ARA-290 is the first compound shown to regenerate small fiber nerves in humans — not suppress pain, not slow degeneration, but measurably regrow nerve fibers. Phase 2 trials in sarcoidosis patients documented 23% increases in corneal nerve fiber area, confirmed by confocal microscopy. For the burning, tingling, and numbness that gabapentin and pregabalin can mask but never reverse, this is a different category of intervention.
The molecule was reverse-engineered from erythropoietin's three-dimensional structure. EPO's helix B surface contacts a receptor complex (the innate repair receptor) that triggers tissue protection only where injury exists. ARA-290 replicates that geometry in 11 amino acids — delivering EPO's protective benefits without blood thickening, thrombosis risk, or hemoglobin monitoring. It has FDA Fast Track and Orphan Drug designation for sarcoidosis; development stalled after 2020 due to funding, not science.
Where ARA-290 is most compelling: neuropathic pain that hasn't responded to conventional management, small fiber neuropathy from any cause, and tissue protection during inflammatory conditions. It pairs with BPC-157 and TB-500 when nerve pain coexists with structural tissue damage.
| At a Glance | |
|---|---|
| Dosage | 4 mg subcutaneous, daily. |
| Protocol | 4–8 weeks (28–84 days), single course. Morning, empty stomach. Thigh injection with rotating sites. |
| Results timeline | Neuropathic symptoms improve within 1–2 weeks, with nerve regeneration markers continuing to improve over the full course and effects persisting months after discontinuation. |
| Side effects | Mild injection site reactions and transient headache — adverse event rates comparable to placebo across Phase 2 trials, with no hematological changes. |
| Regulatory status | FDA Fast Track and Orphan Drug designation for sarcoidosis. Not approved — Phase 3 funding gap, not scientific failure. |
| Best stacked with | BPC-157, TB-500 when nerve pain coexists with structural tissue damage. NAD+ for metabolic support during nerve repair. |
What ARA-290 Is
ARA-290 (also called cibinetide) is an engineered peptide that was reverse-engineered from erythropoietin's three-dimensional structure. When researchers mapped EPO's shape, they found that one surface — helix B — faces away from the receptor responsible for making red blood cells. This surface instead contacts a different receptor complex that triggers tissue repair.
The peptide sequence was extracted from this helix B region: 11 amino acids with no sequence similarity to EPO itself, but recapitulating the three-dimensional geometry that activates repair pathways.
The result is a molecule that provides EPO's protective benefits without its liabilities — no blood thickening, no thrombosis risk, no need for hemoglobin monitoring.
How ARA-290 Works
The Innate Repair Receptor
Normal tissues don't express the innate repair receptor (IRR). It appears rapidly in response to injury, inflammation, hypoxia, or metabolic stress — acting as a damage sensor that summons repair resources only where needed.
The IRR is a heterodimer of two receptor subunits: EPOR and CD131 (beta-common receptor). When ARA-290 binds this complex, it triggers signaling cascades that reduce inflammation and support regeneration:
JAK2/STAT signaling: Anti-apoptotic effects — damaged cells are rescued rather than eliminated prematurely.
PI3K/Akt pathway: Modulates cell survival, stem cell migration, and regional blood flow to injured areas.
NF-kB downregulation: Reduces proinflammatory cytokine production, particularly TNF-alpha — quieting the inflammatory response that can become self-perpetuating.
Why It Doesn't Make Red Blood Cells
EPO's blood-making effects require binding to EPOR homodimers in bone marrow — a completely different receptor configuration. ARA-290 doesn't engage this receptor at all. CD131 knockout studies confirm this: animals lacking the beta-common receptor subunit lose all tissue-protective effects from ARA-290, but erythropoiesis continues normally.
This means no polycythemia (thick blood), no thrombosis risk, no hypertension from volume overload — the dangerous side effects that limit EPO use in clinical practice.
| Feature | EPO (Erythropoietic) | ARA-290 (Tissue Protective) |
|---|---|---|
| Receptor | EPOR homodimer | EPOR-CD131 heterodimer (IRR) |
| Primary effect | RBC production | Tissue protection/repair |
| Thrombosis risk | Yes | No |
| Hemoglobin monitoring | Required | Not required |
Clinical Evidence: What Trials Show
Sarcoidosis Small Fiber Neuropathy
The strongest clinical data comes from sarcoidosis patients with painful small fiber neuropathy — a condition where tiny sensory nerves die back, causing burning pain, numbness, and autonomic dysfunction.
DOSARA Trial (Phase 2b, n=64): Patients received 4 mg subcutaneous cibinetide daily for 28 days. The 4 mg dose group showed a 23% increase in corneal nerve fiber area versus baseline, confirmed by confocal microscopy. Skin biopsies showed increases in GAP-43 positive nerve fibers — a marker of active nerve regeneration, not just nerve survival.
