Research Use Only. The information presented here is for scientific and educational purposes. These compounds are not intended for human consumption, self-administration, or therapeutic use.
Introduction
ARA-290, also known as cibinetide, is a short synthetic peptide of eleven amino acids that appears repeatedly in regenerative and neuroscience research literature. It is derived from a specific region of erythropoietin (EPO) called the Helix B domain, and it was engineered to interact with a tissue-protective signaling pathway without triggering the red blood cell production associated with the parent hormone. In laboratory settings, ARA-290 is studied primarily as a selective ligand for the innate repair receptor (IRR), a receptor complex that becomes more prominent on stressed or injured tissue.
This overview summarizes how ARA-290 is described in preclinical and in-vitro research: its molecular identity, its relationship to erythropoietin, the receptor biology that defines its studied mechanism, and the animal-model contexts in which it has been examined, including peripheral neuropathy paradigms. All information below reflects research use only, not for human consumption, and every mechanism described here is framed strictly within experimental, non-clinical settings.
What Is ARA-290 (Cibinetide)?
ARA-290 belongs to a class of compounds often called non-erythropoietic erythropoietin derivatives. Erythropoietin is best known as the hormone that regulates red blood cell formation, but a long line of research has suggested it also carries a separate, tissue-protective signaling role. Investigators mapped this protective activity to a small surface region of the EPO molecule, the Helix B domain, and then synthesized peptides that reproduce it. ARA-290 is one such peptide, sometimes referenced in the literature as the Helix B Surface Peptide (pHBSP).
Molecular Identity
The values below reflect commonly reported laboratory attributes and are provided for comparison only.
| Attribute | Reported detail |
|---|---|
| Research designation | ARA-290 (cibinetide) |
| Alternate references | pHBSP, Helix B Surface Peptide |
| Peptide class | Non-erythropoietic erythropoietin-derived peptide |
| Amino acid length | 11 residues |
| Approximate molecular weight | ~1257 Da (vendor-reported) |
| Parent molecule | Helix B domain of erythropoietin |
| Primary studied target | Innate repair receptor (EPOR and CD131 complex) |
Why “Non-Erythropoietic” Matters
A defining feature in the research characterization of ARA-290 is that it does not meaningfully bind the classical EPO receptor homodimer that drives erythropoiesis. In animal studies, this separation is what allows investigators to probe EPO’s tissue-protective signaling without the increases in hematocrit and red cell mass that limit full-length erythropoietin as a research probe. This selectivity is central to why ARA-290 is studied as a distinct molecule rather than simply as an EPO fragment.
The Innate Repair Receptor
The innate repair receptor (IRR) is the conceptual centerpiece of ARA-290 research. Classical erythropoietin signaling proceeds through a receptor homodimer, two copies of the EPO receptor (EPOR) paired together, which activates the pathways responsible for red blood cell formation. Tissue-protective signaling, by contrast, is attributed in the research literature to a different assembly: a heterocomplex that combines the EPO receptor with the beta common receptor (CD131), a subunit also shared by several cytokine receptors.
A Receptor That Appears on Injured Tissue
A frequently cited property of the innate repair receptor in experimental work is that it is not constitutively abundant. Instead, its expression is reported to increase in tissues under metabolic stress, inflammation, or injury. In cell and animal models, this pattern has been interpreted to mean that ARA-290 signaling is directed toward damaged tissue while leaving healthy, unstressed tissue largely unaffected. Researchers describe downstream effects in these models that include modulation of inflammatory signaling and support for cellular survival pathways.
Distinguishing the Two Pathways
Because ARA-290 engages the heterocomplex rather than the erythropoietic homodimer, preclinical studies use it as a tool to separate the two arms of EPO biology. This distinction is why the compound is categorized within regenerative and tissue-protective peptide research rather than hematology research, and it frames essentially every downstream question investigators ask about the molecule.
ARA-290 in Neuropathy and Tissue-Repair Models
Much of the published interest in ARA-290 comes from preclinical neuropathy research. Peripheral neuropathy, meaning damage or dysfunction of the small nerve fibers, has been modeled in animals and in cell culture, and ARA-290 has been used in these systems to study whether innate-repair-receptor activation influences nerve fiber integrity and inflammatory tone. All of the observations described here derive from animal models and laboratory systems, not from human treatment outcomes.
Peripheral Neuropathy Models
In rodent models of nerve injury and metabolic stress, investigators have examined markers associated with small nerve fiber density, neuroinflammation, and pain-related behavior after administration of ARA-290. The research framing centers on the hypothesis that engaging the innate repair receptor may shift injured neural tissue toward repair-associated signaling. These are mechanistic, exploratory studies conducted in animal and in-vitro systems; they characterize a pathway rather than establish any outcome in humans.
