ARA-290 is a synthetic 11-amino-acid peptide with a molecular weight of about 1,257 daltons. It was engineered from the helix-B region of erythropoietin (EPO), the hormone that drives red blood cell production. In clinical development it is called cibinetide, and you'll also see it written as PHBSP, pHBSP, or ARA290.
The point of the design was to keep one part of EPO's biology and drop another. Full erythropoietin activates the classical EPO receptor and raises hematocrit, which carries thrombotic risk. ARA-290 was built to skip that pathway and instead bind selectively to what its developers call the innate repair receptor (IRR), described as a heterodimeric complex of the EPO receptor subunit and the beta-common receptor (CD131). According to the published research, signaling through this complex is associated with anti-inflammatory and anti-apoptotic (cell-protective) effects, without stimulating erythropoiesis. The peptide was developed by Araim Pharmaceuticals.
What the research shows
Unlike most peptides marketed to the research-chemical crowd, ARA-290 has actually been through human trials, though small ones.
- Sarcoidosis-associated small fiber neuropathy. A randomized, double-blind, placebo-controlled pilot study published in Molecular Medicine enrolled 22 patients and gave 2 mg of ARA 290 (or placebo) intravenously three times weekly for four weeks. The authors reported improvement in neuropathic symptoms (Heij et al., 2012, Molecular Medicine). A later study reported that cibinetide increased corneal nerve fiber density, a biomarker of small-fiber nerve health, in sarcoidosis patients (IOVS / ARVO Journals).
- Type 2 diabetes with neuropathy. A Phase 2 double-blind, placebo-controlled trial randomized 48 patients (24 per arm) to self-injected subcutaneous ARA 290 (4 mg) or placebo daily for 28 days, with follow-up to day 56. The treatment group showed a modest fall in HbA1c versus a rise on placebo, improvement on the PainDetect neuropathic symptom score, and an increase in corneal nerve fiber density among affected subjects (Brines et al., 2015, Molecular Medicine, PMC4365069).
- Registered trials. A Phase 2 study of ARA 290 in sarcoidosis (corneal nerve fiber density and neuropathic symptoms) is listed on ClinicalTrials.gov as NCT02039687.
These are early-phase, small-sample results. They point to a signal in nerve-related endpoints, not to proven efficacy. No large confirmatory trials have established ARA-290 as an effective treatment for any condition.
Regulatory and quality notes
ARA-290 / cibinetide is not approved by the FDA (or other major regulators) for any therapeutic use. It has held orphan-drug designation tied to sarcoidosis-associated small fiber neuropathy, but designation is not approval. Anything sold under this name online is sold for laboratory research only and is not intended for human consumption.
Because it isn't a regulated pharmaceutical, material sold as "ARA-290" varies in quality between sellers. There is no pharmacy-grade supply chain behind it. If you are evaluating a vendor, the things worth checking are independent third-party analysis: a recent certificate of analysis (COA) confirming identity and purity by mass spectrometry and HPLC, and how that lines up with the independent vendor-testing programs peptideone aggregates. A label is not a test result.
Nothing here is medical, dosing, or efficacy advice. It's a summary of what the public record currently documents about this compound.