pe
pep-10776 v1 CC-BY-SA-4.0

Humanin: natural cell-protection signal made by mitochondria

A small peptide produced inside your cells' energy factories that protects brain cells and may slow aging; experimental, not yet an approved drug.

statusbioassayed targetLONGEVITY length24 aa refs5
snapshot preclinical 0% confidence
Class
Mitochondrial-derived peptide (MDP)
Status
No approved therapeutic status in any jurisdiction
Best-supported effect
Cytoprotection and anti-apoptotic activity via BAX inhibition in cell and animal models; neuroprotection against amyloid-beta toxicity characterized in preclinical systems
Main caveat
No interventional human efficacy data for exogenous Humanin; observational human data reflect endogenous biomarker associations, not therapeutic causality
status 3 / 5 · 1 verified on platform
prediction metrics boltz-2 2.2.1
ipTM0.000
pTM0.408
avg pLDDT79.8
ranking score0.720
STRUCTURE · PEP-10776 × LONGEVITY
ranking0.720
?
RECEPTOR UNKNOWN
peptide conformation only · no target structure
target interface 4.5Å peptide drag rotate · ctrl+scroll zoom · right-click pan
sequence24 aa
1510152024
MAPRGFSCLLLL TSEIDLPVKRRA
in the news 9 articles
overview readme

Snapshot

Class: Mitochondrial-derived peptide (MDP)
Evidence tier: Animal-only evidence
Status: No approved therapeutic status in any jurisdiction
Best-supported effect: Cytoprotection and anti-apoptotic activity in cell and animal models; neuroprotection against amyloid-beta toxicity characterized in preclinical systems
Main caveat: No interventional human efficacy data for exogenous Humanin; observational human data reflect endogenous biomarker associations, not therapeutic causality


What this is

Humanin is a 24-amino-acid peptide encoded by a short open reading frame within the mitochondrial 16S rRNA gene. It was first described in 2001 through independent work identifying a neuroprotective factor in surviving neurons from Alzheimer's disease brain tissue. Humanin became the founding member of the mitochondrial-derived peptide (MDP) family, which later expanded to include MOTS-c and the SHLP peptides. Endogenous Humanin levels decline with age, and observational human data show correlations between circulating levels and metabolic and cognitive parameters — though causality has not been established.

The peptide has well-characterized cytoprotective biology in cell and animal systems: BAX inhibition, IGFBP-3 binding, and STAT3 activation are replicated mechanisms. What has not been established is any therapeutic effect of administering exogenous Humanin in humans. Most preclinical research uses the synthetic HNG (S14G-Humanin) analog, which is approximately 1000-fold more potent than wild-type Humanin in some neuroprotection models; results from HNG studies do not translate directly to wild-type Humanin at equivalent mass doses.


Evidence map

Evidence layerGradeWhat it supports
HumanObservational / biomarkerCirculating Humanin levels correlate with age, metabolic parameters, and cardiovascular markers; no interventional human efficacy data for exogenous Humanin identified in the available literature
AnimalModerate–strongNeuroprotection in Alzheimer's models, healthspan extension, cardioprotection in ischemia-reperfusion, and insulin sensitivity in rodent and other animal experiments
In vitroStrongBAX inhibition, IGFBP-3 binding, STAT3 activation, amyloid-beta toxicity reduction, retinal pigment epithelium protection — well-replicated in cell systems
ComputationalNot presentNo computational or structural prediction data identified
MechanismStrongMultiple independent pathways verified in cell and preclinical systems; mechanism plausibility is the strongest pillar of the Humanin evidence base

Most published RCTs in the reference set measured endogenous Humanin levels as a biomarker response to exercise, radiation, or other interventions — these are biomarker association studies, not exogenous Humanin therapy trials. A large share of the mechanistic and preclinical evidence originates from or has been advanced substantially by one research network (Pinchas Cohen's laboratory, USC); independent replication depth varies across individual claims.