Inflammation and Tissue Protection
Beyond neural tissue, ARA-290 has been studied in animal and in-vitro models of inflammation, ischemic stress, and wound repair. A recurring theme is the modulation of pro-inflammatory signaling alongside support of the tissue microenvironment during recovery. For readers surveying this space, Rejuven8 maintains a broader comparison of recovery and tissue-repair research peptides that situates EPO-derived peptides alongside other regenerative research compounds.
Related Repair Peptides and Research Handling
ARA-290 is one of several peptides studied within tissue-repair and regenerative research, and it is often discussed alongside compounds that act through entirely different mechanisms, which makes side-by-side context useful. The values below reflect commonly reported laboratory attributes and are provided for comparison only.
| Research peptide | Reported origin or class | Primary studied pathway |
|---|---|---|
| ARA-290 (cibinetide) | EPO Helix B-derived, 11 residues | Innate repair receptor (EPOR and CD131) |
| BPC-157 | Gastric peptide fragment | Angiogenesis and tissue-repair signaling |
| TB-500 | Thymosin beta-4 fragment | Actin regulation and cell migration |
| GHK-Cu | Copper-binding tripeptide | Remodeling and regenerative gene expression |
Unlike ARA-290, these comparison peptides are characterized in the research literature through their own distinct mechanisms and are stocked as research materials. ARA-290 itself is not part of the current Rejuven8 catalog; researchers interested in adjacent regenerative compounds can review the full catalog of lab-tested research peptides.
Purity and Documentation
For any peptide used in a research setting, material quality determines whether results are interpretable. Independent analytical testing, reported on a certificate of analysis, is the standard reference for identity and purity. The Rejuven8 guide to reading a peptide COA explains how to interpret mass spectrometry and HPLC data so that a research batch can be evaluated before any experiment begins. These practices apply to research handling only and carry no implication of human use.
Frequently Asked Questions
What is ARA-290 (cibinetide)?
ARA-290, also called cibinetide, is an eleven-amino-acid peptide derived from the Helix B domain of erythropoietin. In research, it is studied as a selective, non-erythropoietic ligand for the innate repair receptor, a tissue-protective receptor complex. It is a research compound only and is not intended for human consumption.
What is the innate repair receptor?
The innate repair receptor is a receptor complex made up of the erythropoietin receptor (EPOR) paired with the beta common receptor (CD131). In experimental models, its expression increases on injured or inflamed tissue, and it is described as mediating erythropoietin’s tissue-protective signaling rather than red blood cell production.
How is ARA-290 related to erythropoietin?
ARA-290 reproduces a small surface region of the erythropoietin molecule, the Helix B domain, that is associated in research with tissue protection. It is designed to engage that protective pathway while avoiding the receptor interaction that drives red blood cell formation.
Does ARA-290 raise red blood cell counts like EPO?
In animal research, ARA-290 is characterized as non-erythropoietic, meaning it does not meaningfully activate the classical EPO receptor homodimer responsible for erythropoiesis. This property is one of the main reasons it is studied separately from full-length erythropoietin.
What neuropathy models has ARA-290 been studied in?
Preclinical research has examined ARA-290 in rodent and cell-culture models of peripheral and small fiber neuropathy, where investigators study markers of nerve fiber integrity, neuroinflammation, and pain-related behavior. These are exploratory, mechanistic studies conducted in animal and in-vitro systems only.
Is ARA-290 available for human use?
No. ARA-290 is described here strictly as a research compound. It is for research use only, not for human consumption, self-administration, or therapeutic use, and none of the mechanisms discussed represent established human outcomes.
References and Further Reading
- Brines and Cerami, foundational research on tissue-protective, non-erythropoietic erythropoietin derivatives and the innate repair receptor. PubMed: ARA-290 innate repair receptor
- Studies of cibinetide (ARA-290) in neuropathic and neuroinflammatory research models. PubMed: cibinetide neuropathy
- Research on the beta common receptor (CD131) in erythropoietin-mediated tissue protection. PubMed: beta common receptor erythropoietin tissue protection
- Characterization of the Helix B Surface Peptide (pHBSP) derived from erythropoietin. PubMed: helix B surface peptide erythropoietin
- Preclinical investigations of ARA-290 in diabetic peripheral neuropathy models. PubMed: ARA-290 diabetic neuropathy
- Experimental research on ARA-290 and small fiber neuropathy. PubMed: cibinetide small fiber neuropathy
- Reviews of non-erythropoietic erythropoietin analogues in inflammation and tissue repair. PubMed: non-erythropoietic erythropoietin tissue repair
