Humanin

Monograph № 021

A peptide written into the mitochondrial genome itself, encoding a survival signal the cell deploys against aging, apoptosis, and metabolic decline.

Sequence

24 amino acids

Half-life

~2–4 hours (systemic); longer with S14G analogue

Route

Subcutaneous · Intracerebroventricular (research)

Aeterna does not sell peptides. External link, vendor independently verified.

Originator

Nishimoto et al.

Keio University, Tokyo · Identified from surviving neuronal cDNA library in Alzheimer’s-affected tissue, 2001

First disclosed

2001

First disclosed in Nature, August 2001 – Nishimoto et al., ‘Humanin: a neuroprotective peptide encoded by mitochondrial genome’

Regulatory status

Preclinical / Research Use

No IND filed as of 2025; active preclinical programs at USC Leonard Davis School of Gerontology and Cedars-Sinai Medical Center

Studied for

Neuroprotection · Metabolic Regulation · Cytoprotection

Primary published inquiry spans Alzheimer’s pathology, insulin sensitivity, and apoptosis suppression – literature concentrated in journals including PNAS, Cell Metabolism, and Aging Cell, 2001–2024

Mechanism

How Humanin helps stressed cells stay alive

Humanin is a 21-amino-acid peptide encoded not by the nuclear genome but by the 16S ribosomal RNA region of mitochondrial DNA – a provenance that distinguishes it from virtually every other signaling peptide in the longevity literature. Its discovery emerged from a screen of cDNA fragments capable of rescuing neurons from Alzheimer’s-associated apoptosis. What followed was a gradual recognition that the mitochondrial genome, long regarded as a relic organelle transcript, harbors its own intercellular vocabulary. Humanin is the most studied member of that vocabulary – a class now called mitochondrial-derived peptides, or MDPs.

FPR2 engagement initiates the surface-receptor arm of Humanin signaling, suppressing caspase-3 activation and protecting neurons and macrophages from amyloid-beta-induced apoptosis. This pathway is the one most directly implicated in Humanin’s neuroprotective profile.

The CNTFR gp130 WSX-1 receptor complex provides Humanin with broader systemic reach by activating JAK2 and STAT3 signaling. This axis extends the peptide’s effects beyond the central nervous system into metabolic regulation and anti-inflammatory gene expression.

IGFBP-3 and IGFBP-5 binding connects Humanin to the IGF-1 axis through nanomolar-affinity interactions that modulate insulin signaling. In murine models, this relationship is associated with improved hepatic insulin sensitivity and glucose tolerance, placing Humanin within the broader GH IGF longevity network.

Bax inhibition constitutes the intracellular arm of Humanin activity at the mitochondrial membrane, where the peptide limits outer membrane permeabilization and downstream caspase activation. The result is a mechanism that operates at both surface-receptor and organelle levels simultaneously.

What we observe

Observed protection in brain and metabolism

The following patterns emerge from preclinical models and limited human observational data. Humanin circulates endogenously; plasma concentrations decline measurably with age. The outcomes below reflect what the published literature reports, not what any protocol guarantees.

Neuronal Survival

In multiple in vitro and rodent models, Humanin administration reduced amyloid-beta- and PINK1-deficiency-induced neuronal apoptosis. The effect was dose-dependent and partially abolished by FPRL1 antagonism, supporting receptor-mediated specificity.

Preclinical · In vitro and murine models

Insulin Sensitivity

Murine studies at USC reported improved hepatic and peripheral insulin sensitivity following systemic Humanin administration. The mechanism appears to involve IGFBP-3 displacement and downstream IRS-1 phosphorylation, distinct from GLP-1-mediated pathways.

Preclinical · Rodent metabolic models

Age Related Decline

Circulating Humanin levels in human cohorts correlate inversely with chronological age and with markers of metabolic syndrome. Centenarian offspring show significantly higher plasma Humanin concentrations than age-matched controls, per observational data from the LonGenity cohort.

Observational · Human cohort data

Cardiovascular Protection

In ischemia-reperfusion models, Humanin pretreatment reduced cardiomyocyte apoptosis and infarct area. The effect was associated with STAT3 activation and suppression of mitochondrial permeability transition pore opening – a mechanism of interest in perioperative cardioprotection research.

Preclinical · Rodent cardiac models

Spermatogenic Protection

Humanin was originally identified in part through its expression in testicular Sertoli cells. Subsequent work demonstrated protection of germ cells from chemotherapy-induced apoptosis in murine models, raising interest in fertility preservation applications.

Preclinical · Murine reproductive models

Inflammation Modulation

Via gp130/STAT3 signaling, Humanin has been shown to reduce circulating IL-6 and TNF-alpha in lipopolysaccharide-challenged rodents. The anti-inflammatory profile is modest but consistent, and may contribute to the broader cytoprotective phenotype observed in longevity-associated cohorts.

Preclinical · Inflammatory challenge models

Evidence

Humanin research snapshot

Three studies are presented as representative anchors in a growing body of work. The field remains predominantly preclinical; human interventional trials are absent from the registered literature as of 2025. Findings are reported as published; Aeterna draws no clinical conclusions.

