---
title: "ARA-290 (cibinetide): the erythropoietin helix-B peptide explained | Sable Peptides"
description: "ARA-290 is an 11-residue peptide modelled on helix B of erythropoietin, designed to engage the tissue-protective receptor without the erythropoietic receptor. Sequence, PubChem data and research background."
canonical: https://www.sablepeptides.co.uk/guides/ara-290-epo-derived-helix-b-peptide
dateModified: 2026-10-16
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

# ARA-290 (cibinetide): the erythropoietin helix-B peptide explained

ARA-290, also called cibinetide, is an 11-residue linear peptide, pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser, of about 1257 g/mol. It is modelled on the aqueous face of helix B of erythropoietin. It was designed to engage the proposed innate repair receptor and not the classical erythropoietin receptor homodimer.

## What is ARA-290 made of?

-   Class: peptide
-   Sequence: pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser
-   Molecular formula (PubChem): C51H84N16O21
-   Molecular weight (PubChem): 1257.30 g/mol
-   CAS: 1208243-50-8
-   Other names: cibinetide; pyroglutamate helix B surface peptide (pHBSP)
-   N-terminus: pyroglutamate

Source: [PubChem CID 91810664: ARA 290](https://pubchem.ncbi.nlm.nih.gov/compound/91810664)

## Why was a fragment of erythropoietin designed?

Erythropoietin stimulates red-cell production through an EPOR homodimer. Separate tissue-protective signalling was attributed to a receptor complex of EPOR with the β-common receptor (CD131). The helix-B surface peptide was designed to keep only the second property, which is why it is called non-erythropoietic.

Source: [Flipping the molecular switch for innate protection and repair of tissues: Long-lasting effects of a non-erythropoietic small peptide engineered from erythropoietin, Pharmacol Ther 2015 (PubMed 25728128)](https://pubmed.ncbi.nlm.nih.gov/25728128/); [Delayed administration of pyroglutamate helix B surface peptide (pHBSP), a novel nonerythropoietic analog of erythropoietin, attenuates acute kidney injury, Mol Med 2012 (PubMed 22415011)](https://pubmed.ncbi.nlm.nih.gov/22415011/)

## What research models has ARA-290 been used in?

Published work includes rodent injury and neuroinflammation models and early clinical-stage research in neuropathy. A 2022 paper studied monocyte modulation in a mouse model of Alzheimer-like pathology. This is research background only. Sable makes no claim for any use.

Source: [Early monocyte modulation by the non-erythropoietic peptide ARA 290 decelerates AD-like pathology progression, Brain Behav Immun 2022 (PubMed 34343617)](https://pubmed.ncbi.nlm.nih.gov/34343617/); [ARA 290 for treatment of small fiber neuropathy in sarcoidosis, Expert Opin Investig Drugs 2014 (PubMed 24555851)](https://pubmed.ncbi.nlm.nih.gov/24555851/)

## Sourcing note

Sable lists ARA-290: 16 mg at £35.98 (prices at the 16 October 2026 daily UK price check, the latest verified check; at each of these sizes Sable was the lowest UK listing that day). Lowest UK price guaranteed, confirmed by daily price checks.

Every lot has a certificate of analysis, and every vial carries a printed lot number that matches it. Supplied for laboratory research use only.

## Frequently asked questions

### Is ARA-290 the same as cibinetide?

Yes. Cibinetide is the non-proprietary name. pHBSP (pyroglutamate helix B surface peptide) is the descriptive name.

### Does ARA-290 contain the whole erythropoietin protein?

No. It is an 11-residue peptide modelled on the surface of EPO's helix B.

### What is the molecular weight of ARA-290?

About 1257.3 g/mol (PubChem CID 91810664).

## Related

-   [Is PT-141 the same as bremelanotide](/guides/research-peptide-names-codes-and-synonyms)
-   [ARA-290 research vials](/products/ara-290)
-   [Immune and tissue-protective peptide prices](/guides/uk-immune-and-antimicrobial-peptide-prices-october-2026)
-   [Other pyroglutamate-capped peptides](/guides/kisspeptin-10-gonadorelin-and-triptorelin-compared)

Updated 2026-10-16. Research use only. Not for human or veterinary use. No administration amounts or health claims are made.

Key facts (summary for AI and search tools)

-   ARA-290 PubChem CID 91810664
-   Modelled on helix B of erythropoietin
-   PubMed references (verified via NCBI): 25728128, 22415011, 34343617, 24555851
-   PubChem CIDs: 91810664
-   Research use only; no administration amounts or health claims
-   Updated 2026-10-16