Carl read the papersWhat it actually is
ARA-290 is a short peptide derived from the helix B region of erythropoietin. EPO is best known for raising red blood cell count, but it also signals tissue protection and repair through a separate receptor.
ARA-290 was engineered to activate only that second pathway — the innate repair receptor. It is non-erythropoietic: it does not raise haematocrit, which should sidestep the clotting risk that makes EPO itself dangerous outside of medical supervision.
How it’s thought to work
- Innate repair receptor agonism — Proposed to bind the IRR — an EPO receptor and beta-common receptor heterodimer — expressed on injured tissue.
- Anti-inflammatory signalling — Downregulates pro-inflammatory cytokine cascades at sites of tissue damage.
- Small-fibre nerve repair — The most-studied application — regrowth of small sensory nerve fibres, measured by corneal nerve fibre density.
- No erythropoiesis — The defining feature. It does not raise red cell count, so it should not carry EPO's clotting risk.
What the research says
Better than most of this shelf. Phase 2 trials ran in sarcoidosis-associated small-fibre neuropathy and in type 2 diabetes, mostly at 4 mg subcutaneously once daily for 28 days (the first small sarcoid trial used IV dosing). A dose-ranging study compared 1 mg, 4 mg and 8 mg daily for 28 days — the 4 mg arm produced the largest placebo-corrected increase in corneal nerve fibre area, meaning more was not better.
- Phase 2 in sarcoid small-fibre neuropathy — 4 mg SC daily, 28 days.
- Dose-ranging 1 / 4 / 8 mg: only the 4 mg arm clearly beat placebo on nerve fibre area; 8 mg did not.
- Non-erythropoietic — no haematocrit rise, so EPO's clotting risk is not expected.
- Pain scores improved in the earlier trials. In the 2017 dose-ranging trial pain fell in every group, placebo included.
Watch: ARA-290 explained
Video by Peptides-explained-easy on YouTube. Not affiliated with Peptide Carl and not an endorsement — included because a second explanation of the same mechanism is often what makes it click.
Reported protocols
These are the doses the peptide community actually reports running (Reddit & forums), alongside published research — logged for education, not as a recommendation to use.
| Parameter | Commonly reported range |
|---|---|
| Trial dose | 4 mg subcutaneously once daily for 28 days — the dose that performed best in dose-ranging |
| Range tested | 1 mg, 4 mg and 8 mg daily. 8 mg did not beat 4 mg |
| Community dose | Frequently reported well below 4 mg, largely because 4 mg/day empties a vial quickly |
| Route | Subcutaneous |
| Cycle | 28 days is the studied duration |
| Community tip | Check your units. Almost everything else in this directory is dosed in micrograms; this is dosed in whole milligrams. A 5 mg vial is roughly one day at the trial dose, which surprises people who assume it will last a month. |
Common use cases
| Goal | Community protocol notes |
|---|---|
| Small-fibre neuropathy | 4 mg SC daily for 28 days — the studied protocol |
| Nerve repair research | the corneal nerve fibre measurements are the best-documented endpoint |
| Inflammatory tissue damage | the innate repair receptor is expressed on injured tissue generally |
Mixing it (reconstitution)
Freeze-dried peptides must be reconstituted with bacteriostatic water before they can be measured. Carl’s calculator turns “mg in the vial + ml of water + target dose” into “units on the syringe” — and tells you how long the vial lasts.
→ Open the Reconstitution Calculator
Injection & handling
Subcutaneous, once daily in the studied protocol. The number that matters most here is the unit: trials used 4 mg — not micrograms — once daily for 28 days, which means a 5 mg vial covers roughly one trial-dose day. Reconstitute gently, refrigerate, and use within about 28 days. In dose-ranging only 4 mg clearly beat placebo and 8 mg did not, so there is no case for going higher.
Stacks it appears in
- With BPC-157 — Both appear in nerve and tissue repair discussions through different mechanisms. No interaction data.
- With a mitochondrial compound — SS-31 and similar show up alongside it in neuropathy contexts — again, no combination data.
Sources
- Nonerythropoietic peptides from EPO's helix B, PNAS 2008 (PMID 18676614)
- EPO tissue protection via EPOR/beta-common heteroreceptor, PNAS 2004 (PMID 15456912)
- EPO does not promote EPOR/beta-common interaction, Sci Rep 2018 (PMID 30127368)
- First sarcoid pilot, 2 mg IV three times weekly, Mol Med 2012 (PMID 23168581)
- 28-day SC trial in sarcoid small-fibre loss, Mol Med 2013 (PMID 24136731)
- Phase 2 in type 2 diabetes, 4 mg SC daily for 28 days, Mol Med 2015 (PMID 25387363)
- Phase 2b dose-ranging 1/4/8 mg, Invest Ophthalmol Vis Sci 2017 (PMID 28475703)
- Dose-ranging trial registration (NCT02039687)
- Epogen (epoetin alfa) US label, boxed warning
