TL;DR: ARA-290 (Cibinetide, marketed in research circles as Cibinetida in Spanish and Cibinetid in German) is an 11-amino-acid peptide carved out of the tissue-protective “Helix-B” face of erythropoietin (EPO). Unlike EPO itself, it is non-erythropoietic — it does not build red blood cells. Instead it selectively switches on the innate repair receptor (IRR), an EPOR/CD131 heterodimer that governs anti-inflammatory signalling and tissue regeneration. That has made it one of the most-studied “nerve repair peptides” in the small-fibre neuropathy literature, with a headline result: regrowth of corneal nerve fibres in sarcoidosis patients, plus EU and US Orphan Drug Designation for that indication.
What ARA-290 actually is
Erythropoietin is famous for making red blood cells, but researchers noticed decades ago that EPO also protects tissue during injury — and that these two jobs run through different receptors. The red-cell job uses the classic EPO receptor homodimer. The tissue-protective job uses the innate repair receptor, a partnership between the EPO receptor and the beta-common receptor (CD131 / CSF2RB).
ARA-290 is the elegant consequence of that split. Chemists mapped the tissue-protective activity to Helix B on the surface of the EPO molecule and synthesised just that stretch as an 11-amino-acid peptide — the Helix-B surface peptide (HBSP), later named Cibinetide. Because it only engages the IRR and never the erythropoietic receptor, it delivers the “repair” half of EPO’s biology without raising haematocrit. That is the whole point, and it is why the phrase EPO-derived peptide shows up everywhere it is discussed.
Why the IRR matters for neuropathy
Small-fibre neuropathy is damage to the thin, unmyelinated nerves that carry pain and autonomic signals. It underlies a lot of “burning feet,” temperature-sensitivity, and hard-to-treat neuropathic pain — and conventional analgesics mostly mask symptoms rather than repair the fibres.
The research rationale for ARA-290 is different. As an IRR agonist, it is studied for its ability to calm the local inflammatory environment around injured nerves and support the machinery of tissue repair, potentially allowing the small fibres themselves to regrow. That is a mechanistic story about fixing the wire, not just quieting the alarm — which is exactly why “neuropathy peptide” became its nickname.
The sarcoidosis story — the credibility hook
Sarcoidosis is an inflammatory disease that frequently comes with painful small-fibre neuropathy, and it became the flagship indication for ARA-290. In a randomised, double-blind pilot study, sarcoidosis patients with small-fibre neuropathy symptoms received ARA-290 subcutaneously and reported improvements in neuropathic and autonomic symptom scores versus placebo.
The follow-on work is what turned heads: a two-centre, placebo-controlled study reported that 28 days of Cibinetide initiated regrowth of corneal nerve fibres (measured by corneal confocal microscopy) alongside reductions in pain and gains in functional capacity. Nerve regrowth, not just symptom relief, is a high bar — and it is why both the EU and the US granted Orphan Drug Designation for sarcoidosis-associated small-fibre neuropathy. (For the record: as of 2026 ARA-290 is not an approved medicine in any jurisdiction; it remains a research compound.)
Daily SC doses evaluated in the double-blind phase-2b program over a 28-day course. Illustrative of the published literature, not a protocol.
The diabetic and neuropathic-pain angle
Sarcoidosis was the orphan wedge, but the broader interest is metabolic. In a study of people with type-2 diabetes — the single biggest source of peripheral neuropathy worldwide — ARA-290 was reported to improve neuropathic symptom scores and certain metabolic markers over a treatment course. The read across the literature is consistent: wherever small nerves are inflamed and dying, researchers have been curious whether an IRR agonist can shift the environment toward repair. That is the engine behind ongoing interest in ARA-290 as a general-purpose nerve repair peptide rather than a one-disease tool.
Typical research reconstitution
ARA-290 is a lyophilised powder that research protocols reconstitute with bacteriostatic water before subcutaneous handling. A 16 mg vial gives plenty of headroom for the low-single-milligram dose points seen in the literature.
Reconstitution math is where most handling errors creep in, so run your vial size, water volume, and target dose through the peptide dosing calculator rather than eyeballing it. If you want the mechanism from the ground up, the what is ARA-290 primer pairs well with this guide, and the ARA-290 16mg reference page covers the compound specifics.
Frequently Asked Questions
Is ARA-290 the same thing as Cibinetide?
Yes. ARA-290 is the developmental code and Cibinetide is the assigned generic name for the identical 11-amino-acid peptide. You will also see it referenced as Cibinetida in Spanish-language sources and Cibinetid in German ones, and occasionally as the Helix-B surface peptide (HBSP).
Does ARA-290 raise red blood cell counts like EPO?
No — that is its defining feature. It was engineered from EPO’s tissue-protective Helix-B region specifically to activate the innate repair receptor without engaging the classic erythropoietic receptor, so in the research literature it does not increase haematocrit or red-cell mass.
What is the innate repair receptor?
The IRR is a heterodimer of the EPO receptor and the beta-common receptor (CD131 / CSF2RB). It is the channel through which EPO exerts its anti-inflammatory and tissue-repair effects, separate from red-cell production. ARA-290 is a selective IRR agonist.
Why is sarcoidosis mentioned so often with ARA-290?
Sarcoidosis-associated small-fibre neuropathy was the lead research indication, and it is where the strongest data sit — including reported corneal nerve fibre regrowth. That evidence earned ARA-290 Orphan Drug Designation in both the EU and the US, which is the main credibility anchor for the compound.
What doses appear in ARA-290 studies?
Published sarcoidosis work evaluated 1, 4, and 8 mg subcutaneously once daily over 28-day courses. These are literature figures for context, not a recommendation; always model your own numbers with the calculator.
References
- Brines M, Patel NS, Villa P, et al. “Nonerythropoietic, tissue-protective peptides derived from the tertiary structure of erythropoietin.” Proceedings of the National Academy of Sciences (PNAS). 2008;105(31):10925-10930.
- Heij L, Niesters M, Swartjes M, et al. “Safety and efficacy of ARA 290 in sarcoidosis patients with symptoms of small fiber neuropathy: a randomized, double-blind pilot study.” Molecular Medicine. 2012;18:1430-1436.
- Dahan A, Dunne A, Swartjes M, et al. “ARA 290 improves symptoms in patients with sarcoidosis-associated small nerve fiber loss and increases corneal nerve fiber density.” Molecular Medicine. 2013;19:334-345.
- Culver DA, Dahan A, Bajorunas D, et al. “Cibinetide improves corneal nerve fiber abundance in patients with sarcoidosis-associated small nerve fiber loss and neuropathic pain.” Investigative Ophthalmology & Visual Science. 2017;58(6):BIO52-BIO60.
- Brines M, Dunne AN, van Velzen M, et al. “ARA 290, a nonerythropoietic peptide engineered from erythropoietin, improves metabolic control and neuropathic symptoms in patients with type 2 diabetes.” Molecular Medicine. 2015;20:658-666.
- Review of innate-repair-receptor pharmacology and its application to neuropathy (open-access review; PubMed Central, 2017), describing the EPOR/CD131 heterodimer as a therapeutic target.
This article is an educational and research reference only. ARA-290 (Cibinetide) is not an approved medicine, this is not medical advice, and the compound is not for human consumption.