What is the ARA-290 peptide dosage used in studies?

4 mg subcutaneously once daily for 28 days in the two later trials, chosen from a pharmacokinetic comparison against the 2 mg intravenous dose used three times a week in the 22-patient pilot. The phase 2b study tested 1, 4 and 8 mg daily; only 4 mg beat placebo on the primary endpoint and 8 mg was not better. Those are study doses in patients with a specific diagnosis, under supervision, for a fixed 28 days. They are not an approved dose and not a recommendation.

Is ARA-290 FDA approved?

No. Cibinetide has never been approved in any country. On the FDA's 503A bulk substances list updated 14 May 2026 it appears in Category 3 — nominated without adequate support — and it is absent from the agency's safety-risk page. Araim Pharmaceuticals announced orphan drug and fast track designations in 2017; those are development incentives granted before efficacy is established, not approvals, and no phase 3 trial has been published since.

Does ARA-290 raise red blood cells like EPO?

It is specifically engineered not to. ARA-290 is an eleven-amino-acid peptide modelled on helix B of erythropoietin that binds the innate repair receptor — an EPO receptor and β-common receptor heterodimer induced by injury — rather than the EPO receptor homodimer that drives red cell production. Avoiding the haematocrit rise, platelet activation and thrombosis risk of recombinant EPO was the entire design goal. That is the published rationale; it does not make the compound approved or its long-term safety established.

What is ARA-290's half-life?

About two minutes in plasma. The published pharmacology explains the apparent contradiction with once-daily dosing: exposure in the trials was measured as time above an activation threshold of roughly 1.3 ng/mL, and the receptor activation triggers downstream effects that persist far longer than the peptide itself.

How many syringe units is a 4 mg dose from a 10 mg vial?

It depends on the water you added. 10 mg with 2 mL gives 5 mg/mL, so 4 mg is 0.8 mL — 80 units on a U-100 syringe, which is most of a 1 mL barrel. With 1 mL of water it becomes 10 mg/mL and 4 mg is 40 units. Use the calculator above to check your own vial; the arithmetic is the only thing this page can tell you with certainty.

ARA-290 Peptide Dosage Calculator and Study Dose Chart

An eleven-amino-acid peptide engineered from erythropoietin that activates the innate repair receptor without stimulating red cell production. It reached phase 2 in sarcoidosis small-fibre neuropathy, then development stopped.

Written by Kashif Khan, who builds and maintains this site and is not a clinician. Every figure links to its primary source.

Not approved

Not approved; on the 503A list only in Category 3

There is no approved cibinetide product in any country. On the FDA's 503A list updated 14 May 2026, “Cibinetide (ARA-290)” appears in Category 3 — bulk drug substances nominated without adequate support — which means the nomination did not come with enough information for the agency to evaluate it, not that it was assessed and cleared. It is not in Category 1 and not in Category 2, and it does not appear anywhere on the FDA's safety-risk page for bulk substances. Araim Pharmaceuticals announced US orphan drug and fast track designations for neuropathic pain in sarcoidosis, plus orphan designations covering sarcoidosis and pancreatic islet transplantation, in 2017; a designation is an incentive for development, not evidence of efficacy and not an approval. No phase 3 trial has been published.

No approved human dose exists for this compound in any country. The figures below are the doses used in named published studies, reproduced for reference only. Doses given to rats or mice do not convert to a human dose. The FDA has stated that labelling a product “research use only” or “not for human consumption” does not change its legal status when the seller's own marketing shows it is intended for people.

Anti-doping: Not named, but the S2.1.5 class it belongs to is prohibited. ARA-290 is not listed by name on the 2026 WADA Prohibited List. The list's S2.1.5 covers “Innate repair receptor agonists, e.g. asialo EPO; carbamylated EPO (CEPO)”, and S2 states that “the following substances, and other substances with similar chemical structure or similar biological effect(s), are prohibited”. ARA-290 is described in its own literature as an engineered ligand of exactly that receptor, so an athlete should assume it falls inside S2.1.5 as a non-Specified Substance prohibited at all times. This is our reading of the class wording, not a WADA ruling naming the compound.

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ARA-290 in the vial

4 mg is the trial figure, shown for the arithmetic — not a recommendation

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No approved human dose exists for this compound. The dose shown is only a calculator input, not a recommendation or starting point.

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80units(0.8 mL)

Concentration: 5 mg/mL
Water added: 2 mL
Doses in vial: 2

How the concentration is calculated

This divides the peptide by the water you add. The powder occupies a little volume of its own, which is negligible on a typical vial but not on one with a heavy bulking agent. When a product label states a concentration, use the label’s number.

