ARA-290: What It Is, Where to Get It Prescribed, and What It Costs

ARA-290 is a short peptide — eleven amino acids — whose sequence was lifted from the surface of one helix of erythropoietin, the hormone the kidney releases to tell bone marrow to make red blood cells. It was not found in nature. It was engineered, and the 2008 paper in the Proceedings of the National Academy of Sciences that introduced it is titled "Nonerythropoietic, tissue-protective peptides derived from the tertiary structure of erythropoietin." That title is the whole idea: keep the part of erythropoietin that appears to protect tissue, leave behind the part that raises red cell counts.

Erythropoietin itself had been studied for nerve, heart and kidney protection and kept hitting the same wall: at the doses needed, it thickens the blood and raises clotting risk. ARA-290 was built to avoid that. It does not bind the erythropoietin receptor pair that drives red cell production, so it does not raise haemoglobin.

ARA-290 is the developer's code name — the compound came out of Araim Pharmaceuticals, and the same group (Brines, Cerami, Dahan and colleagues) authored most of the human work. Its international non-proprietary name is cibinetide, which is what the later papers and the FDA's own lists use. Older literature calls it "helix B surface peptide." All are the same molecule.

It is not erythropoietin, and it does not do what erythropoietin does to blood counts. It is not a conventional painkiller: it does not act on sodium channels or opioid receptors, and the trials measured it over weeks, not hours. It is not a hormone or a growth hormone secretagogue. And it is not an approved drug for anything: it went through phase 2 trials and has not been approved by the FDA or any other regulator.

Erythropoietin signals through two receptor assemblies. The classical one is a pair of erythropoietin receptors, and it drives red cell production. The second pairs one erythropoietin receptor with the β-common receptor (CD131); the research group named it the "innate repair receptor" and describes it as switched on in injured or inflamed tissue rather than healthy tissue. ARA-290 is described as engaging only this second assembly. The clearest evidence is a 2011 study in Anesthesiology: in rats and normal mice with a nerve injury, ARA-290 reduced pain-related behaviour for weeks, but in mice bred without the β-common receptor it did nothing.

The proposed downstream effect is anti-inflammatory. A 2014 paper in Molecular Pain reported that five doses in the first ten days after a nerve injury in rats reduced pain-related behaviour for up to twenty weeks and suppressed activation of spinal cord microglia — the immune cells thought to sustain neuropathic pain once it starts. The 2016 review in Pain Reports frames this as reprogramming "a proinflammatory, tissue-damaging milieu into one of healing and tissue repair." That is the authors' language: a hypothesis with animal support, not a demonstrated human mechanism.

Small nerve fibres carry pain and temperature and run the autonomic system; they are what is lost in small-fibre neuropathy. The human trials used corneal confocal microscopy — a non-invasive eye scan that counts nerve fibres in the cornea — as a surrogate for small fibre density elsewhere. Across the sarcoidosis and diabetes trials below, corneal nerve fibre density or area increased in treated patients, and the 2017 phase 2b trial also reported more regenerating fibres in skin biopsies at the effective dose. The 2016 review notes that in the earlier trial regrowth was seen in the cornea but not the epidermis, so this is a real but partial signal.

This was not the original target. In a 2015 phase 2 study in Molecular Medicine, people with type 2 diabetes and painful neuropathy who took ARA-290 for 28 days showed improved haemoglobin A1c and lipid profiles compared with placebo. Animal work in diabetic rats (Molecular Medicine, 2016) reported improved insulin release and glucose tolerance. The mechanism in humans is not established, and it has not been pursued to a larger trial.

The first human trial (Molecular Medicine, 2012) enrolled 22 people with sarcoidosis and symptoms of small-fibre neuropathy: 12 received ARA-290 by intravenous infusion three times a week for four weeks, 10 received placebo. No safety concerns were raised. At week four the treated group improved more than placebo on the Small Fiber Neuropathy Screening List, a symptom questionnaire, and improved from baseline on the pain and physical-functioning parts of the SF-36. The part most summaries leave out: the Brief Pain Inventory pain score and the fatigue score improved equally in both groups, and depressive symptoms did not change. The pilot showed a symptom-questionnaire signal, not a pain-intensity signal separated from placebo.

The follow-up (Molecular Medicine, 2013) moved to 28 days of once-daily subcutaneous injection — the route Pepti's product uses — in a blinded, placebo-controlled design in patients with documented small nerve fibre loss. Treated patients reported improved neuropathic symptoms, and the trial added objective measures: corneal nerve fibre density increased, skin temperature sensitivity changed, and six-minute walk distance increased. This is the trial that moved the authors' framing from "symptom relief" to "possible disease modification."

