ARA-290 · Research brief
ARA-290 Peptide (Cibinetide): Research and Purity Data
Short answer
Erythropoietin earned its reputation doing one thing: pushing bone marrow to produce red blood cells. ARA-290 was engineered to delete that function entirely and keep the quieter signalling the hormone was doing in injured tissue. Our team reads certificates of analysis and primary literature side by side every week, and ARA-290 is one of the compounds where those two documents…
Key takeaways
- ARA-290, also called cibinetide, is an 11-amino-acid peptide derived from helix B of erythropoietin that binds the EPOR/CD131 innate repair receptor without activating the EPOR homodimer responsible for red blood cell production.
- Receptor dependence is supported by direct evidence, including a 2024 CNS Neuroscience and Therapeutics study reporting that brain tissue protection in mice with cerebral ischaemic stroke was mediated through the beta-common receptor.
- Published ARA-290 work spans colitis, lupus, cisplatin nephrotoxicity, apical periodontitis, cardiac inflammation and chronic stress models, and is overwhelmingly preclinical.
- As a small unmodified linear peptide, circulating half-life is measured in minutes, and any precise figure quoted without a primary citation should be treated as unverified.
- Verification requires three things together: RP-HPLC purity with a chromatogram, mass spectrometry identity confirmation, and a batch-specific certificate of analysis showing net peptide content rather than gross weight.
- The compound has no FDA approval for any indication and is supplied strictly as a research chemical.
Erythropoietin earned its reputation doing one thing: pushing bone marrow to produce red blood cells. ARA-290 was engineered to delete that function entirely and keep the quieter signalling the hormone was doing in injured tissue.
Our team reads certificates of analysis and primary literature side by side every week, and ARA-290 is one of the compounds where those two documents most often contradict the marketing copy sitting between them. What follows is the published record, the gaps in it, and the bench checks that separate a verified vial from an unverified one.
What is ARA-290?
ARA-290, also known as cibinetide, is an 11-amino-acid peptide modelled on helix B of the erythropoietin molecule. It binds the innate repair receptor, a heterodimer of the erythropoietin receptor and CD131, without stimulating red blood cell production. It is supplied for laboratory research only, and the published literature remains dominated by rodent models.
The oversimplification worth correcting early: ARA-290 is not erythropoietin with the blood effects filtered out. It engages a structurally distinct receptor complex that erythropoietin itself only reaches at high local concentrations during tissue injury, which is why the research profile sits in inflammation and nerve biology rather than haematology. This page covers the receptor mechanism, what peer-reviewed work reports across neuropathy and inflammation models, what the record does and does not say about pharmacokinetics and adverse findings, and how a vial is verified by HPLC and mass spectrometry.
What is ARA-290, and where does the molecule come from?
ARA-290 is an 11-residue linear peptide mapped to the outer face of helix B of erythropoietin (EPO), the kidney-derived hormone that drives erythropoiesis. The face of EPO responsible for red blood cell signalling binds a homodimer of two EPO receptor subunits. The helix B surface that ARA-290 reproduces does not touch that interface at all, which is the structural reason a peptide copied from EPO can engage tissue-protective signalling while leaving haematocrit untouched.
Cibinetide is the international nonproprietary name for the same molecule. ARA-290, ARA290, cibinetide and helix B surface peptide all describe one compound, and catalogues use the names interchangeably. We unpack that naming history in more detail in our breakdown of ARA-290 and cibinetide terminology, because researchers regularly assume they are shopping for two different products.
Interest in non-haematopoietic EPO derivatives was substantial enough to draw editorial attention in Molecular Medicine in 2013, and the programme that followed has been narrow but persistent: one small peptide, one receptor complex, a long list of inflammatory and neuropathic animal models. Honestly, the single most common question we field about ARA-290 is whether it raises red cell counts. The design intent is the opposite, and the receptor pharmacology explains why. Our general research FAQ hub collects the rest of those recurring questions.
How does the peptide work at the receptor level?
The innate repair receptor (IRR) is a heterodimer: one erythropoietin receptor subunit paired with CD131, the beta-common receptor shared by GM-CSF, IL-3 and IL-5 signalling. ARA-290 was designed as a selective ligand for that specific pairing rather than the EPOR homodimer that governs erythropoiesis. A 2023 paper in Inflammation examining ARA-290 as a specific ligand for the EPO/CD131 heteroreceptor investigated apoptosis and inflammation pathways in cisplatin-induced nephrotoxicity.