Pain intensity decreased significantly in the moderate-to-severe pain subgroup. Walking distance correlated with nerve fiber density improvements.
Pilot Study (n=22): The earlier proof-of-concept trial showed ARA-290 patients achieved an 11.5-point improvement in Small Fiber Neuropathy Screening List scores versus 2.9 points for placebo. 42% of ARA-290 patients achieved clinically meaningful 15+ point improvements versus 0% in the placebo group.
Why This Matters
This is the first drug to demonstrate actual small nerve fiber regeneration in humans. Existing neuropathy treatments only suppress symptoms (gabapentin, duloxetine) or slow progression. ARA-290 shows biological reversal — new nerve fibers growing where old ones had died.
| Trial | Phase | N | Primary Endpoint | Result |
|---|---|---|---|---|
| DOSARA (Sarcoidosis) | 2b | 64 | Corneal nerve fiber area | 23% increase |
| Sarcoidosis Pilot | 2 | 22 | SFNSL score | 11.5 vs 2.9 points |
| Type 2 Diabetes | 2 | ~40 | Metabolic/neuropathy | Improved |
| Diabetic Macular Edema | 2 | 9 | BCVA, retinal thickness | Not met |
Other Indications (Earlier Stage)
Type 2 Diabetes: Subjects receiving ARA-290 showed improvements in HbA1c, lipid profiles, and corneal nerve fiber density in those with baseline deficits.
Diabetic Macular Edema (n=9): This small open-label study failed to meet primary endpoints for visual acuity and retinal thickness, though some participants showed individual improvements. The small sample size limits conclusions.
Preclinical promise: Animal studies show ARA-290 protects kidneys during transplantation (reduced ischemia-reperfusion injury), reduces infarct size after heart attack, and provides neuroprotection in stroke and traumatic brain injury models. The peptide crosses the blood-brain barrier.
Who ARA-290 May Benefit
| Profile | Why ARA-290 Helps |
|---|---|
| Small fiber neuropathy | First drug to show nerve regeneration in this condition |
| Sarcoidosis patients | FDA Fast Track + Orphan Drug designation for this population |
| Diabetic neuropathy | Preclinical and Phase 2 data show nerve fiber improvements |
| Post-viral nerve damage | IRR mechanism targets injury-induced inflammation |
| Chemotherapy-induced neuropathy | Theoretical fit (IRR upregulates with metabolic stress) |
The peptide works best when the innate repair receptor is actually expressed — meaning active injury, inflammation, or metabolic stress. It's less likely to help when nerves have already completely degenerated without ongoing insult.
Dosing
Reconstitution note: Use bacteriostatic water with sodium chloride (isotonic) to reduce injection site sting and prevent welts. Use the reconstitution calculator to determine exact volumes.
| Clinical Trial Protocol | |
|---|---|
| Standard dose | 4 mg SC daily |
| Dose range tested | 1–8 mg daily |
| Treatment duration | 28–84 days |
| Route | Subcutaneous (thigh, rotating sites) |
The 4 mg dose showed the clearest efficacy signal. Doses up to 8 mg were tested without dose-limiting toxicity.
Pharmacokinetics
ARA-290 has a paradoxically short plasma half-life of approximately 2–20 minutes. Yet biological effects persist because receptor activation triggers sustained intracellular signaling cascades — the receptor acts as a "molecular switch" that stays on after the ligand clears.
Peak plasma concentration after 4 mg SC reaches approximately 3 ng/mL (2.4 nmol/L), exceeding the minimum effective concentration of 1 nmol/L.
Side Effects and Safety
ARA-290 has an excellent safety profile across multiple Phase 2 trials.
Common:
- Mild injection site reactions
- Transient headache
Serious events:
- Adverse event frequency was comparable between ARA-290 and placebo groups
- No clinically significant hematological changes (confirms no erythropoietic activity)
- No anti-cibinetide antibodies detected
Safety Advantage Over EPO
The critical benefit: ARA-290 eliminates the major risks that limit EPO therapy:
| Concern | EPO | ARA-290 |
|---|---|---|
| Thrombosis | Increased risk | Not observed |
| Polycythemia | Can occur | Not observed |
| Hypertension | Can occur | Not observed |
| Pure red cell aplasia | Risk with antibodies | Not applicable |
This safety profile makes ARA-290 usable in populations where EPO would be dangerous — cardiovascular patients, those with clotting disorders, or anyone at thrombotic risk.
Development Status: The Funding Gap
Despite promising Phase 2 results and regulatory fast-tracking, ARA-290 development has stalled.