The largest trial (Investigative Ophthalmology & Visual Science, 2017) randomised 64 people with sarcoidosis-associated small nerve fibre loss and neuropathic pain to placebo or one of three daily doses for 28 days. The primary endpoint was change in corneal nerve fibre area. Only the middle dose beat placebo on it; the low and high doses did not reach significance. The middle dose also increased regenerating fibres in skin biopsy. Pain improved in every group including placebo, and the placebo-corrected reduction in pain intensity at the middle dose — described as clinically meaningful in those with moderate-to-severe pain — was not statistically significant. The strongest evidence is for an objective nerve-fibre change; the evidence for pain relief beyond placebo is weaker than the marketing around this peptide usually implies.

The 2015 phase 2 study in Molecular Medicine gave people with type 2 diabetes and painful neuropathy 28 days of daily subcutaneous ARA-290 or placebo, then followed them a further month. No safety issues were identified. Neuropathic symptoms on the PainDetect questionnaire improved significantly in the treated group. Corneal nerve fibre density increased in the subset who started with clearly reduced density and did not change on placebo. The HbA1c and lipid findings came from the same study. It has not been replicated in a larger population.

There are randomised, double-blind, placebo-controlled phase 2 trials of ARA-290 in humans, in sarcoidosis-associated small-fibre neuropathy and in type 2 diabetes with painful neuropathy. That is more than most compounded peptides can say. The trials were small (22 to 64 people), short (four weeks of treatment), run by the developer, and used surrogate endpoints — questionnaires and corneal nerve counts — rather than hard outcomes. No phase 3 trial has been completed and no regulator has approved it.

Two smaller studies round out the picture. A 2020 open-label study (Journal of Clinical Medicine) gave nine patients with diabetic macular oedema twelve weeks of daily cibinetide and found no improvement in visual acuity or retinal thickness, though the course was safe and no antibodies to the peptide were detected. A single-dose study in 36 healthy volunteers (European Neuropsychopharmacology, 2015) found no effect on mood. Neither is a success, and an honest page says so.

The fair summary: a consistent signal on small nerve fibre regrowth and neuropathy symptom questionnaires in two specific patient populations, a clean safety record over four-week courses, and no proof of durable pain relief or of benefit in any other condition.

• It does not establish that ARA-290 reduces pain intensity more than placebo. The symptom questionnaires separated from placebo; the pain-intensity scores did not.
• It does not establish benefit in neuropathy from other causes — chemotherapy, alcohol, idiopathic, injury — because those populations were not studied.
• It does not establish what happens beyond four weeks of treatment, or with repeated courses.
• It does not establish a benefit for general recovery, injury or performance. Those uses rest on animal work and mechanism.
• It does not establish efficacy for any condition as an FDA-approved treatment. It is not approved for anything.

The trials measured nothing before week four, so there is no human data on what the first days feel like. Prescribers describe the early period as uneventful for most people. Nerve fibre regrowth, if it happens, is slow, and there is no reason to expect a change in burning or tingling within days.

This is the only window with human trial data. At day 28 the sarcoidosis and diabetes trials reported changes in symptom questionnaires and corneal nerve fibre counts. A vial is sized to cover this window — twenty weekday doses over about four weeks — which lines up with the treatment length that has actually been studied.

No trial dosed for longer than four weeks. The diabetes study followed people for a month afterwards, during which the metabolic improvements persisted. Whether continued dosing adds anything is unknown. This is a conversation to have with your physician before starting, and again at the first refill.

It is not an analgesic. If what you need is something that takes the edge off tonight, this is the wrong tool and your physician will say so. Pain-intensity scores in the trials moved in the placebo groups almost as much as in the treated groups.

The directions are written in millilitres and in insulin-syringe units because that is what you can actually read off the barrel. 0.25 mL is 25 units on a U-100 syringe. You are not calculating anything — the number is printed on your medication.

Subcutaneous means into the fat layer, not the muscle. Abdomen and thigh are the usual sites, rotated so the same spot is not used repeatedly. The 2013 sarcoidosis trial and the 2015 diabetes trial both used daily subcutaneous self-injection, so this route is the one with human data behind it. There is no logic to injecting near a painful area: the mechanism described is systemic, through a receptor expressed wherever tissue is inflamed.

The reviewed directions are once daily on weekdays, which is 20 doses per vial and about four weeks — the same treatment length the human trials used. The weekday schedule is a prescribing pattern, not a trial design: the trials dosed daily, at amounts set by the sponsor that are not the same as a compounded prescription's directions. Your physician sets yours. One vial per fill, always — not a stockpile.

Refrigerated, and it ships that way in insulated packaging with ice packs. The peptide is broken down quickly by enzymes in blood, which is part of why it is injected rather than swallowed, but in the vial it is stable when kept cold. Beyond-use dating runs from first puncture and is on the label.