# ARA-290 Spray

> Research use only. Not for human or veterinary use. Supplied by Veracue Labs.

- Page: https://veracuelabs.com/product/ara-290-spray
- Category: Nasal Sprays
- Sizes and prices in USD: 10 mg at $65.99
- Certificate of analysis: none posted on the page. Request one for a specific lot at https://veracuelabs.com/contact-us.
- Prices are a snapshot from 2026-10-17. The product page shows the current price.

## Overview

ARA-290 Spray is a spray-dispensed research format of an 11-residue peptide, pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser, modeled on the helix B surface of erythropoietin and also known as cibinetide or pHBSP. Reference values for the free peptide are the formula C51H84N16O21, an average mass of 1257.3 g/mol, a monoisotopic mass of 1256.5997 Da and CAS 1208243-50-8. It is a short synthetic peptide and not erythropoietin itself. Offered as a 10 mg bottle with 45 sprays per bottle, for laboratory research use only.

## Product Details

### Peptide Overview

ARA-290 is a linear synthetic peptide of eleven residues. The chain starts with a pyroglutamate cap and reads pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser, which one-letter notation shortens to pGlu-EQLERALNSS. The design is modeled on the surface of helix B in erythropoietin (EPO), the 165-amino-acid glycoprotein hormone that serves as its structural origin.

The bottle is spray-dispensed, 10 mg in size, with 45 sprays per bottle. Veracue sells it for laboratory research use only.

### Identifiers and Reference Values

Listing name: ARA-290 Spray
Peptide: ARA-290 (cibinetide)
Other names: ARA290, ARA 290, pHBSP, pyroglutamate helix B surface peptide
Chain: 11 residues, linear, N-terminal pyroglutamate
Three-letter sequence: pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser
One-letter notation: pGlu-EQLERALNSS (PubChem writes XEQLERALNSS, with X standing for pyroglutamate)
Molecular formula: C51H84N16O21
Average molecular weight: 1257.3 g/mol
Monoisotopic mass: 1256.5997 Da
CAS Registry Number: 1208243-50-8
PubChem CID: 91810664
UNII: 9W5677JKDA
Dispensing format: Spray-dispensed bottle, 45 sprays per bottle
Size offered: 10 mg
Research designation: Research Use Only

Identifiers and masses describe the free peptide as a reference structure taken from public chemical databases, which also list acetate and TFA salt forms of the same peptide. Salt form, net peptide content, purity and lot results belong to each lot, and the documentation for a given bottle can be requested through the contact page.

### Reading the Name on a Label

Three labels circulate for this peptide. ARA-290 is the name used across most research papers, cibinetide is the name used in chemical databases, and pHBSP is the older descriptive code for the pyroglutamate helix B surface peptide. Hyphen and spacing variants such as ARA290 or ARA 290 change nothing about the molecule.

Because supplier naming is loose, the sequence, the formula and the CAS number together are a firmer test of identity than the name printed on a bottle.

## Research Focus & Mechanism Overview

### Where the Design Comes From

EPO is a glycosylated hormone of 165 amino acids with a helical-bundle fold. ARA-290 represents only the exposed surface of one helix of that fold, helix B, as an eleven-residue chain capped with pyroglutamate. It is roughly fifteen times shorter than EPO and carries no carbohydrate.

The link between the two molecules is structural origin only. Findings, handling history or properties of EPO do not carry over to the peptide, and the reverse holds as well.

### Receptor Models, Stated at the Assay Level

EPO’s classical receptor is a homodimer of two EPO receptor chains (EPOR/EPOR). A second, proposed complex pairs one EPOR chain with the beta-common receptor, CD131 (βcR), and has been called the innate repair receptor (IRR). ARA-290 was conceived within that second model, as a helix B surface mimic for probing IRR-linked signaling separately from EPOR homodimer signaling.

The model is not settled. Biophysical binding experiments on the purified extracellular domains of EPOR and βcR, run with and without EPO and with and without ARA-290, did not detect a direct association between the two domains. The same work noted that transmembrane and intracellular regions were outside the experiment, so whether the receptors pair inside cells is still debated.