Achievements:
- US and EU Orphan Drug Designation for sarcoidosis
- US FDA Fast Track Designation for sarcoidosis-associated small fiber neuropathy
- Successful End-of-Phase 2 FDA meeting (2017)
- EU Orphan Designation for pancreatic islet transplantation
Current status:
- No Phase 3 trials announced or registered
- Araim Pharmaceuticals (the developer) shows no public activity since July 2020
- Total funding of only $8.1M — insufficient for Phase 3 ($50–100M+ typically required)
- 1–10 employees as of last update
The most likely explanation is insufficient capital to fund Phase 3 trials combined with difficulty attracting pharmaceutical partners despite orphan drug designations. The science was successful; the business model wasn't.
Academic research continues: A 2023 study showed ARA-290 reduced cardiac aging hallmarks and preserved ejection fraction in mice. A 2024 study confirmed brain tissue protection through the beta-common receptor in stroke models. The scientific community sees ongoing value in the mechanism.
FAQ
What is the recommended ARA-290 dosage and protocol?
ARA-290 is dosed at 4 mg subcutaneously once daily, injected in the thigh with rotating sites. Standard courses run 4–8 weeks (28–84 days). Timing is morning on an empty stomach. Clinical trials tested doses from 1–8 mg daily, but 4 mg emerged as the effective standard. Despite a very short plasma half-life of 2–20 minutes, effects persist because receptor activation triggers sustained intracellular signaling cascades — the receptor acts as a molecular switch that stays on after the ligand clears. Most protocols involve a single course, with repeat cycles if symptoms recur after 3–6 months.
Does ARA-290 need to be cycled or can I take it continuously?
ARA-290 is typically used as a single defined course rather than cycled repeatedly. A 4–8 week course is the standard, with effects persisting for months after discontinuation due to sustained intracellular signaling. Repeat courses are appropriate if symptoms recur after 3–6 months. This is not a compound that requires or benefits from continuous long-term use — it initiates a repair process that continues after dosing stops.
What is ARA-290 used for?
ARA-290's most advanced indication is sarcoidosis-associated small fiber neuropathy, where Phase 2 trials showed nerve regeneration. Preclinical data suggests potential for kidney protection during transplantation, cardiac protection, stroke, and other conditions involving tissue injury.
Is ARA-290 the same as EPO?
No. ARA-290 was derived from EPO's structure but activates a different receptor. It provides tissue protection without making red blood cells — eliminating the thrombosis, polycythemia, and hypertension risks of EPO.
Why isn't ARA-290 FDA approved?
Despite successful Phase 2 trials and FDA Fast Track designation, no Phase 3 trials have been conducted due to funding constraints. The developing company appears to have run out of capital before completing the approval process.
Can ARA-290 regenerate nerves?
Clinical data suggests yes — Phase 2 trials showed 23% increases in corneal nerve fiber area and increases in regenerating nerve fibers in skin biopsies. This is the first drug to demonstrate small fiber nerve regeneration in humans.
Where can I get ARA-290?
ARA-290 is not commercially available. The developing company (Araim Pharmaceuticals) appears inactive since 2020. Your options are limited to research peptide suppliers of variable quality. Unlike more common peptides, ARA-290 has fewer suppliers and less quality verification in the market. Some compounding pharmacies may be able to source it, but availability is inconsistent.
Is ARA-290 being developed for other conditions?
Officially, development stalled after Phase 2. However, academic research continues exploring the mechanism. A 2023 study showed cardiac protection effects in aging mice. A 2024 study confirmed neuroprotection in stroke models. The innate repair receptor mechanism has theoretical applications in kidney transplant protection, heart attack, TBI, and diabetic complications—but without commercial development, these remain preclinical observations rather than active drug programs.
How does ARA-290 compare to BPC-157 for nerve healing?
They work through different mechanisms. ARA-290 activates the innate repair receptor specifically at sites of injury, with Phase 2 clinical trial data showing measurable nerve regeneration. BPC-157 has extensive preclinical data on healing (including nerve repair) but no completed human trials for neuropathy. ARA-290 has the stronger human evidence base; BPC-157 has the broader anecdotal use and easier availability. They could theoretically complement each other since their mechanisms don't overlap.
ARA-290 for Nerve Pain
Some injuries don't heal because neuropathic signaling persists long after tissue damage resolves.
The tissue looks fine on imaging. Structural repair is progressing. But burning pain, electric sensations, and allodynia persist. Guarding reflexes don't match tissue integrity. Movement feels effortful despite adequate strength. The brain keeps receiving "danger" signals from small nerve fibers that haven't recovered.
This is where ARA-290 (Cibinetide) fits. It's an 11-amino-acid peptide derived from the tissue-protective region of erythropoietin—designed to activate the innate repair receptor and quiet neuropathic symptoms without thickening the blood or raising hematocrit.