Receptor dependence has been tested directly rather than assumed. A 2024 study in CNS Neuroscience and Therapeutics reported that brain tissue protection by ARA-290 in mice with cerebral ischaemic stroke was mediated through the beta-common receptor. That is the type of evidence that separates a described mechanism from a correlation.
Downstream, signalling converges on well-mapped inflammatory machinery. A 2025 International Immunopharmacology paper on pegmolesatide, a separate EPO-related compound, describes EPOR-CD131-dependent JAK2/STAT3 signalling in cardiomyocyte hypertrophy, tracing the transduction route this receptor complex uses. A 2025 International Dental Journal study reported ARA-290 attenuating apical periodontitis via SIRT1/NF-kB/IL-1beta pathway modulation, which places NF-kB suppression and IL-1beta reduction inside the same mechanistic story. Transcriptional consequences are covered further in our notes on gene expression and mechanism research and the broader chronic pain mechanism literature.
What does the neuropathy and pain literature report?
Small fibre neuropathy is where this peptide has its deepest paper trail. A 2014 review in Expert Opinion on Investigational Drugs discussed ARA 290 for small fibre neuropathy in sarcoidosis, and a 2016 paper in Pain Reports framed the wider strategy of targeting the innate repair receptor in neuropathy. Both sit inside a field that has struggled badly for translatable candidates, a point made explicitly in a 2021 Expert Opinion on Investigational Drugs commentary on the time to develop treatments for diabetic neuropathy.
The mechanistic logic researchers give for ARA-290 in these models is that nerve fibre damage in metabolic and inflammatory neuropathy is driven substantially by local innate immune activation rather than by the axon alone. Dampen the macrophage and cytokine response at the IRR, the reasoning goes, and the regenerative capacity of small fibres has room to operate.
That logic has not produced a licensed product, and nothing in the peer-reviewed record supports describing ARA-290 as an established intervention for any neuropathic condition. Our deeper reviews of the diabetic neuropathy mechanism literature, the chemotherapy-induced neuropathy research, the chemotherapy neuropathy evidence base and the fibromyalgia research mechanism each separate what was modelled in animals from what was observed in people. Related metabolic work is summarised in our overview of diabetes complications research.
What does the inflammation and organ-protection literature report?
Outside the nervous system, the published work clusters around innate immune suppression and organ injury models, almost entirely in rodents. A 2017 Scientific Reports paper found that cibinetide dampens innate immune cell functions and ameliorates the course of experimental colitis. A 2018 paper in the Journal of Cellular and Molecular Medicine reported that a non-erythropoietic erythropoietin-derived peptide protected mice from systemic lupus erythematosus.
Cardiac and ageing models add another line. A 2022 Frontiers in Cardiovascular Medicine study described a small erythropoietin-derived non-hematopoietic peptide reducing cardiac inflammation, attenuating age-associated declines in heart function and prolonging healthspan in animals. Behavioural neuroinflammation has been examined too: a 2022 Frontiers in Pharmacology paper reported that ARA-290 ameliorated chronic stress-induced depression-like behaviour and inflammation in mice.
Read together, the pattern is consistent and worth stating plainly: across colitis, lupus, renal injury, stroke, periodontitis and chronic stress models, the reported effect is anti-inflammatory and tissue-protective rather than growth-promoting. That breadth is genuinely interesting and also a caution. A compound that modulates one receptor across that many tissues deserves more translational scrutiny, not less. We compare the rodent record against the human record directly in our review of animal versus human ARA-290 research and in our survey of neuroinflammation animal studies.
What side effects and unknowns does the research describe?
The honest summary is that the adverse-event picture for this peptide is thin rather than reassuring. There is no large, long-duration safety database of the kind that exists for approved drugs, and the published literature is weighted toward efficacy endpoints in animals. The absence of reported problems in small early-phase work is not equivalent to a demonstrated safety profile.