80 units exceeds this syringe's 50-unit capacity. Use less water, or a larger syringe.

Key facts

Molecular weight: 1,257.3 DaPubChem CID 91810664, C51H84N16O21. Eleven amino acids, modelled on helix B of erythropoietin.
Half-life: About 2 minutes in plasma; the biological effects outlast the exposure by far
Also sold as: cibinetide, pyroglutamate helix B surface peptide, pHBSP

Doses used in published studies

These are reproduced for reference. They are not recommendations, and an animal dose in mg/kg does not convert to a human dose.

humanintravenous, three times a week for 4 weeks

2 mg per administration

Heij et al., Molecular Medicine 2012. Twenty-two patients with sarcoidosis and symptoms of small fibre neuropathy, randomised double-blind to ARA 290 (n = 12) or placebo (n = 10), all with baseline pain scores of 5 or more. The small fibre neuropathy screening list score improved significantly against placebo (−11.5 ± 3.04 vs −2.9 ± 3.34); Brief Pain Inventory and fatigue scores improved equivalently in both groups. No safety concerns were raised.

humansubcutaneous, once daily for 28 days

4 mg per day

Dahan et al., Molecular Medicine 2013. Thirty-eight patients with sarcoidosis-associated small nerve fibre loss, 21 on ARA 290 and 17 on placebo. Corneal nerve fibre area rose by a median 14.5% on ARA 290 (p = 0.022) against a 5.3% fall on placebo; the symptom screening score improved 28% versus 9%; the six-minute walk test improved 18.7 m versus a 15.1 m decline. Intraepidermal nerve fibre density did not change at 28 days. No serious adverse events during dosing or 12 weeks of follow-up.

humansubcutaneous and intravenous, crossover pharmacokinetic study

2 mg IV compared with 2, 4 and 6 mg subcutaneously

Dahan et al., Molecular Medicine 2013. Ten normal volunteers. This is the study that chose the 4 mg subcutaneous dose used everywhere afterwards: measured as area under the curve above the ~1.3 ng/mL activation threshold, 2 mg IV gave 65 ng/mL·min, 2 mg SC gave 23, 4 mg SC gave 59 and 6 mg gave 249. The 4 mg subcutaneous dose was selected as the one approximating the intravenous exposure of the earlier trial.

humansubcutaneous, once daily for 28 days

1 mg, 4 mg or 8 mg per day, against placebo

Culver et al., IOVS 2017 (NCT02039687) — the largest trial, a phase 2b in 64 subjects with sarcoid-associated small nerve fibre loss and neuropathic pain. Placebo-corrected change in corneal nerve fibre area at day 28 was 109 µm² (95% CI −429 to 647) at 1 mg, 697 µm² (159 to 1236; p = 0.012) at 4 mg and 431 µm² (−130 to 992) at 8 mg. Only 4 mg separated from placebo, and 8 mg did not do better. Pain improved in all groups including placebo, and the placebo-corrected pain result at 4 mg was not significant (p = 0.157).

humansubcutaneous, self-administered once daily for 28 days

4 mg per day

Brines et al., Molecular Medicine 2015. Phase 2 study in subjects with type 2 diabetes and painful neuropathy, followed for a further month after dosing stopped (registered as NCT01933529, listed enrolment 24). HbA1c and lipid profiles improved over the 56-day observation period and PainDetect scores improved significantly; subjects whose corneal nerve fibre density was more than one standard deviation below normal showed an increase. The authors framed the result as deserving continued evaluation, which is what it received and did not survive.

How good is the evidence?

Better than most research peptides and still short of the finish line. Three randomised, placebo-controlled human trials were published between 2012 and 2017 — a 22-patient intravenous pilot, a 38-patient subcutaneous trial and a 64-patient phase 2b dose-ranging study — all in sarcoidosis-associated small-fibre neuropathy, plus a smaller phase 2 study in type 2 diabetes. They consistently reported increases in corneal nerve fibre measures and improvements on neuropathy symptom questionnaires, with no serious adverse events. What they did not produce is a phase 3 trial, an approval, or evidence for any of the uses ARA-290 is marketed for online. The largest trial's primary endpoint was a surrogate — corneal nerve fibre area — and its pain endpoint did not reach significance in the placebo-corrected comparison. Development has since stalled, and a 2016 diabetic macular oedema trial was terminated.