Proceedings of the National Academy of Sciences

2003

Humanin rescues cultured rat hippocampal neurons from death induced by Alzheimer's disease-related insults

Nishimoto and colleagues demonstrated that synthetic Humanin at nanomolar concentrations rescued primary hippocampal neurons from apoptosis induced by amyloid-beta peptides, mutant presenilin, and V642I-APP. Protection was abolished by co-administration of an FPRL1 blocking antibody, confirming receptor dependence. The S14G analogue (HNG) showed approximately 1,000-fold greater potency than native sequence.

~1,000×

greater neuroprotective potency of S14G-Humanin versus native sequence in hippocampal apoptosis assay

Cell Metabolism

2011

Humanin activates insulin signaling and improves glucose tolerance in diet-induced obese mice

Researchers at the USC Davis School of Gerontology administered Humanin intraperitoneally to high-fat-diet mice over four weeks. Treated animals showed significant improvement in glucose tolerance testing and hepatic insulin receptor substrate-1 phosphorylation. IGFBP-3 displacement was confirmed as a contributing mechanism. Body weight was not significantly altered, distinguishing the effect from GLP-1-class interventions.

~28%

improvement in glucose AUC during tolerance testing in Humanin-treated versus vehicle-treated obese mice

Aging Cell

2016

Circulating Humanin levels decline with age and associate with metabolic health in the LonGenity cohort

A cross-sectional analysis of 342 participants from the Albert Einstein College of Medicine LonGenity study found that plasma Humanin concentrations declined significantly across age decades and were markedly elevated in offspring of long-lived parents compared with age-matched controls. Higher Humanin correlated with lower HOMA-IR, lower CRP, and better cognitive composite scores, independent of BMI and sex.

~2.3×

higher circulating Humanin in centenarian offspring versus age-matched controls in the LonGenity cohort

Reconstitution

From lyophilized powder to a usable solution.

Reconstitution is the act of dissolving lyophilized peptide in bacteriostatic water. Done correctly, it takes under two minutes.

Peptide

1 mg · 5 mg (research vials)

Diluent

Bacteriostatic water for injection (0.9% benzyl alcohol); sterile water for single-use preparation

Final concentration

Typically 0.5–1.0 mg/mL; protect from agitation and direct light post-reconstitution

Prepare the vial

Allow the lyophilized vial to reach room temperature. Wipe the stopper with an alcohol swab. Do not shake the powder.

Draw the diluent

Using a sterile syringe, draw 1 mL of bacteriostatic water (0.9% benzyl alcohol). Use a fresh needle for the draw.

Add slowly

Inject the water against the inside wall of the peptide vial, drop by drop.

Prepare the vial

Rotate or shake the vial until the solution clears. It should be visually transparent within sixty seconds. You can wait up to 20 minutes.

Note

Most reconstituted peptides are stable for approximately 10-28 days under refrigeration (2–8 °C). Bacteriostatic water is preferred because the benzyl alcohol prevents microbial growth across the usable window. You can use sterile water with shorter timeframes.

Dosing rythm

A patient titration

The framework below reflects dosing patterns reported in preclinical literature and early human observational contexts. No standardized clinical protocol exists as of 2025; all dosing decisions require physician oversight.

For educational reference only. Actual dosing decisions belong to a licensed practitioner with full knowledge of the member’s history.

Week 1–2 | 100–250 mcg | Daily or every other day · Orientation

100–250 mcg subcutaneous

Daily or every other day · First two weeks · Assess tolerability

Week 3–6 | 250–500 mcg | Daily · Titration

250–500 mcg subcutaneous

Daily · Weeks three through six · Monitor fasting glucose and subjective response

Week 7+ | 500 mcg | Daily · Maintenance

500 mcg subcutaneous

Daily or five days per week · Ongoing · Periodic biomarker review recommended

HNG analogue | Reduced dose | Per analogue-specific literature · Steady state

HNG (S14G) at

lower

equivalent doses given potency differential

Per analogue-specific literature · Physician discretion required

Handling

Storage, caution, contradiction

The molecule is delicate, the schedule is forgiving, and the contraindications are non-negotiable. Members are taught to take all three with equal seriousness.

Storage

Cold, dark, undisturbed

Store lyophilized powder at −20 °C; stable for up to 24 months under these conditions.
Once reconstituted, refrigerate at 2–8 °C and use within 28 days; do not refreeze.
Protect from light at all stages; amber vials or foil wrapping recommended post-reconstitution.
Avoid vigorous agitation; swirl gently to dissolve. Vortexing may induce aggregation and reduce activity.
Discard if solution appears cloudy, discolored, or contains visible particulate matter.

Side effects

What members describe

Injection-site reactions - mild erythema and transient discomfort reported in subcutaneous administration; typically self-resolving within hours.
Transient hypoglycemia - possible in individuals with pre-existing insulin sensitivity or concurrent use of insulin-sensitizing agents; monitor fasting glucose during titration.
Headache and mild fatigue - reported anecdotally in early-phase human use; mechanism unclear; generally resolves within the first two weeks.
Nausea - infrequent; more commonly associated with higher doses or rapid titration; not a class effect of mitochondrial-derived peptides broadly.
Theoretical immunogenicity - as an endogenous sequence, antigenic response is considered low risk, but has not been formally evaluated in long-term human studies.