Component: Role in the proposed model

EPOR homodimer: Classical EPO receptor on erythroid precursor cells, the pairing the peptide was not designed around
EPOR with beta-common receptor (CD131): Proposed innate repair receptor (IRR)
Isolated extracellular domain binding assays: No direct EPOR to βcR association detected
Overall status: Proposed research framework, not a confirmed mechanism for every reported readout

### Reading Reports on This Peptide

- Note which model system and which comparator the report used.
- Note which endpoint was measured, since each report defines its own.
- Look for the chemical form used (free peptide, acetate or TFA salt), because many reports leave it out and then cannot be matched to a lot.
- Treat the label non-erythropoietic as naming one measured property of red-cell-lineage assays, not as a broad descriptor of the peptide.

### Look-Alike Compounds and How Identity Separates Them

Several short peptides sit beside ARA-290 in catalogs and search results, often under one shared category heading. They differ in origin and length, and their masses differ enough that a mass spectrum tells them apart immediately.

Compound: Length and size: Structural origin

ARA-290 (cibinetide): 11 residues, about 1257.3 g/mol: Modeled on the helix B surface of erythropoietin
Erythropoietin (EPO): 165 amino acids, glycosylated: Parent protein with a helical-bundle fold
BPC-157: 15 residues, about 1419.5 g/mol: Synthetic peptide inspired by a partial sequence identified in gastric juice
KPV: 3 residues (Lys-Pro-Val): Fragment derived from alpha-melanocyte-stimulating hormone
TB-500: Market name for a fragment of about 7 residues: Associated with thymosin beta-4, a 43-residue protein; usage of the name varies
SS-31: 4 residues: Synthetic aromatic-cationic tetrapeptide designed to target mitochondria

Within ARA-290 itself the N-terminus is the identity detail to check. The pyroglutamate ring forms when an open N-terminal glutamate loses a water molecule, so an uncyclized chain reads about 18 Da higher. The sequence also holds one Gln and one Asn, each a site where a +0.98 Da deamidation shift can occur. Only a mass spectrum tied to the exact lot shows which species a bottle contains.

This tab covers molecular identity and assay-level context only. Veracue provides no dosing, administration or usage guidance of any kind.

## Quality & Purity Standards

### Confirming Identity by Mass Spectrometry

Peptides of this size are commonly read by electrospray or MALDI mass spectrometry. The calculated monoisotopic ions below are the numbers to look for in a spectrum. They are computed from the formula C51H84N16O21 (monoisotopic mass 1256.5997 Da) and are reference figures, not Veracue lot results.

Ion: Calculated m/z

[M+H]+: 1257.607
[M+2H]2+: 629.307
[M+Na]+: 1279.589

The average mass of 1257.3 g/mol is the figure for weighing and molar calculations, while the monoisotopic figure is what a high-resolution instrument resolves. Counterions such as acetate or TFA are not covalently bound, so they usually drop out of the spectrum and appear instead as a lower net peptide content.

### Mass Offsets That Point to a Different Species

Shift from 1256.5997 Da (monoisotopic): Possible reading

+18.011 Da: Open N-terminal glutamate in place of the pyroglutamate ring
+17.027 Da: Open N-terminal glutamine in place of the ring
+0.984 Da: Deamidation of the Gln or Asn residue
-0.984 Da: C-terminal amide in place of the free acid

These offsets come from arithmetic on the structure and are a guide to reading a spectrum. A measured result from the lot is what establishes which species, if any, is present.

### What HPLC Adds, and What It Cannot

Reverse-phase HPLC reports chromatographic purity as a peak-area fraction under one set of conditions. The sequence is polar, with only two leucines and one alanine among eleven residues and charged glutamates and an arginine, so related species can elute close together. Ask for the column, gradient and detection wavelength alongside the percentage.

A clean trace shows that few species were detected. It does not by itself show that the main peak is ARA-290, which is why a purity figure should always sit next to a mass result.

### Certificate Checklist for an ARA-290 Lot

- A lot number that matches the label on the bottle received.
- The stated form: free peptide, acetate salt or TFA salt.
- An identity result that gives both calculated and observed mass, with the method named.
- A purity value with its method and conditions.
- The testing laboratory and the test date.

No lot figures are published on the product listing, since results belong to individual lots. The certificate page explains how to request documents for a specific lot, and the contact page handles requests for a bottle with no record listed.