ARA-290 peptide dosage: the 4 mg figure and where it comes from

Almost every ARA-290 dose in circulation traces back to one number: 4 mg subcutaneously once daily for 28 days. It is not arbitrary. A crossover pharmacokinetic study in ten volunteers compared a 2 mg intravenous dose against 2, 4 and 6 mg subcutaneously, and 4 mg subcutaneous was the dose whose exposure above the receptor activation threshold came closest to the intravenous dose used in the earlier pilot. That is how it entered the 2013 trial and the 2015 diabetes study.

The phase 2b study then tested 1, 4 and 8 mg daily against placebo in 64 subjects. Only 4 mg separated from placebo on the primary endpoint, and 8 mg was no better than 4 mg — a flat or inverted top to the dose-response curve, not a ladder to climb. Everything published used a 28-day course. There is no published evidence about what happens beyond 28 days, at any dose.

A two-minute peptide with month-long effects

ARA-290's plasma half-life is roughly two minutes. It works by activating the innate repair receptor — a heterodimer of the EPO receptor and the β-common receptor that is not normally expressed in healthy tissue but is induced by injury or inflammation — which is also why it does not raise haematocrit the way erythropoietin does. The reviewers who characterised it describe a short-lived peptide flipping a molecular switch whose downstream effects persist long after the drug is gone.

That matters for reading the dose table. Exposure in these trials was quantified as time spent above an activation threshold of about 1.3 ng/mL, not as a steady blood level. It is the reason a once-daily injection of a two-minute peptide was a coherent design, and the reason doubling the dose to 8 mg added nothing.

What ARA-290 has not been shown to do

Every published human trial is in neuropathy — sarcoidosis-associated small-fibre neuropathy in three of them, diabetic neuropathy in the fourth. ARA-290 is marketed online for general healing, injury recovery, inflammation and anti-ageing. None of those has been tested in a human trial, and a corneal nerve fibre measurement in a sarcoidosis patient is not evidence for any of them.

Nor did the programme finish. The largest trial's primary endpoint was a surrogate measure, its placebo-corrected pain result did not reach significance, a diabetic macular oedema trial was terminated, and no phase 3 trial has been published. The compound sits on the FDA's 503A list in Category 3, the bucket for nominations that arrived without enough supporting information to evaluate.

Common questions

Sources

Every number on this page comes from one of the documents below. Where no reliable source exists, the page says so instead of filling the gap.

RegulatorFDA· 2026-05-14
Bulk Drug Substances Nominated for Use in Compounding Under Section 503A
RegulatorFDA
Certain Bulk Drug Substances for Use in Compounding May Present Significant Safety Risks
RegulatorWorld Anti-Doping Agency· 2026
WADA 2026 Prohibited List
ReferenceNIH / National Center for Biotechnology Information
PubChem compound records (molecular weights and formulae)
ReferenceU.S. National Library of Medicine
ClinicalTrials.gov trial registry
Published studyMolecular Medicine· 2012-11
Heij L et al. Safety and efficacy of ARA 290 in sarcoidosis patients with symptoms of small fiber neuropathy: a randomized, double-blind pilot study
Published studyMolecular Medicine· 2013-11
Dahan A et al. ARA 290 improves symptoms in patients with sarcoidosis-associated small nerve fiber loss and increases corneal nerve fiber density
Published studyInvestigative Ophthalmology & Visual Science· 2017-05
Culver DA et al. Cibinetide improves corneal nerve fiber abundance in patients with sarcoidosis-associated small nerve fiber loss and neuropathic pain
Published studyMolecular Medicine· 2015-03
Brines M et al. ARA 290, a nonerythropoietic peptide engineered from erythropoietin, improves metabolic control and neuropathic symptoms in patients with type 2 diabetes
Published studyPharmacology & Therapeutics· 2015-07
Collino M et al. Flipping the molecular switch for innate protection and repair of tissues: long-lasting effects of a non-erythropoietic small peptide engineered from erythropoietin
Published studyExpert Opinion on Investigational Drugs· 2014-04
van Velzen M et al. ARA 290 for treatment of small fiber neuropathy in sarcoidosis
ReferenceClinicalTrials.gov· 2015-02
NCT02039687 — Study of Efficacy of ARA 290 on Corneal Nerve Fiber Density and Neuropathic Symptoms of Subjects With Sarcoidosis
ReferenceClinicalTrials.gov· 2015-09
NCT01933529 — ARA290 in prediabetes and type 2 diabetes, a phase II study
ReferenceClinicalTrials.gov
NCT06626971 — The Use of ARA290 for the Treatment of Diabetic Macular Oedema (terminated)
ReferenceAraim Pharmaceuticals (press release)· 2017-05-08
Araim Pharmaceuticals' cibinetide (ARA 290) regenerates small nerve fibers and improves neuropathic clinical symptoms in the orphan disease of sarcoidosis