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 removes the clotting risk that makes EPO itself dangerous outside of medical supervision.
How it’s thought to work
- Innate repair receptor agonism — Binds 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, and therefore does not carry EPO's thrombotic 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, at 4 mg subcutaneously once daily for 28 days. 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: the 4 mg arm outperformed the 8 mg arm on nerve fibre area.
- Non-erythropoietic — no haematocrit rise, no EPO thrombotic risk.
- Reported improvements in neuropathic pain scores alongside the nerve-fibre measurements.
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. Dose-ranging found 4 mg beat 8 mg, 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.
