Tissue-Protective Peptide · Cibinetide

ARA-290 (Cibinetide): Erythropoietin-Derived Tissue-Protective Peptide

A UK-focused, evidence-based comparison of ARA-290 (Cibinetide) and Dihexa — mechanism, benefits, dosing, side effects, legal status, and stacking.

ARA-290, with international non-proprietary name cibinetide, is an 11-amino-acid synthetic peptide derived from the helix B region of erythropoietin (EPO). It was engineered by Araim Pharmaceuticals to retain the tissue-protective, anti-inflammatory, and nerve-regenerative effects of EPO while eliminating EPO's erythropoietic (red-blood-cell-stimulating) activity — and therefore eliminating EPO's thrombotic and cardiovascular risks. The compound activates the innate repair receptor (a heteromer of EPOR and CD131), a receptor distinct from the classical EPO homodimeric receptor. Cibinetide has been studied in small-fibre neuropathy, sarcoidosis-related neuropathy, diabetic neuropathy, and ischaemia-reperfusion injury, with several Phase 2 trials completed in Europe.

What is ARA-290 (Cibinetide)?

ARA-290 is a synthetic 11-amino-acid peptide engineered from the helix B region of EPO. The "innate repair receptor" it targets is a heterodimer of the classical EPO receptor (EPOR) plus the common β-subunit CD131, expressed on immune cells, endothelial cells, neurons, and tissues responding to injury. By targeting only this heterodimer and not the classical EPOR homodimer, cibinetide produces tissue-protective and anti-inflammatory effects without raising haematocrit. It is the most clinically advanced compound on this list after Cerebrolysin and modafinil, with completed Phase 2 trials and ongoing development by Araim and partners. The compound has been the subject of approximately 40-60 published papers including clinical trial results in small-fibre neuropathy and related conditions.

Chemistry: Quintet of amino acids (proprietary) · short EPO B-helix fragment · MW ~1257 g/mol
Origin: Araim Pharmaceuticals (USA), developed late 2000s
Primary route: Subcutaneous injection
Pharmacokinetics: Plasma half-life under one hour, but functional tissue-protective and anti-inflammatory effects persist days after a dose.
Class: EPO B-helix fragment · Tissue-protective receptor agonist

Mechanism of Action

ARA-290 binds the innate repair receptor (IRR), an EPOR/CD131 heterodimer expressed on a wide range of injury-responding cells. Downstream effects include: activation of the JAK2/STAT3/STAT5 pathway producing anti-apoptotic signalling in stressed cells; reduction of NF-κB-driven inflammation; promotion of nerve regeneration particularly in small unmyelinated fibres (relevant for small-fibre neuropathy); protection of vascular endothelium from ischaemia-reperfusion injury; and modulation of macrophage polarisation toward an M2 anti-inflammatory phenotype. Critically, ARA-290 does not activate the EPOR homodimer on erythroid progenitors, so it does not raise haematocrit and does not carry EPO's thrombotic risk.

Proposed Benefits

The strongest clinical signals are: reduction of neuropathic pain in sarcoidosis-related small-fibre neuropathy (Phase 2 RCT, Heij et al. 2012, 2017); improved corneal nerve fibre density in patients with sarcoidosis or diabetes-related small-fibre neuropathy; reduction of HbA1c and improvement of metabolic markers in Type 2 diabetes (Brines et al. 2014 Phase 2); reduction of post-cardiac-surgery acute kidney injury markers in early trials. Anecdotal nootropic-adjacent use focuses on: nerve healing after injury, post-chemotherapy peripheral neuropathy, post-viral neuropathy, and a small literature on cognitive recovery in post-concussion syndrome via the anti-inflammatory mechanism. ARA-290 is not a classical cognitive enhancer — its place in a cognitive context is neuroprotective and anti-inflammatory rather than directly nootropic.

Evidence Base

The clinical evidence base is the second strongest in this list (after Cerebrolysin). Key references: Brines et al. 2008 (Molecular Medicine, characterisation of the innate repair receptor); Heij et al. 2012 (small-fibre neuropathy in sarcoidosis); Brines et al. 2014 (Phase 2 in Type 2 diabetes); Heij et al. 2017 (longer-term follow-up); Schmidt et al. 2019 (chronic kidney disease). Phase 2 trials have generally shown positive signals on neuropathic pain and small-fibre nerve density; Phase 3 development has been slower than the science would suggest, reportedly due to financing and partnership issues at Araim. The mechanism is well characterised, the receptor is well defined, and the safety profile from human trials is good.