Claim check

ClaimVerdictEvidence layerConfidence
Cytoprotection and anti-apoptotic activity via BAX inhibitionSupported (preclinical / in vitro)In vitro, animalHigh — extensively replicated in cell systems and animal models
Neuroprotection against amyloid-beta toxicitySupported (preclinical)In vitro, animalMedium — strong cell-model evidence; animal model replication present; no human interventional data
Improved insulin sensitivitySupported (preclinical)AnimalMedium — animal model evidence present; human interventional evidence absent
Cardioprotection in ischemia-reperfusionSupported (preclinical)AnimalMedium — animal model evidence; no human trial data attached
Observational association between endogenous Humanin levels and health outcomesSupported (observational)HumanMedium — causality not established; direction of association does not confirm that exogenous supplementation produces the same effect
Therapeutic efficacy of exogenous Humanin in humans for any indicationNot establishedHumanHigh confidence in the verdict — no completed Phase II or controlled human trial of exogenous Humanin identified in the available literature
Exogenous Humanin is equivalent to HNG (S14G-Humanin) at the same mass doseNot establishedAnimalHigh confidence in the verdict — HNG is approximately 1000-fold more potent than wild-type Humanin in some preclinical neuroprotection models; the two are not interchangeable
Humanin supplementation restores youthful function by reversing age-related declineNot establishedNoneHigh confidence in the verdict — age-associated decline in an endogenous biomarker does not imply that exogenous restoration produces equivalent effects; no interventional human data

Experimental exposure

This section reports exposure used in animal experiments and preclinical studies. It does not establish human dosing.

ContextSystemExperimental exposureDurationEndpointLimitation
Rodent neuroprotection studiesMice / rat modelsBroad range reported across studies (source describes 0.1–10 mg/kg in rodents, often using HNG analog)Days to weeks depending on endpointAmyloid-beta toxicity markers, survival, behavioral endpointsHNG analog used preferentially for potency reasons; results do not directly translate to wild-type Humanin; no human PK established
Healthspan / lifespan studiesRodent modelsLong-duration administration; exact regimen not individually extractedExtended (weeks to months)Healthspan and lifespan markersRodent duration does not translate to human protocol; no human replication
Insulin sensitivity experimentsRodent metabolic modelsStudy-specific dose; exact regimen not individually extractedStudy-specificInsulin sensitivity markers, AMPK activationNo human translation established

No human pharmacokinetic data for exogenous Humanin are available in the available literature. All dose-related information describes animal experimental contexts or forum-reported extrapolations. Forum-described community protocols (subcutaneous injection, research-chemical sourcing) are not included in this section because they represent community use patterns without clinical or experimental anchor — they are not studied exposure.


Preclinical safety signals

SignalSystemNotes
Generally well tolerated in animal and cell studiesRodent / cell systemsavailable literature reports no major toxicity signals in preclinical studies; duration and species limitations apply
Anti-apoptotic mechanism and theoretical cancer-cell survival concernTheoretical / mechanisticBAX inhibition that protects normal cells could theoretically support tumor cell survival; this concern has not been resolved by clinical data and is flagged explicitly in available literature
Theoretical interaction with pro-apoptotic cancer therapiesTheoretical / mechanisticConcurrent use with chemotherapy or radiation sensitizers that depend on inducing apoptosis in target cells could in principle oppose therapeutic intent; no clinical interaction data exist
Theoretical additive effect with insulin-sensitizing agentsTheoretical / mechanisticPreclinical insulin-sensitizing effects raise theoretical concern for additive effects with insulin, sulfonylureas, or GLP-1 agonists; not clinically characterized
Long-term safetyNot establishedNo chronic human safety data; no human pharmacovigilance data
Human reproductive and developmental safetyNot establishedNo reproductive toxicology data identified; no pediatric safety data

Research the following populations as having specific theoretical or preclinical concerns: active or recent-history cancer, pregnancy, breastfeeding, pediatric use, and concurrent use of pro-apoptotic therapies. These are reported as source-identified contraindications, not clinically validated exclusion criteria.


Regulatory status

Region / bodyStatusNotes
US (FDA)Not approvedNot approved for any indication; not a recognized dietary supplement ingredient; no established compounding pathway; sold through research-chemical suppliers not authorized for human use
EUNot approvedNot approved as a medicine in any EU jurisdiction identified in the available literature
UKNot approvedNot approved; availability through research-chemical channels subject to local rules
CanadaNot approvedNot approved in any jurisdiction identified in the available literature
Russia / otherNot approvedUnlike some peptides approved regionally (e.g., Cerebrolysin, Selank), Humanin has no clinical regulatory approval in any jurisdiction per the available literature
WADANot listed by name; likely prohibited under S0per available sources: Humanin is not named on the WADA Prohibited List; because it is not approved by any governmental health authority for human therapeutic use, Research it likely falls under WADA's S0 catch-all category prohibiting unapproved substances. Current list status not independently refreshed in this card.