### Reference Identity Versus a Bottle in Hand

CAS 1208243-50-8, PubChem CID 91810664 and UNII 9W5677JKDA all point at the molecule in general. What ties a particular bottle to that molecule is its lot number plus a mass or sequence result from the same lot. For spray-dispensed material, keep the lot number, the certificate and the packaging details (10 mg size, 45 sprays per bottle) together in one record.

## Compliance Notice

### Research Use Only

ARA-290 Spray is sold for laboratory and analytical work by qualified researchers. It is not a drug, dietary supplement, cosmetic or food, and it is not for human or veterinary use, ingestion, injection or any other form of administration. Veracue provides no dosing, administration or usage guidance of any kind. The Medical Disclaimer and the Terms and Conditions set out the sitewide policies, and the buyer is responsible for lawful use within an appropriate research setting.

Nothing in this listing is a statement about safety, efficacy or suitability for any use.

## Questions and answers

### How many residues does ARA-290 have, and in what order?

Eleven: pGlu-Glu-Gln-Leu-Glu-Arg-Ala-Leu-Asn-Ser-Ser, written pGlu-EQLERALNSS in one-letter notation. PubChem records the same chain as XEQLERALNSS, with X marking the N-terminal pyroglutamate.

### Which names refer to the same peptide as ARA-290?

Cibinetide, ARA290 and pHBSP (pyroglutamate helix B surface peptide) all describe it, and the shared identifiers are CAS 1208243-50-8 and PubChem CID 91810664. When a listing uses any of these names, check the sequence and formula rather than the name alone.

### What formula and mass does ARA-290 have?

The free peptide is C51H84N16O21, with an average mass of 1257.3 g/mol and a monoisotopic mass of 1256.5997 Da. A salt form weighs more per mole, so the form named on the lot documentation matters for any molar calculation.

### Which ions should I look for when running ARA-290 on a mass spectrometer?

The calculated monoisotopic [M+H]+ is 1257.607, [M+2H]2+ is 629.307 and [M+Na]+ is 1279.589. These are reference figures, and observed values on a certificate belong to that lot.

### How many sprays are in each ARA-290 Spray bottle?

There are 45 sprays per bottle, and the only size offered is 10 mg.

### How large is ARA-290 next to erythropoietin?

ARA-290 has 11 residues, while EPO is a glycosylated protein of 165 amino acids, about fifteen times longer. The peptide is modeled on the surface of EPO helix B, and the link between them is structural origin only.

### What does the N-terminal pyroglutamate change for identity checks?

It is a ring-closed cap, so the chain has no free N-terminal amine. An open-chain glutamate in its place would read about 18.01 Da higher, which is a clear offset on a mass spectrum.

### How can ARA-290 be told apart from BPC-157 by mass?

ARA-290 averages about 1257.3 g/mol and BPC-157 about 1419.5 g/mol, a gap of roughly 162 Da. They also differ in length (11 versus 15 residues) and in sequence, so a mass spectrum or sequence result separates them cleanly.

### Is the receptor pairing linked to ARA-290 an established fact?

No. The innate repair receptor, proposed as EPOR paired with the beta-common receptor (CD131), is a research model, and binding experiments on the isolated extracellular domains did not detect a direct association. It should be described as proposed.

### Why could an observed mass differ from the reference value?

Electrospray spectra show multiply charged ions and adducts such as sodium, so a raw m/z must be compared with the matching calculated ion. Salt form and modified species, such as a deamidated or uncyclized chain, can shift the result as well.

### Is ARA-290 supplied as a free peptide or as a salt?

PubChem lists acetate and TFA salt forms alongside the free peptide, and the form in a given bottle is a lot-level fact. Request the certificate for the lot, which should state the form.

### Does a purity figure alone confirm ARA-290?

No. A purity percentage describes chromatographic peak area, while identity comes from a mass or sequence result, so both should appear on the same certificate and carry the lot number printed on the bottle.

### What does "non-erythropoietic" tell me about ARA-290?

It names one reported property, the absence of meaningful stimulation of red-cell production in the assays where it was examined. It is a narrow descriptor and not a general statement about the peptide.

### Does Veracue supply usage instructions for ARA-290 Spray?

No. Veracue provides no dosing, administration or usage guidance of any kind, and ARA-290 Spray is sold for laboratory research use only.

More from Veracue Labs: https://veracuelabs.com/llms.txt