Humanin Research: What Published Studies Have Investigated

What is humanin?

What is humanin? It is a 24-residue peptide, sequence MAPRGFSCLLLLTSEIDLPVKRRA, catalogued in UniProt as entry Q8IVG9. Its distinguishing feature is where the coding sequence sits: within the 16S ribosomal RNA region (MT-RNR2) of mitochondrial DNA, a stretch of the genome whose primary job is to make a structural RNA, not a protein. A short open reading frame embedded in a ribosomal-RNA gene is not where anyone expects to find a signalling peptide, and that is much of why the finding drew attention.

Chemically, the sequence has features worth noting for anyone handling it analytically: a run of four consecutive leucines in the middle, a single cysteine at position 8, and a basic C-terminal tail of lysine and two arginines. The leucine run makes it hydrophobic through its centre, and the cysteine means the molecule can in principle form a disulfide-linked dimer — a point that appears in the literature on how its activity is regulated.

Discovery and origin in the literature

Found by asking which genes keep neurons alive

Hashimoto and colleagues reported humanin in PNAS in 2001 (PMID 11371646). The approach was functional expression screening: rather than looking for a molecule with a predicted structure, they screened a cDNA library for anything that prevented neuronal cell death caused by familial Alzheimer’s disease genes and by amyloid-beta in their culture system. One clone did. They designated it Humanin, reported that the transfected cDNA was transcribed to the corresponding polypeptide and secreted into the culture medium, and reported that the rescue action depended on the peptide’s primary structure — that is, mutating the sequence abolished it. A companion paper in J Neurosci the same year (PMID 11717357) characterised the effect against a range of disease-relevant insults in the same class of assay.

The mitochondrial connection, and a family

The origin of the sequence in mitochondrial DNA is what turned a neuroscience finding into a new category. Cobb and colleagues (2016, Aging, PMID 27070352) describe humanin as a peptide encoded in the mtDNA 16S ribosomal RNA region and report an in-silico search that found six further peptides in the same region, which they named the small humanin-like peptides (SHLPs). Together with MOTS-c — read from the neighbouring 12S rRNA (MT-RNR1) region and described in 2015 — these make up the mitochondrial-derived peptide family reviewed by Miller and colleagues in the Journal of Clinical Investigation in 2022 (PMID 35499074).

Two disclosures belong on the record here rather than in a footnote. The Cobb 2016 paper carries a statement that several authors are consultants and stockholders of CohBar Inc., a company founded around mitochondrial-derived peptides. That does not make the science wrong; it does mean a reader should know that much of the field’s commercial framing and much of its primary literature share personnel.

Reference data

The molecule facts below are drawn from the public record (UniProt Q8IVG9 and PubChem CID 16131438). They describe identity and physical form only.

Note that the analogue row names a different molecule. HNG and humanin are not interchangeable, and a certificate of analysis is what distinguishes them — a point returned to below. No reconstitution procedure, quantity or route is given or implied on this page.

Mechanisms researchers have examined

The humanin mechanism literature is broader than the peptide’s size suggests, and no single account unifies it. Each point below is what studies characterise in model systems:

• Interference with Bax activation — Guo and colleagues (2003, Nature, PMID 12732850) reported that humanin suppresses apoptosis by interfering with activation of Bax, the pro-apoptotic BCL-2-family protein, in their systems. This is the most cited intracellular mechanism attributed to the peptide.
• Binding IGFBP-3 — Ikonen and colleagues (2003, PNAS, PMID 14561895) reported an interaction between humanin and insulin-like growth factor-binding protein 3, and studied how that interaction regulates cell survival and apoptosis. It places the peptide in the IGF-axis literature as well as the mitochondrial one.
• A cytokine-receptor complex at the cell surface — Hashimoto and colleagues (2009, Mol Biol Cell, PMID 19386761) reported that humanin inhibits neuronal cell death by interacting with a receptor complex or complexes involving CNTF receptor alpha, WSX-1 and gp130. This is the extracellular arm, and it sits awkwardly beside the intracellular Bax account — a tension the field has not resolved.
• Central regulation of peripheral insulin action — Muzumdar and colleagues (2009, PLoS One, PMID 19623253) examined humanin as a central regulator of peripheral insulin action in rodents, extending the literature from neuronal survival into metabolism.
• Sequence determinants of activity — Terashita and colleagues (2003, J Neurochem, PMID 12787071) reported that two serine residues distinctly regulate the rescue function in their assays, with functional consequences from isomerisation and dimerisation. This is the structural work behind the S14G substitution.