Mechanism

Humanin exerts cytoprotective effects through several independently characterized pathways in cell and animal systems.

BAX inhibition: Humanin directly interacts with BAX to prevent mitochondrial membrane permeabilization, blocking a key step in the intrinsic apoptosis pathway. This mechanism is among the most replicated in the preclinical literature and is the basis for the anti-apoptotic characterization.

IGFBP-3 binding: Humanin binds insulin-like growth factor binding protein-3 (IGFBP-3), modulating IGF-1 signaling. This interaction places Humanin within the IGF-1 axis and raises mechanistic interactions with growth hormone and IGF-1-related therapies.

STAT3 activation: Humanin activates the STAT3 signaling pathway, which has downstream effects on cell survival, inflammation, and immune function. STAT3 involvement introduces a broad theoretical interaction surface with inflammatory and immune-modulating therapies.

AMPK activation / insulin sensitivity: In metabolic model systems, Humanin has been shown to improve insulin sensitivity through AMPK activation and reduce inflammatory cytokine production.

Amyloid-beta toxicity reduction: In neuronal cell systems, Humanin reduces toxicity associated with amyloid-beta peptide accumulation — the primary mechanistic rationale for neuroprotection research in Alzheimer's disease models.

All of these mechanisms are characterized in cell or animal systems. Target confidence for each pathway is verified (in vitro / preclinical); clinical translation in humans has not been established for any pathway.


Chemistry

FieldValue
Amino-acid chain24-amino acid sequence; exact one-letter sequence not individually extracted's source
Length24 amino acids
TopologyLinear
OriginEncoded by a short open reading frame within the mitochondrial 16S rRNA gene (16S rDNA)
Key analogHNG (S14G-Humanin): glycine substituted at position 14 for serine; approximately 1000-fold more potent than wild-type in some preclinical neuroprotection assays
Sequence confidenceNeeds review — source does not provide one-letter sequence; sequence should be verified against primary chemistry source before population
Molecular weightNot extracted from source
CAS / formulaNot extracted from source

Open questions

  • Human interventional evidence: No completed Phase II or controlled human trial of exogenous Humanin for any clinical endpoint has been identified. The distance between well-characterized endogenous biology and validated exogenous therapeutic use is currently unbridged.
  • Human pharmacokinetics: Absorption, distribution, clearance, and bioavailability of exogenous Humanin by subcutaneous or other routes are not established in humans. Without PK data, dose extrapolations from animal studies have no validated anchor.
  • Analog equivalence in humans: Most preclinical research uses HNG (S14G-Humanin) at doses exploiting its ~1000-fold potency advantage. Whether wild-type Humanin produces comparable effects at achievable exogenous doses in humans is unresolved. The research-chemical market conflates the two molecules in ways the evidence does not support.
  • Cancer-risk signal: The BAX-inhibiting anti-apoptotic mechanism raises a specific theoretical question about tumor-cell survival. This has not been resolved by human pharmacovigilance data, and the concern is explicitly flagged in available literature.
  • Causal direction of observational associations: Observational studies show Humanin levels correlate with age, metabolic, and cognitive parameters. Whether declining Humanin is a cause, consequence, or bystander marker of aging biology is not established. Supplementation logic based on correlation alone is premature.
  • Dose-response in humans: No dose-finding studies in humans have been completed. Forum protocols extrapolated from rodent studies are not a validated basis for human dosing.
  • Long-term safety: Chronic exposure data in humans are absent. No pharmacovigilance program has been established for exogenous Humanin use.
Hypotheses4 directions▾ collapse

Research directions for this peptide, selected from the current sources — hypotheses you can explore and model. None of it is proven yet; tap any one to see the full thinking.

openupdated 2026-06-05

Does the age-related drop in Humanin come before, and actually cause, the neuron death seen in Alzheimer's disease?

If Humanin loss is the first domino, replenishing it early in aging could prevent the chain of events that leads to dementia, giving millions of people a way to protect their brain health before symptoms appear.

