Humanin
Humanin is a small mitochondria-derived peptide encoded within the 16S rRNA region of the mitochondrial genome. It is a cytoprotective peptide that protects cells from apoptosis, reduces neurodegeneration, improves insulin sensitivity, and declines with age — making it a focus of longevity and anti-aging research.
Common Dosage
2mg - 8mg subcutaneous weekly (research dosing)
Category
Longevity
- Neuroprotection and Alzheimer's research
- Cytoprotection (anti-apoptotic)
- Improved insulin sensitivity
- Mitochondrial function support
- Age-related cognitive decline research
- Cardiprotective effects
Humanin was discovered in 2001 by Nishimoto and colleagues at Tokyo Metropolitan Institute of Gerontology while screening a cDNA library derived from the brains of Alzheimer's disease patients for proteins that could rescue neurons from Alzheimer's-related cell death. The researchers identified a small open reading frame within the 16S rRNA gene of mitochondrial DNA — a highly unusual location for a protein-coding gene. The encoded 21-amino-acid peptide they named 'Humanin' was capable of blocking neuronal apoptosis induced by amyloid precursor protein mutations. Subsequent research by the Bharat Bhanu lab at the University of Southern California established that Humanin is the founding member of a new class of peptides called mitochondria-derived peptides (MDPs), with circulating levels that decline progressively with age.
Humanin exerts its cytoprotective effects through multiple converging pathways. It binds a tripartite receptor complex (CNTFR/WSX-1/gp130) on cell surfaces, activating JAK2/STAT3 and MAPK/ERK signaling cascades that suppress apoptosis and promote cell survival. Intracellularly, Humanin inhibits the pro-apoptotic protein BAX from translocating to the mitochondria — a critical step in programmed cell death. It also activates IGF-1 receptor signaling independently of IGF-1 itself, contributing to its insulin-sensitizing effects. In neurons, Humanin blocks amyloid-beta oligomer toxicity and tau-related cell death. Its systemic effects include improved insulin sensitivity, reduced oxidative stress markers, and reduced systemic inflammation.
- Alzheimer's disease prevention and neuronal protection from amyloid-beta toxicity
- Aging and longevity — circulating Humanin levels inversely correlate with biological aging markers
- Insulin resistance and type 2 diabetes — Humanin improves peripheral insulin sensitivity in rodent models
- Cardiovascular protection — reduces cardiomyocyte apoptosis in ischemia models
- Retinal cell protection — neuroprotection against oxidative stress in macular degeneration research
- Chemotherapy-induced peripheral neuropathy prevention
- Male fertility — Humanin protects Leydig cells from heat-induced and chemotherapy-related damage
- COVID-19 related research — mitochondrial peptides are under investigation for post-acute inflammatory states
Aging Biomarker Study
A landmark cross-sectional study published in Aging found that circulating Humanin levels were significantly lower in older adults compared to younger controls, and inversely correlated with insulin-like growth factor binding protein 3 (IGFBP-3). Centenarians had distinctly higher Humanin levels than age-matched controls, suggesting Humanin may be a biomarker of biological resilience rather than just chronological age.
Alzheimer's Model Outcomes
Multiple rodent studies using transgenic Alzheimer's models showed that Humanin administration significantly reduced amyloid plaque burden, attenuated tau phosphorylation, and preserved spatial memory performance in maze testing. The peptide was effective both preventively and after pathology was established, suggesting potential therapeutic windows.
Insulin Sensitivity Research
A study by Muzumdar et al. demonstrated that central (brain) administration of Humanin improved whole-body insulin sensitivity in rodents independently of changes in body weight or food intake, suggesting a CNS-mediated mechanism for metabolic regulation — distinct from peripherally acting insulin sensitizers.
- Human clinical trial data is extremely limited — most evidence comes from rodent and in vitro studies
- Optimal dosing for humans is not established; extrapolating from animal studies is imprecise
- Short plasma half-life of native Humanin (~10 minutes) — longer-acting analogues (HNG, S14G-Humanin) are used in research but availability varies
- Interaction with IGF-1 signaling pathways means caution is warranted in individuals with active or history of hormone-sensitive cancers
- The relationship between exogenous Humanin supplementation and endogenous production feedback loops is unknown
- Not FDA-approved; research use only
- Generally well-tolerated in research
- High doses may cause transient fatigue