ARA-290

What is ARA-290?

ARA-290 is the development code for cibinetide, a synthetic peptide designed from the aqueous-facing surface of helix B of erythropoietin (EPO). It is not a shortened vial of EPO and should not be expected to reproduce EPO's red-blood-cell effect.

The original design paper identified a short surface sequence that retained tissue-protective activity in experimental injury models without erythropoietic activity. The proposed target is the innate repair receptor, commonly described as a complex involving an EPO-receptor subunit and the beta-common receptor CD131. ([Brines et al., PNAS, 2008](https://pubmed.ncbi.nlm.nih.gov/18676614/))

Why the N-terminal pyroglutamate matters

The first glutamine cyclizes to pyroglutamate, which is why the intact sequence is written pGlu-EQLERALNSS, not simply QEQLERALNSS. A label that reports a different sequence, an unmodified N-terminus, or an unspecified “EPO fragment” does not by itself establish cibinetide identity.

Research-vial identity and quality checks

Confirm exact cibinetide identity before comparing with trial protocols. A high HPLC purity number alone cannot prove identity, absolute content, sterility, endotoxin status, or formulation stability.

Current research status

Cibinetide reached Phase 2 development and received orphan-drug designations for sarcoidosis-related neuropathic indications, but designation is not marketing authorization. No Phase 3 confirmatory program or US prescribing information establishes a clinical dose.

FDA's May 2026 list of bulk substances nominated for 503A compounding places cibinetide in Category 3, nominated without adequate support. That classification concerns the compounding-list process; it is not a judgment that the published Phase 2 papers never occurred. It does mean that a research-vial product should not be treated as equivalent to the sterile, characterized investigational product used in those trials. ([FDA 503A bulk-substance categories](https://www.fda.gov/media/94155/download))

No established prescribing dose. Research-vial cibinetide is not equivalent to the sterile investigational product used in Phase 2 trials.

Dosage used in human clinical trials

The human literature includes pharmacokinetic work, randomized controlled studies, dose ranging, and a 12-week exposure. It remains a small evidence base concentrated in specific disease populations.

What the dose-ranging trial actually showed

DOSARA is the most useful study for dose selection because it compared placebo with 1, 4, and 8 mg daily under the same 28-day design. Placebo-corrected mean change in corneal nerve-fiber area (CNFA) at day 28:

Regenerating GAP-43-positive skin fibers also increased in the 4 mg group. Pain improved in every group; the placebo-corrected pain reduction in the moderate-to-severe subgroup favored 4 mg but did not reach conventional statistical significance (P=0.157). These results support 4 mg as the best-studied signal-generating dose, not as a universally established therapeutic dose. ([Culver et al., 2017](https://pubmed.ncbi.nlm.nih.gov/28475703/))

Complete trial-anchored 28-day ARA-290 research protocol

This protocol reproduces the central 4 mg SC once-daily for 28 days human-research schedule and adds a prospective measurement and safety framework. The dosing schedule, thigh administration, rotating sites, and day-14/day-28 laboratory monitoring are taken from human study methods.

The human trials did not use a 1 mg-to-2 mg-to-4 mg titration, split the daily 4 mg into multiple doses, or taper at the end. Those modifications should be described as new experimental variables rather than presented as the original protocol.

ARA-290 research dosage

The table below documents commonly reported protocols from human trials and community conventions. Community links document reported practice — they do not establish clinical validation.

Human research directly supports that investigators have administered 1–8 mg subcutaneously once daily for 28 days, 4 mg daily for 12 weeks, and 2 mg intravenously three times weekly for four weeks. Of these, 4 mg SC daily for 28 days has the strongest combination of replication, objective outcomes, and dose-ranging support.

No controlled study identified here establishes a need to titrate, split the dose, inject at bedtime, cycle five days on and two days off, repeat courses indefinitely, inject near a painful nerve, or combine ARA-290 with BPC-157, TB-500, GHK-Cu, growth hormone secretagogues, ketamine, or EPO.

Reported ARA-290 dosage range

Clinical versus anecdotal dosing

The key discrepancy is not simply the milligram amount. Community protocols often change frequency, formulation, duration, monitoring, and product quality at the same time, making them poor replications of the clinical research.

Why 4 mg daily appears repeatedly

After a 4 mg subcutaneous dose in healthy volunteers, the published diabetes study cited a peak plasma concentration of about 3 ng/mL (2.4 nmol/L) and a terminal half-life of about 20 minutes. The early IV half-life was about two minutes. Researchers proposed that a brief receptor signal could initiate longer intracellular repair responses, so continuous blood exposure was not the experimental goal.

The 4 mg dose then produced the clearest primary-endpoint signal in DOSARA, whereas 1 mg appeared insufficient and 8 mg did not improve the endpoint further. That pattern may reflect a non-linear biological response, trial variability, or both. It does not justify extrapolating beyond 8 mg.

ARA-290 reconstitution and concentration math

The clinical studies used manufactured sterile solutions. They did not establish that a retail lyophilized vial mixed with bacteriostatic water is chemically or microbiologically equivalent. The calculations below answer concentration questions only.