The hypothesis
The age-related decline in circulating Humanin levels drives a shift in the BAX/BCL-2 rheostat in neurons toward apoptosis, and this shift is causally upstream of amyloid-beta neurotoxicity rather than a parallel or downstream consequence of it.
Why it’s plausible
Humanin was originally identified in surviving neurons from Alzheimer's disease tissue and characterized as neuroprotective against amyloid-beta toxicity. If Humanin decline with age precedes amyloid-beta accumulation in vulnerable neurons, then low Humanin could be a permissive condition that lowers the apoptotic threshold, making neurons susceptible to amyloid-beta rather than amyloid-beta independently killing otherwise robust neurons. This causal ordering has not been tested longitudinally.
Why it matters
If Humanin depletion is upstream of amyloid-beta toxicity, restoring Humanin levels could be protective even before amyloid burden rises, opening a preventive rather than purely therapeutic window in Alzheimer's disease.
Plausibility.60
Novelty.55
Impact.75
Basis · grounding1 paper · 2 computed/notes
[1]
noteHumanin was first identified in surviving neurons from Alzheimer's disease brain; neuroprotection against amyloid-beta toxicity is characterized in preclinical systems; endogenous levels decline with age.
[2]
paper
Anti-apoptotic effects via BAX binding are documented; age-associated decline in Humanin is noted.
doi: 10.52793/jscr.2025.6(2)-78
[3]
noteObservational human data show correlations between circulating levels and cognitive parameters, but causality is unestablished.
openupdated 2026-06-05

Does the sulfur-containing amino acid in Humanin cause it to lose its protective power when the cell environment is most damaged?

If true, a simple chemical tweak removing that vulnerable amino acid could produce a version of Humanin that stays active during heart attacks or strokes, potentially saving more tissue and benefiting patients in intensive care or surgery.

The hypothesis
The Cys residue at position 8 of Humanin (MAPRGFSCLLLL...) forms a functionally significant disulfide or redox-sensitive thiol that regulates its cytoprotective potency in oxidizing environments such as the mitochondrial intermembrane space, meaning Humanin acts as a redox sensor whose activity is dampened under oxidative stress exactly when it is most needed.
Why it’s plausible
Position 8 in the 24 aa sequence is a cysteine (C), the only such residue. The mitochondrial intermembrane space and extracellular milieu during ischemia/reperfusion are highly oxidizing. A free thiol at this position could form an intramolecular or intermolecular disulfide under oxidative conditions, altering the LLLL hydrophobic core conformation. If disulfide formation reduces BAX-binding affinity, Humanin would paradoxically lose potency when oxidative stress peaks, a vulnerability relevant to cardiac and ischemic disease settings.
Why it matters
If confirmed, this would explain why exogenous wild-type Humanin underperforms expectations in oxidative disease models, and would justify engineering a Cys-to-Ser or Cys-to-Ala substitution to produce a redox-insensitive variant with sustained activity under oxidative stress.
Plausibility.55
Novelty.65
Impact.60
Basis · grounding1 paper · 2 computed/notes
[1]
sequenceMAPRGFSCLLLLTSEIDLPVKRRA: single Cys at position 8, flanked by hydrophobic LLLL stretch; no other Cys in the 24 aa sequence.
[2]
paper
Glutathione and mitochondria literature cited in context of redox biology; mitochondrial redox environment is relevant to peptide thiol status.
doi: 10.1007/s10495-025-02165-2
[3]
noteHNG (S14G) analog is ~1000-fold more potent than wild-type in some neuroprotection models; the potency gap between wild-type and analog suggests wild-type has an intrinsic liability not present in HNG.
openupdated 2026-06-05

Does Humanin only protect cells that have stopped dividing, making it safer to use without accidentally helping tumors grow?

If Humanin spares cancer cells from protection, it could be used to shield healthy organs during chemotherapy or after a heart attack without the risk of promoting tumor survival, a major concern with any anti-cell-death drug.