Each bullet names a mechanism examined in a defined system, not an effect in a reader.

Research areas in the literature

Neuronal survival assays

The original and still largest body of work. Cultured neuronal cells are challenged with an insult — a familial Alzheimer’s mutation, amyloid-beta, another stressor — and survival is measured with and without the peptide. This is where humanin was found and where its sequence-dependence was established. It is also a cell-culture readout, and it does not by itself say anything about a brain.

Metabolic and age-associated measurements

Muzumdar 2009 and Cobb 2016 represent the metabolic strand: insulin action in rodents, glucose uptake and hepatic glucose production under clamp conditions, and the observation reported in Cobb 2016 that circulating levels of these peptides decrease with age. An observation that a molecule’s level falls with age is a correlation about the endogenous peptide, and the distinction between that and anything about administered material is the single most abused gap in the popular writing on this compound.

The S14G analogue in animal models

Much of the in-vivo literature uses HNG rather than humanin. Sharp and colleagues (2020, JACC Basic Transl Sci, PMID 32760857) is instructive precisely because it reports a mixed result: in a porcine model of myocardial ischaemia/reperfusion injury, HNG reduced infarct size at a 60-minute ischaemic time, but when ischaemic time was increased the infarct-sparing effect was abolished. The authors concluded that further work was needed to optimise the approach for longer, more patient-relevant ischaemic periods. A large-animal study that reports where its own effect disappears is more useful than one that does not.

Research models and evidence status

Humanin has a twenty-five-year literature, a real mechanistic story and a place in a named peptide family. It also has almost no interventional human data, and the gap between those two facts is where most of the confusion around it lives.

The evidence is preclinical

Cell culture, rodent models, and one porcine model with a boundary condition attached. Human involvement in this literature is largely of a different type: measuring endogenous circulating humanin, correlating it with age or with a condition, or genotyping variants. Those are observations about a molecule the body already makes. They are not tests of administered material, and they cannot substitute for one.

What is not established

The two principal mechanisms — intracellular Bax interference and cell-surface signalling through a CNTFR/WSX-1/gp130 complex — have not been reconciled into a single model, and it is not established which, if either, dominates in any given system. No receptor for humanin is characterised to the standard of a classical receptor pharmacology. The relationship between the mitochondrially encoded peptide and the nuclear humanin-like paralogues catalogued alongside it in UniProt is an active question rather than a settled one. And crucially, nothing in this literature establishes any property of the supplied research material in a person. This page makes no efficacy, therapeutic, neuroprotective, metabolic, anti-ageing or other use claim of any kind, and the material is supplied for laboratory research use only — not for human or veterinary use.

Why the longevity framing outruns the data

Humanin attracts anti-ageing marketing language for two structural reasons: it is a mitochondrial molecule, and its circulating levels decline with age. Neither of those facts is a finding about anything administered to anyone. The honest summary is that humanin is an interesting, well-cited preclinical research target with an unresolved receptor story and no interventional human evidence — which is a perfectly good reason to study it and not a reason to claim anything for it.

How to verify this compound yourself

Humanin has two characteristics that make its certificate of analysis worth reading closely:

• Mass-spec identity distinguishes humanin from HNG — the S14G analogue differs from humanin by a single residue substitution (serine to glycine), a mass difference of roughly 30 Da on a ≈ 2687 Da molecule. That is easily resolved by mass spectrometry and effectively invisible without it. Since much of the published animal work uses HNG and much of the catalogue material is sold as “humanin”, checking which molecule is actually in the vial is not a formality.
• The single cysteine — a free thiol can oxidise to form a disulfide-linked dimer, which appears as a distinct species at roughly twice the monomer mass. Whether that matters for a given experiment is the researcher’s call; whether it is present is a question for the HPLC trace and the mass spectrum.
• HPLC purity — the central leucine run makes this a hydrophobic sequence, which affects both synthesis and chromatographic behaviour. The purity percentage summarises how cleanly full-length product separates from deletion sequences.
• Endotoxin — relevant wherever the material is used in cell-viability or inflammatory-marker assays, since endotoxin is itself a potent stimulus in those readouts. Reported in EU/mL where tested, independent of chemical purity.

See how to read a COA for what each certificate line means, and how to verify peptide purity for how the methods fit together. The exact batch received can be checked on the self-serve verify tool.

