What Is Ara-290? Dosage, Half-Life & How to Track It

What Ara-290 is and how it works

Ara-290 is a synthetic 11-amino-acid peptide modeled on the “helix B” region of erythropoietin (EPO) — the hormone your kidneys make to trigger red blood cell production. The engineering trick is that Ara-290 was designed to lose EPO’s affinity for the classic EPO receptor (the one that drives red-cell production and carries clotting risk) while keeping affinity for a different target.

That different target is the innate repair receptor (IRR) — a heterodimer built from one EPO-receptor subunit and CD131, a receptor shared with several other cytokines. Activating the IRR triggers anti-inflammatory and tissue-protective signaling without touching red-cell production, which is why Ara-290 is described as “non-erythropoietic” — it does EPO’s protective job without EPO’s blood-thickening side effect.

This isn’t purely theoretical: Ara-290/cibinetide has been through actual human Phase 2 clinical trials for diabetic peripheral neuropathy and for small-fiber neuropathy associated with sarcoidosis, with some positive nerve-fiber and pain-score results reported. It remains investigational — not FDA-approved — and outside a trial setting it’s sourced and dosed as a research peptide.

Typical dosing & reconstitution

Ara-290 ships lyophilized and is reconstituted with bacteriostatic water. Trial-derived protocols use a target dose of 4 mg once daily subcutaneously, often preceded by a lower 2 mg dose in the first week to gauge tolerance — trial data found no extra benefit pushing past 4 mg/day.

Reconstitution sets your concentration and syringe units:

At 8 mg/mL, a 4 mg dose is 50 units — half a standard 1 mL insulin syringe. That’s a notably strong concentration compared to most peptides, exactly the kind of vial-to-dose math the reconstitution calculator checks before you draw anything up.

Half-life & what it means for frequency

As an 11-amino-acid peptide with no half-life-extending modification, Ara-290’s plasma half-life is short — on the order of minutes, not hours — consistent with other unmodified small peptide fragments. Once-daily dosing isn’t based on that plasma level, though: activating the IRR triggers downstream anti-inflammatory signaling that persists far longer, on the order of 24–72 hours, which is what actually supports a once-a-day schedule despite the fast plasma clearance.

Because there’s no depot effect, the daily dose does the entire job each day; there’s no accumulating background level to lean on the way there is with a long-half-life compound, so consistency matters more than with something dosed weekly.

What to track & common side effects

In trial settings, Ara-290 has been reported as generally well tolerated, with injection-site reactions the most common issue. Because the molecule is specifically engineered to avoid EPO’s blood-thickening effects, it doesn’t carry the clotting-risk profile of actual EPO or ESAs — but outside its trial-approved use it remains a research peptide, so sourcing and quality matter.

What’s worth tracking: the daily dose (especially the week-1 step-up from 2 mg to 4 mg), and whatever nerve or inflammation symptom motivated starting it — trial endpoints were things like nerve-fiber density and pain scores, which in practice means watching your own symptom trend over weeks.

Frequently asked questions