Concentration (mg/mL) = vial amount (mg) ÷ final volume (mL) · Draw volume (mL) = target amount (mg) ÷ concentration (mg/mL) · U-100 units = draw volume (mL) × 100. One U-100 unit is a volume of 0.01 mL — not a universal peptide dose.

The diabetes paper reports a study vehicle containing 20 mmol/L sodium phosphate buffer at pH 6.5, 1% sucrose, and 4% D-mannitol. That describes the investigational formulation — not a simplified reconstitution recipe.

Preclinical ARA-290 dosage

Animal / preclinical research only. These doses answer model-specific scientific questions and should not be converted directly into human protocols.

The broad range reflects different species, models, routes, and endpoints — not a menu of interchangeable human doses.

How ARA-290 may work

1. Innate repair receptor signaling — The proposed innate repair receptor contains an EPO-receptor component and CD131, induced during injury or metabolic stress. ARA-290 was designed to favor tissue-protective pathway rather than classical erythropoietic receptor.
2. Anti-inflammatory and cell-survival pathways — Preclinical studies connect receptor engagement with JAK2/STAT, PI3K/Akt, suppression of inflammatory signaling, reduced apoptosis, and tissue-repair responses. Mechanistic findings — not automatic evidence every inflammatory condition improves in humans.
3. Nerve-fiber repair rather than immediate analgesia — Strongest human evidence measured corneal nerve-fiber area and GAP-43-positive regenerating skin fibers. Surrogate endpoints — not proof of complete functional nerve repair.

What results have actually been shown?

Expected timeline in research

Online promises of guaranteed onset within days or permanent nerve repair after one course go beyond the published studies.

ARA-290 dosage evidence ladder

ARA-290 dosing is better documented than dosing for many research peptides, but it is not clinically established. The clearest research anchor is 4 mg subcutaneously once daily for 28 days, followed by observation.

Safety and adverse effects

Across small trials, investigators did not identify a consistent erythropoietic effect or a clear laboratory toxicity pattern at the studied doses. That is reassuring, but the largest trial randomized only 64 participants and repeated long-term courses have not been adequately studied.

Storage and stability

No US prescribing label provides a universal storage condition or beyond-use period for research ARA-290. The clinical studies used professionally manufactured sterile vials with defined vehicle and study handling.

Generic advice that every mixed peptide lasts 28 days refrigerated is not formulation-specific stability evidence. Cloudiness, discoloration, visible particles, or temperature excursion should invalidate the material.

Comparisons

Neuropathic symptoms can reflect diabetes, autoimmune disease, vitamin deficiency, medication toxicity, nerve compression, infection, vascular disease, or central pathology — the cause changes the appropriate standard evaluation.

Bottom line

ARA-290 is the defined 11-amino-acid peptide cibinetide, not a generic EPO fragment. Its most defensible research schedule is 4 mg subcutaneously once daily for 28 consecutive days, followed by an observation period. That regimen was used in multiple human studies and had the strongest signal in the only 1-versus-4-versus-8 mg dose-ranging trial.

The evidence is promising rather than conclusive. Objective corneal and skin nerve markers improved at 4 mg, but symptom results were less consistent, the largest study included only 64 participants, and the longest published course had eight completers.

Preserve the human-trial protocol, reconstitution math, negative and positive outcomes, and the real adverse-event record — without converting an investigational dose into a universal treatment claim.

Frequently asked questions

References

• Brines M, Patel NSA, Villa P, et al.

  Nonerythropoietic, tissue-protective peptides derived from the tertiary structure of erythropoietin

  Proc Natl Acad Sci USA. 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

  Mol Med. 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

  Mol Med. 2013;19:334–345.

• 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

  Mol Med. 2015;20:658–666.

• Cerit H, Veer IM, Dahan A, et al.

  Testing the antidepressant properties of the peptide ARA290 in a human neuropsychological model of drug action

  Eur Neuropsychopharmacol. 2015;25(12):2289–2299.

• 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

  Invest Ophthalmol Vis Sci. 2017;58(6):BIO52–BIO60.

• Lois N, Gardner E, McFarland M, et al.

  A Phase 2 clinical trial on the use of cibinetide for the treatment of diabetic macular edema

  J Clin Med. 2020;9(7):2225.

• Swartjes M, Morariu A, Niesters M, et al.

  ARA290, a peptide derived from the tertiary structure of erythropoietin, produces long-term relief of neuropathic pain: an experimental study in rats and beta-common receptor knockout mice

  Anesthesiology. 2011;115(5):1084–1092.

• European Union Clinical Trials Register.

  EudraCT 2013-003016-45: DOSARA trial results

  Clinical trial registry results.

• National Center for Biotechnology Information.

  Cibinetide, PubChem CID 91810664

  PubChem compound record.

• US Food and Drug Administration.

  Bulk drug substances nominated for use in compounding under section 503A

  Updated May 14, 2026.