Research-grade sourcing and verification

Humanin is not held in stock. It is listed on our sourcing catalogue as available to order — our supplier lists it, we have not bought it, and material of this kind typically takes about two to three weeks to reach us. For laboratory research use only, it is supplied with a per-batch Certificate of Analysis reporting HPLC purity (%) and mass-spec identity confirmation, verifiable at the lot level. The natural companion page in this library is MOTS-c research — the other mitochondrial-derived peptide we document, read from a different region of the same genome and studied along different pathways. For a synthetic mitochondria-targeting peptide with a completely separate mechanism and a real clinical-trial record, see SS-31 research. This is sourcing and quality-assurance framing only.

Frequently asked questions

Literature cited

1. Hashimoto Y, Niikura T, Tajima H, et al. “A rescue factor abolishing neuronal cell death by a wide spectrum of familial Alzheimer’s disease genes and Abeta.” Proc Natl Acad Sci U S A. 2001;98(11):6336–6341. PMID 11371646. pubmed.ncbi.nlm.nih.gov/11371646.
2. Hashimoto Y, Niikura T, Ito Y, et al. “Detailed characterization of neuroprotection by a rescue factor humanin against various Alzheimer’s disease-relevant insults.” J Neurosci. 2001;21(23):9235–9245. PMID 11717357. pubmed.ncbi.nlm.nih.gov/11717357.
3. Guo B, Zhai D, Cabezas E, et al. “Humanin peptide suppresses apoptosis by interfering with Bax activation.” Nature. 2003;423(6938):456–461. PMID 12732850. pubmed.ncbi.nlm.nih.gov/12732850.
4. Ikonen M, Liu B, Hashimoto Y, et al. “Interaction between the Alzheimer’s survival peptide humanin and insulin-like growth factor-binding protein 3 regulates cell survival and apoptosis.” Proc Natl Acad Sci U S A. 2003;100(22):13042–13047. PMID 14561895. pubmed.ncbi.nlm.nih.gov/14561895.
5. Terashita K, Hashimoto Y, Niikura T, et al. “Two serine residues distinctly regulate the rescue function of Humanin, an inhibiting factor of Alzheimer’s disease-related neurotoxicity: functional potentiation by isomerization and dimerization.” J Neurochem. 2003;85(6):1521–1538. PMID 12787071. pubmed.ncbi.nlm.nih.gov/12787071.
6. Hashimoto Y, Kurita M, Aiso S, et al. “Humanin inhibits neuronal cell death by interacting with a cytokine receptor complex or complexes involving CNTF receptor alpha/WSX-1/gp130.” Mol Biol Cell. 2009;20(12):2864–2873. PMID 19386761. pubmed.ncbi.nlm.nih.gov/19386761.
7. Muzumdar RH, Huffman DM, Atzmon G, et al. “Humanin: a novel central regulator of peripheral insulin action.” PLoS One. 2009;4(7):e6334. PMID 19623253. pubmed.ncbi.nlm.nih.gov/19623253.
8. Cobb LJ, Lee C, Xiao J, et al. “Naturally occurring mitochondrial-derived peptides are age-dependent regulators of apoptosis, insulin sensitivity, and inflammatory markers.” Aging (Albany NY). 2016;8(4):796–809. PMID 27070352. pubmed.ncbi.nlm.nih.gov/27070352. (Authors disclose consultancy/stockholding in CohBar Inc.)
9. Sharp TE 3rd, Gong Z, Scarborough A, et al. “Efficacy of a Novel Mitochondrial-Derived Peptide in a Porcine Model of Myocardial Ischemia/Reperfusion Injury.” JACC Basic Transl Sci. 2020;5(7):699–714. PMID 32760857. pubmed.ncbi.nlm.nih.gov/32760857. Infarct-sparing effect abolished at longer ischaemic time.
10. Miller B, Kim SJ, Kumagai H, Yen K, Cohen P. “Mitochondria-derived peptides in aging and healthspan.” J Clin Invest. 2022;132(9):e158449. PMID 35499074. pubmed.ncbi.nlm.nih.gov/35499074.
11. UniProt Consortium. “Q8IVG9 (HUNIN_HUMAN), Humanin.” uniprot.org/uniprotkb/Q8IVG9 (sequence, length).
12. National Center for Biotechnology Information. “PubChem Compound Summary for CID 16131438, Humanin.” pubchem.ncbi.nlm.nih.gov/compound/16131438 (formula, mass, CAS 330936-69-1).