Dosage & Administration

No medically approved dose exists. In published Phase 2 trials cibinetide has been dosed at 1-4 mg subcutaneously, daily or every other day, for 28 days. Community protocols mirror this approach, typically using 2 mg subcutaneously every other day for 4 weeks followed by a maintenance phase of 2 mg twice weekly or a wash-out. The compound is well-tolerated at these doses in trial subjects. Reconstitute lyophilised powder with bacteriostatic water and refrigerate; use within 14-21 days. Subcutaneous injection in the abdomen is standard. Oral, sublingual, and intranasal routes are not viable for systemic effect.

This is a community-reported protocol summary, not a medical recommendation. There is no established human dose. Consult a qualified healthcare professional before using any research compound.

Side Effects & Risks

ARA-290 has the best safety profile of any peptide on this list with clinical trial data — Phase 2 trials report no significant differences in adverse events versus placebo, no haematocrit changes (the safety win versus parent EPO), no thrombotic events, no major laboratory abnormalities. Reported acute effects: occasional injection site reactions, very rare flushing or transient mild headache. The absence of erythropoietic effect is the central safety feature — full-length EPO has caused thromboembolic events when given to neuropathy patients, which is why the engineered cibinetide peptide exists. Contraindications: pregnancy/breastfeeding (no safety data), known peptide hypersensitivity, possibly active malignancy (the IRR/STAT3 pathway has potential tumour relevance though no clinical signal has emerged).

UK Legal Status

UK: not a controlled substance, not licensed by MHRA, not scheduled under the Psychoactive Substances Act. Legal as a research chemical for laboratory use. The compound is an investigational medicinal product under active clinical development, and personal-use import sits in the same grey area as other clinical-stage peptides. WADA: ARA-290 is an EPO-derived compound and ALL erythropoiesis-stimulating agents and their analogues are banned by WADA — even though ARA-290 specifically does not stimulate erythropoiesis, athletes should consult anti-doping guidance before any use given the EPO-related origin. US: investigational; not FDA-approved for any indication.

ARA-290 (Cibinetide) vs Dihexa

ARA-290 and Dihexa share some pro-regenerative and anti-inflammatory positioning but address different goals. ARA-290 is a tissue-protective peptide with a defined receptor (innate repair receptor), strongest evidence in small-fibre neuropathy and ischaemia-reperfusion contexts, and an anti-inflammatory plus nerve-regenerative profile. Dihexa is a CNS-targeted synaptogenic peptide acting via HGF/c-Met to drive structural cognitive plasticity. They occupy complementary niches: ARA-290 for systemic / peripheral nerve and inflammation contexts, Dihexa for CNS structural plasticity. ARA-290 has the better-defined receptor pharmacology and human clinical trial data; Dihexa has the more targeted CNS-cognitive mechanism. For users with peripheral neuropathy alongside cognitive concerns, the combination has a defensible rationale.

Stacking with Dihexa

ARA-290 is rarely stacked aggressively with other peptides because its tissue-protective indication is typically specific (small-fibre neuropathy, post-surgical recovery, diabetic neuropathy) rather than general enhancement. In Dihexa-context use, ARA-290 + Dihexa would be a reasonable pairing for post-stroke, post-TBI, or post-chemotherapy recovery where both peripheral nerve and CNS support are needed. ARA-290 may also have a role alongside Cerebrolysin in major neurological injury recovery. No published interaction data exists. The compound's clean safety profile makes combination reasonable from a safety standpoint, but the specificity of the cibinetide indication means most cognitive-enhancement-focused users will not need it.

Frequently Asked Questions

No. ARA-290 is engineered from the helix B region of EPO to retain EPO's tissue-protective effects while eliminating its erythropoietic (red blood cell stimulating) activity. It binds a different receptor (innate repair receptor) than the classical EPO receptor.

No — this is the engineering point of the compound. Phase 2 trial data confirms no measurable haematocrit change at therapeutic doses.

All erythropoiesis-stimulating agents and their analogues are on the WADA Prohibited List. ARA-290 does not stimulate erythropoiesis, but athletes should consult anti-doping guidance before any use given the EPO-related origin.

Not directly. Its primary clinical signal is in small-fibre neuropathy, post-surgical nerve protection, and metabolic / inflammatory contexts. Cognitive benefit would be secondary, via the anti-inflammatory mechanism.

No. Subcutaneous injection is required.

Cibinetide is the international non-proprietary (generic) name assigned by the WHO INN programme. ARA-290 is the original development code from Araim Pharmaceuticals.

The Bottom Line

ARA-290 (cibinetide) is the best-characterised tissue-protective and small-fibre neuropathy peptide in clinical development, with completed Phase 2 trial data and a defined receptor mechanism (innate repair receptor). Its EPO-derivative origin gives it a clear regulatory positioning concern for athletes but offers no actual thrombotic or erythropoietic risk. As a complement to Dihexa in neuropathy or post-injury recovery contexts the combination is mechanistically reasonable; for pure cognitive enhancement it is not the primary tool.