The hypothesis
Humanin selectively protects post-mitotic, non-dividing cells (neurons, cardiomyocytes) over proliferating cells because STAT3 activation in proliferating cells drives a competing pro-survival program that renders BAX-mediated apoptosis redundant, making Humanin's BAX-inhibitory effect cell-cycle-state-dependent.
Why it’s plausible
STAT3 is a replicated activation target of Humanin. In proliferating cells, STAT3 is constitutively active and drives BCL-XL and MCL-1 expression, already suppressing BAX. In post-mitotic cells, these pathways are attenuated and BAX-dependent apoptosis is the dominant death pathway. If Humanin's cytoprotective efficacy depends on BAX being the rate-limiting apoptotic trigger, its benefit would concentrate in post-mitotic tissues where BAX is not already redundantly blocked by STAT3-driven BCL-2 family members.
Why it matters
This would explain why Humanin's best evidence is in neurons and cardiomyocytes and suggest that it would have minimal undesired pro-survival effects in rapidly dividing cancer cells, a key safety consideration for any systemic therapeutic use.
Plausibility.50
Novelty.55
Impact.65
Basis · grounding2 papers · 1 computed/note
[1]
noteBAX inhibition, IGFBP-3 binding, and STAT3 activation are replicated mechanisms; best-supported cytoprotective effects are in neuronal and cardiac preclinical models.
[2]
paper
Anti-apoptotic effects via BAX binding documented; STAT3 activation cited as a Humanin mechanism.
doi: 10.52793/jscr.2025.6(2)-78
[3]
paper
Cardiac and metabolic effects of related signaling pathways in aged animals are relevant context for post-mitotic cell specificity.
doi: 10.3389/fcvm.2026.1751243
openupdated 2026-06-05

Does the extra segment on the cytosolic form of Humanin make it better at blocking the protein that triggers cell death?

If true, doctors and researchers could target the more potent form specifically, potentially reducing cell loss in conditions like Alzheimer's disease or heart attack with fewer side effects. This could help patients whose cells are dying prematurely due to stress or disease.

The hypothesis
Humanin's annotated 'longevity' target obscures a more precise mechanistic anchor: its primary cytoprotective action is direct BAX sequestration rather than canonical receptor-mediated longevity signaling, and the structural basis of this interaction differs between the 21 aa mitochondrial and 24 aa cytosolic isoforms.
Why it’s plausible
The 24 aa cytosolic form of Humanin (MAPRGFSCLLLLTSEIDLPVKRRA) contains a hydrophobic stretch (LLLL, positions 9-12) that is absent in truncated mitochondrial isoforms. BAX engagement requires hydrophobic groove contacts. If the extra three N-terminal residues in the cytosolic form alter helix amphipathicity, they could shift BAX-binding affinity and selectivity compared to the 21 aa form, explaining differential cytoprotective potency across compartments without invoking a longevity receptor at all.
Why it matters
Clarifying which isoform drives BAX inhibition would reframe Humanin not as a diffuse 'longevity signal' but as a compartment-specific apoptosis brake, enabling isoform-selective therapeutic design with reduced off-target receptor engagement.
Plausibility.55
Novelty.45
Impact.60
Basis · grounding1 paper · 2 computed/notes
[1]
paper
Both the 21 aa mitochondrial and 24 aa cytosolic forms are biologically active; anti-apoptotic effects via BAX binding are documented.
doi: 10.52793/jscr.2025.6(2)-78
[2]
sequenceMAPRGFSCLLLLTSEIDLPVKRRA: LLLL motif at positions 9-12 is a candidate hydrophobic BAX-groove contact surface, present in the 24 aa but not the 21 aa isoform.
[3]
noteBAX inhibition, IGFBP-3 binding, and STAT3 activation are replicated mechanisms; 'longevity' is an annotation, not a defined receptor.
details expand to inspect
full evidence table1 metrics
metricvaluetool
ranking score 0.71978759765625 boltz-2
3-letter notation
Met-Ala-Pro-Arg-Gly-Phe-Ser-Cys-Leu-Leu-Leu-Leu-Thr-Ser-Glu-Ile-Asp-Leu-Pro-Val-Lys-Arg-Arg-Ala
recipeboltz-2 2.2.1
parametervalue
modelboltz-2 2.2.1
weights
hardwarevast_v100_32gb
mlx version
python
random seed1
msa strategynone_monomer
runtime
predicted by
predicted at2026-05-23
citationbibtex
peptidemodel (2026). Humanin: natural cell-protection signal made by mitochondria (pep-10776, v1). PeptideModel. https://peptidemodel.com/card/pep-10776
@peptide{pep10776,
  sequence = {MAPRGFSCLLLLTSEIDLPVKRRA},
  target   = {longevity},
  author   = {peptidemodel},
  year     = {2026},
  status   = {bioassayed}
}
clinical trials 6 on ct.gov · checked 2026-05-09
ct.gov trials 6
PubMed RCT 2
by phase
6no phase
by status
1completed2recruiting3unknown
references 5 papers
discussion no comments
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