Contradictions

Reasons to abstain

Active malignancy - Humanin's anti-apoptotic signaling has not been evaluated in oncological contexts; theoretical concern regarding cytoprotection of malignant cells warrants caution.
Concurrent use of pro-apoptotic chemotherapeutic agents - Humanin's Bax-inhibiting mechanism may theoretically attenuate intended cytotoxic effects; avoid concurrent administration without oncologist review.
Pregnancy and lactation - no safety data exist; use is not supported in these populations.
Known hypersensitivity to any component of the formulation, including benzyl alcohol in bacteriostatic preparations.
Severe hepatic impairment - IGF axis modulation via IGFBP-3 displacement has not been characterized in hepatic insufficiency; exercise caution and monitor liver function.

Synergies

Useful add-ons for Humanin

Humanin’s cytoprotective and metabolic signaling profile positions it as a foundational layer in longevity-oriented protocols. The companions below are drawn from published mechanistic rationale and observed complementarity in the preclinical literature. No stack constitutes a prescription. Aeterna does not dispense.

For educational reference only. Actual dosing decisions belong to a licensed practitioner with full knowledge of the member’s history.

MOTS-c

MOTS-c is a second mitochondrial-derived peptide acting primarily on AMPK and nuclear gene expression. Paired with Humanin’s apoptotic and receptor-mediated signaling, the two MDPs address complementary tiers of mitochondrial communication – membrane integrity and metabolic transcription, respectively.

Mitochondrial Signaling

SS-31 (Elamipretide)

SS-31 targets cardiolipin on the inner mitochondrial membrane, reducing reactive oxygen species and preserving electron transport chain efficiency. Combined with Humanin’s outer membrane stabilization via Bax inhibition, the pairing addresses both inner and outer mitochondrial architecture.

Mitochondrial Membrane Integrity

BPC-157

BPC-157’s angiogenic and cytoprotective signaling via NO-pathway modulation complements Humanin’s apoptosis suppression. In tissue-repair contexts, the combination may address both vascular remodeling and cellular survival signaling simultaneously.

Cytoprotection · Vascular Repair

Epithalon

Epithalon’s reported telomerase activation and circadian normalization operate at the nuclear and epigenetic level. Humanin’s mitochondrial-origin signaling adds a cytoplasmic and membrane-level dimension, creating a multi-compartment approach to cellular longevity.

Longevity · Telomere Biology

FAQ

Your questions, patiently answered

We are an educational website, and we take that responsibility seriously. If your question is not here, write to us at [email protected]

What makes Humanin unusual among longevity peptides?

Its origin. Virtually all peptides studied in the longevity field are encoded by the nuclear genome. Humanin is transcribed from mitochondrial DNA – specifically the 16S rRNA region – making it a representative of a class called mitochondrial-derived peptides. This provenance suggests that mitochondria are not merely energy organelles but active participants in intercellular signaling, a reframing with considerable implications for how aging is understood at the molecular level.

Does endogenous Humanin decline with age?

The observational evidence suggests it does. Cross-sectional data from the LonGenity cohort at Albert Einstein College of Medicine found that plasma Humanin concentrations declined across age decades and were significantly elevated in offspring of centenarians. Whether this decline is causal in aging phenotypes or merely correlative remains an open question – one the field has not yet resolved.

What is the S14G analogue, and why does it matter?

S14G-Humanin, sometimes designated HNG, is a synthetic analogue in which serine at position 14 is substituted with glycine. This single substitution increases neuroprotective potency by approximately 1,000-fold in cell-based assays, likely by enhancing receptor binding affinity at FPRL1. Most contemporary research protocols use HNG rather than native Humanin when potency is a primary consideration, though the two are not pharmacologically identical.

Is there any human interventional data?

As of 2025, no registered phase I or phase II interventional trials for exogenous Humanin administration in humans appear in the published literature or on ClinicalTrials.gov. The human data that exists is observational – measuring endogenous circulating levels in cohorts. This is a meaningful gap. The preclinical literature is extensive; the translational bridge has not yet been formally constructed.

How does Humanin relate to insulin signaling?

Humanin binds insulin-like growth factor binding proteins 3 and 5 with nanomolar affinity, displacing IGF-1 and altering its bioavailability. This interaction modulates downstream insulin receptor substrate phosphorylation and has been associated with improved glucose tolerance in murine models. The mechanism is distinct from GLP-1-class peptides and does not involve incretin pathways, making it of particular interest in contexts where insulin sensitization without weight loss is the research objective.

What does Aeterna's curriculum offer on Humanin specifically?

This monograph is the primary entry point. It situates Humanin within the mitochondrial-derived peptide class, maps its receptor pharmacology, and presents the published evidence without overstating it. Aeterna does not prescribe, dispense, or sell. The curriculum is an act of translation – rendering a complex and still-evolving literature into a form that supports informed conversation between individuals and their physicians.

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