questions and Comparisons
Questions the evidence raises for a Humanin discussion.
Comparison and Related Research
Humanin is most often compared with other mitochondrial-targeting peptides. The comparisons below outline how each differs.
Head-to-head comparisons
Full research comparisons covering Humanin and another peptide side by side.
Humanin vs MOTS-c
Both encoded by mitochondrial DNA. MOTS-c targets metabolism. Humanin targets cell survival. Evidence-graded comparison of mitochondrial-derived peptides.
View full comparisonRelated compounds
Frequently Asked Questions
References
Each citation links to the original study on PubMed, the U.S. National Library of Medicine database.
- 1.The landmark paper characterizing humanin as a neuroprotective factor originally identified in surviving neurons from Alzheimer's disease patients. Demonstrated that humanin protects against multiple Alzheimer's-related insults including amyloid-beta toxicity, presenilin mutations, and APP-induced cell death in neuronal cell cultures.Hashimoto Y et al., 2001 in J Neurosci. View on PubMed
- 2.Demonstrated that humanin acts as a central regulator of insulin sensitivity through hypothalamic signaling. When administered intracerebroventricularly in mouse models, humanin improved peripheral insulin action and glucose metabolism, revealing a previously unknown brain-to-body metabolic signaling pathway for this mitochondrial-derived peptide.Muzumdar RH et al., 2009 in PLoS One. View on PubMed
- 3.Examined the relationship between circulating humanin levels and aging outcomes across multiple species. Found that humanin levels decline with age in humans and that higher levels are associated with better metabolic health. In animal models, humanin supplementation improved healthspan markers and extended lifespan in C. elegans.Yen K et al., 2020 in Aging (Albany NY). View on PubMed
- 4.Identified a direct physical interaction between humanin and IGFBP-3, revealing a mechanism through which humanin blocks IGFBP-3-induced apoptosis. This interaction proved critical for understanding how humanin exerts its pro-survival effects, linking it to the IGF signaling system and expanding the known scope of its biological activity.Ikonen M et al., 2003 in Proc Natl Acad Sci U S A. View on PubMed
Medical Disclaimer
This content is for educational and informational purposes only and does not constitute medical advice. The information presented reflects published research as indexed by PSI and should not be used to make treatment decisions. Always consult a qualified healthcare provider before starting, stopping, or modifying any treatment.