The selectivity argument cuts both ways. Avoiding EPOR homodimer activation is what keeps haematocrit, blood viscosity and thrombotic risk out of the conversation, which is the central pharmacological advantage over erythropoietin itself. But the same colitis research that credits the peptide with dampening innate immune cell function describes a mechanism that, in a different context, would blunt host defence. That is an inference from mechanism, not a documented adverse event, and it should be labelled as such.
Unknowns researchers flag most often include long-term effects of sustained IRR engagement, interactions with the shared CD131 subunit used by GM-CSF, IL-3 and IL-5 signalling, immunogenicity over extended exposure, and the near-total absence of chronic-exposure toxicology in the public record. Our notes on contraindications and safety limits, the laboratory markers researchers monitor and biomarkers and clinical indicators go through what published work actually measured.
What is known about half-life and pharmacokinetics?
Short. That is the accurate one-word answer, and the specifics deserve care. ARA-290 is a small linear peptide with no protective modifications, no PEGylation and no D-amino acid substitutions, so it is exposed to the same serum peptidase activity that clears other 11-residue peptides within minutes rather than hours. Circulating half-life reported in the literature sits on the order of minutes.
Here is the part most ARA-290 summaries skip. None of the peer-reviewed sources cited on this page report a numeric plasma half-life, so any precise figure quoted in a product listing should be traced to its primary source before it is repeated in a methods section. A vendor-stated number without a citation is marketing, not pharmacokinetic data.
The more useful concept is the gap between pharmacokinetics and pharmacodynamics. Receptor-mediated signalling through the EPOR-CD131 heteroreceptor triggers transcriptional changes, including the NF-kB and SIRT1 modulation reported in the periodontitis work, that persist long after the peptide itself has been cleared. Plasma clearance and biological effect are different clocks. Stability in solution is a separate issue again, because a peptide degrading in a reconstituted vial loses potency independently of anything happening in a model organism. That problem is covered in our write-up on reconstituted storage and degradation.
How do researchers verify a vial before it reaches the bench?
Three documents answer three different questions, and conflating them is the most common sourcing error we see. Reverse-phase HPLC answers how much of the material is the target peptide, typically reported as area percentage at a stated wavelength. Mass spectrometry, usually ESI-MS or MALDI-TOF, answers whether the molecule present is the right molecule by matching observed mass against the theoretical mass of the sequence. A certificate of analysis ties both to a specific synthesis batch.
A purity figure without an attached chromatogram is a number, not evidence. A chromatogram without a batch number cannot be matched to the vial in hand. And a mass spectrum is the only one of the three that catches a correctly purified but wrong peptide, which is precisely the failure mode HPLC alone will never detect.
The detail almost no sourcing guide mentions: gross peptide weight and net peptide content are not the same number. Lyophilised peptides carry residual water and counterions left from purification, commonly trifluoroacetate, and that mass is part of the powder on the scale. A certificate reporting only gross weight overstates how much peptide is actually in the vial. Net peptide content, determined by amino acid analysis or nitrogen determination, is the figure that matters for reproducible work.
Real Peptides supplies ARA-290 for laboratory research with a published batch certificate, and every document is available through our certificate of analysis library. Buyers comparing documentation standards across suppliers can start with our overview of research-grade ARA-290 availability.
How is this peptide handled and stored in a laboratory?
Lyophilised ARA-290 is stable as a dry powder under cold, dark, dry conditions, and the standard laboratory practice for research peptides is storage at minus 20 degrees Celsius or lower, protected from light and moisture. The dry state is the stable state. Everything that goes wrong tends to go wrong after reconstitution.
Once an aqueous diluent is introduced, hydrolysis and oxidation clocks start. Reconstituted peptide solutions are held refrigerated at 2 to 8 degrees Celsius and treated as short-lived laboratory reagents. Repeated freeze-thaw cycling is the quiet potency killer, because each cycle concentrates solutes at the ice interface and drives aggregation, which is why aliquoting into single-use volumes at the point of reconstitution is standard practice.
Two physical checks are worth running before anything else. A lyophilised cake that has collapsed into a thin glassy film at the bottom of the vial suggests a temperature excursion in transit. Visible particulate or cloudiness after reconstitution in a clear diluent suggests aggregation. Neither observation tells you potency, and that is the point: no visual inspection substitutes for a chromatogram. Our detailed treatment of storage, degradation and potency covers the handling variables in sequence.
What is its legal and research-use-only status?
ARA-290 is not an approved drug. It has no FDA marketing authorisation for any condition, it is not a licensed veterinary product, and it has not completed the regulatory pathway that would allow it to be described as a therapy. It is a research chemical, legal to buy and possess for laboratory use, and it is not a controlled substance.
All compounds discussed on this page are sold for research use only and are not for human consumption.
That framing is not a formality. Research-use-only material is manufactured to analytical specifications, not to pharmaceutical sterility and endotoxin standards, and the documentation chain reflects laboratory requirements rather than clinical ones. Institutions purchasing ARA-290 should route it through the same handling, record-keeping and disposal procedures applied to any other uncharacterised research compound. If a question about an animal's health is what brought you to this page, talk to your veterinarian, because a research peptide is not a veterinary medicine and should never be treated as one. The information here is educational and describes published literature only.
How does it compare with related research compounds?
The table below sets ARA-290 against the parent hormone it was derived from and two other peptides frequently examined in inflammation research, so the differences in target and evidence maturity are visible side by side.
| Compound | Molecule type and primary target | What the peer-reviewed evidence covers | Professional assessment for a research programme |
|---|---|---|---|
| ARA-290 (cibinetide) | 11-amino-acid EPO helix B derivative; selective ligand for the EPOR/CD131 innate repair receptor | Rodent models across colitis, lupus, cerebral ischaemia, nephrotoxicity, periodontitis and chronic stress, plus limited early human work in small fibre neuropathy | The cleanest receptor story in this group, with mechanism confirmed by beta-common receptor dependence, but translational data remains the weakest link |
| Erythropoietin (epoetin alfa) | 165-amino-acid glycoprotein hormone; EPOR homodimer | Extensive clinical literature in anaemia, plus tissue-protection findings that motivated the derivative programme | Approved and fully characterised, but erythropoietic activity, raised haematocrit and thrombotic risk make it unsuitable as a chronic anti-inflammatory research tool |
| BPC-157 | 15-amino-acid gastric peptide fragment; multiple proposed pathways including angiogenic and nitric oxide signalling | Broad rodent literature across tendon, gut and nerve injury models; no completed large human trials and no approval | Mechanistically diffuse compared with a single-receptor ligand, which makes attributing an observed effect to a defined pathway substantially harder |
| KPV | Tripeptide fragment of alpha-MSH; melanocortin receptor and NF-kB related anti-inflammatory signalling | Preclinical inflammatory bowel and mucosal inflammation models; limited human data | A useful comparator when the research question is NF-kB suppression specifically, though the published base is narrower than the EPO-derivative literature |
Our side-by-side reviews of research peptide alternatives for 2026, how it compares with other research peptides and combination study designs go further into selection criteria.
How we researched this page
Every study claim here links directly to its PubMed record, and claims that could not be matched to an indexed, peer-reviewed source were cut rather than hedged. We did not run first-party assays for this article, and no purity, potency or half-life figure stated above originates from in-house testing.
The literature search was restricted to peer-reviewed publications indexed in PubMed. Vendor blogs, forum reports, anecdotal accounts and secondary summaries were excluded entirely, including where they would have supported a more enthusiastic framing. Where a cited paper examines a related compound rather than ARA-290 itself, that distinction is stated in the sentence rather than buried in the citation.
What if: common laboratory sourcing scenarios
What if a certificate of analysis has no batch number?
Treat the document as unlinked to the vial and request a batch-specific replacement. A generic certificate demonstrates that the supplier once tested something, not that this particular synthesis run passed. Synthesis batches vary in deletion sequences, truncation products and residual solvent, which is precisely why batch-level documentation exists. Without a lot identifier, a purity figure cannot be reconciled against the material in hand, and any downstream result becomes impossible to reproduce.
What if the HPLC purity figure arrives without a chromatogram?
Ask for the raw trace, including the detection wavelength and gradient conditions. A reported percentage is a summary of a chromatogram, and summaries can omit the information that matters most: shoulder peaks indicating closely eluting impurities, baseline drift, or integration choices that flatter the headline number. Detection wavelength matters too, since peptides lacking aromatic residues absorb weakly at 280 nanometres and are typically monitored near 214 nanometres at the peptide bond.
What if two suppliers list ARA-290 and cibinetide as separate products?
They are the same molecule, and the listings should be compared on documentation rather than name. Cibinetide is the international nonproprietary name; ARA-290 is the development code. Catalogue systems sometimes carry both as distinct entries, which creates the impression of two compounds with different properties. Compare the stated sequence, the molecular weight on the mass spectrometry report and the net peptide content, because those three data points resolve the question immediately.
What if the lyophilised cake looks collapsed on arrival?
Document it photographically and raise it with the supplier before reconstituting anything. A collapsed or glassy film instead of a structured cake points to a temperature excursion during shipping or a problem at the lyophilisation stage. Appearance alone does not establish degradation, and it cannot be assumed to be harmless either. The only resolution is analytical, which means re-testing or replacement rather than visual judgement.
The blunt truth about what this peptide can and cannot claim
Let's be direct about this: ARA-290 has an unusually clean mechanism and an unusually thin translational record, and those two facts are often presented as one. The receptor biology is well characterised, confirmed by beta-common receptor dependence studies, and genuinely interesting. The human evidence base is small, early-phase and narrow. Anyone describing this peptide as an established intervention for neuropathy, fatigue or inflammation is describing something the literature does not contain. Mechanistic elegance is not clinical validation, and in peptide research those two things get confused more often than almost anywhere else in biology.
Further reading across our research library covers before-and-after research framing, why before-and-after claims circulate without evidence, chronic pain research mechanisms, the chronic pain study record, fibromyalgia research mechanisms and trials, research application questions, and timelines reported in diabetes complications research.
ARA-290 occupies an unusual position in peptide science: a compound defined by what it deliberately does not do. Subtractive design is rare, and it produces a research tool that is far easier to interpret than a compound hitting six pathways at once, because a single receptor complex means an observed effect has one obvious place to come from. That clarity is the asset. It also raises the bar, since a clean mechanism offers nowhere to hide when a model fails to replicate. Read the chromatogram before the study abstract, and the rest of the picture tends to come into focus.
References
Peer-reviewed sources on ARA-290 (Cibinetide) indexed in PubMed, listed for research context. Real Peptides supplies ARA-290 (Cibinetide) for laboratory research use only.
- Mechanistic Approach for Protective Effect of ARA290, a Specific Ligand for the Erythropoietin/CD131 Heteroreceptor, against Cisplatin-Induced Nephrotoxicity, the Involvement of Apoptosis and Inflammation Pathways. Inflammation, 2023. PMID 36085231. doi:10.1007/s10753-022-01737-7
- Early monocyte modulation by the non-erythropoietic peptide ARA 290 decelerates AD-like pathology progression. Brain, behavior, and immunity, 2022. PMID 34343617. doi:10.1016/j.bbi.2021.07.016
- Synthesis and evaluation of (99m)Tc-DOTA-ARA-290 as potential SPECT tracer for targeting cardiac ischemic region. Iranian journal of basic medical sciences, 2021. PMID 35317117. doi:10.22038/IJBMS.2021.57565.12799
- The Non-Erythropoietic EPO Analogue Cibinetide Inhibits Osteoclastogenesis In Vitro and Increases Bone Mineral Density in Mice. International journal of molecular sciences, 2021. PMID 35008482. doi:10.3390/ijms23010055
- Cibinetide Protects Isolated Human Islets in a Stressful Environment and Improves Engraftment in the Perspective of Intra Portal Islet Transplantation. Cell transplantation, 2021. PMID 34498509. doi:10.1177/09636897211039739
- An engineered non-erythropoietic erythropoietin-derived peptide, ARA290, attenuates doxorubicin induced genotoxicity and oxidative stress. Toxicology in vitro : an international journal published in association with BIBRA, 2020. PMID 32335150. doi:10.1016/j.tiv.2020.104864
- Improvement of Islet Allograft Function Using Cibinetide, an Innate Repair Receptor Ligand. Transplantation, 2020. PMID 32345869. doi:10.1097/TP.0000000000003284
- A Phase 2 Clinical Trial on the Use of Cibinetide for the Treatment of Diabetic Macular Edema. Journal of clinical medicine, 2020. PMID 32674280. doi:10.3390/jcm9072225
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