ARA-290 is not a healing peptide for tendons or collagen. It's a nerve-repair module for when small-fiber neuropathy is the bottleneck blocking rehab.
| Nerve Pain At a Glance | |
|---|---|
| What it is | Non-erythropoietic EPO fragment (11 amino acids) |
| Mechanism | Activates innate repair receptor (EPO-β + IL-4Rα) |
| Primary effect | Small-fiber nerve protection and regeneration |
| Secondary effect | Anti-inflammatory, M2 macrophage polarization |
| Dose | 4 mg subcutaneous daily |
| Cycle | 4–8 weeks (modeled on clinical trials) |
| When to use | Neuropathic symptoms blocking rehab progress |
Key principle: ARA-290 is a specialized nerve module, not a general-purpose repair peptide. Use it when burning/tingling/allodynia is the limiting factor.
Who Should Use ARA-290 for Nerve Pain
Use ARA-290 If:
- Burning, dysesthesia, or "electric" pain persists despite structural healing
- Allodynia (pain from light touch) at or near the injury site
- Guarding reflexes don't match tissue integrity—the brain thinks there's more damage than exists
- Ghost pain that MRI can't explain
- Movement feels effortful despite adequate strength
- Autonomic small-fiber features (temperature dysregulation, altered sweating) worsen with rehab
Skip ARA-290 If:
- Pain is mechanical/soreness-dominant (improves predictably with load management)
- Pain is clearly inflammatory (swelling, warmth, redness) → KPV or NSAIDs
- No sensory symptoms—just stiffness or weakness
- Symptoms are clearly structural (imaging shows ongoing damage)
- Tissue is still cold and poorly perfused → Need BPC-157/TB-500 first
Do I Need the Base Protocol First?
Not required, but often complementary. ARA-290 addresses a specific bottleneck—neuropathic symptoms—that the base protocol doesn't fully resolve.
| Scenario | Recommendation |
|---|---|
| Nerve symptoms are the clear, primary limiter | ARA-290 can be used early |
| Running base protocol with persistent nerve pain | Add ARA-290 |
| Tissue is still poorly perfused/healing | Start with BPC-157 + TB-500 |
| Multiple bottlenecks (energy, inflammation, nerves) | Use 5-compound base + ARA-290 |
ARA-290 is layered onto structural repair stacks when nerve symptoms are limiting. If tissue lacks blood flow or cellular mobility, address those first.
How ARA-290 Works for Nerve Pain
The Problem: Small-Fiber Nerve Damage
Injuries don't just damage tendons and ligaments—they damage the small nerve fibers that provide sensation, proprioception, and autonomic regulation. When these fibers are injured:
- They send persistent "danger" signals (burning, tingling, electric pain)
- Proprioception is impaired (movement feels uncertain)
- The brain maintains guarding reflexes even after tissue heals
- Rehab becomes "two steps forward, one step back" because the nervous system won't allow full loading
Standard repair peptides (BPC-157, TB-500, GHK-Cu) address vascular access, cellular mobility, and collagen quality—but they don't directly target small-fiber nerve regeneration.
What Makes ARA-290 Different
ARA-290 is engineered from the tissue-protective region of erythropoietin (EPO). But unlike full-length EPO:
| Full EPO | ARA-290 |
|---|---|
| Binds erythropoietic receptor | Binds innate repair receptor (IRR) |
| Raises hematocrit/hemoglobin | No erythropoietic effect |
| Thickens blood | No thrombotic signal |
| Red cell production | Tissue protection and nerve repair |
The Innate Repair Receptor (IRR) is a heterodimer of EPO-β and CD131. When activated by ARA-290:
| Pathway | Effect | What You Notice |
|---|---|---|
| Anti-apoptotic cascades | Protects small-fiber nerves from death | Burning and tingling fade |
| M1→M2 macrophage shift | Local inflammation resolves without immunosuppression | Less irritability at nerve sites |
| NF-κB downregulation | Reduces inflammatory cytokines (IL-6, TNF-α) | Calmer tissue; less flare |
| Nerve regeneration support | Promotes small-fiber nerve sprouting | Improved proprioception, less guarding |
| Microvascular protection | Restores blood-nerve barrier | Better perfusion to nerve endings |
Who Responds Best
ARA-290 appears most effective for:
| Phenotype | Response |
|---|---|
| Burning, dysesthetic neuropathic pain | Strong |
| Diabetic or metabolic small-fiber neuropathy | Studied |
| Immune-mediated SFN (sarcoid-like, post-infectious) | Studied |
| Autonomic small-fiber features | Modest improvement |
| Mechanical/soreness pain | Unlikely to help |
| Nerve Pain Dosing Protocol | |
|---|---|
| Dose | 4 mg |
| Frequency | Daily (morning) |
| Route | Subcutaneous |
| Cycle | 4–8 weeks |
| Timing | Morning, empty stomach |
Implementation Notes
- Morning dosing for nerve perfusion effects
- Empty stomach maximizes absorption
- Don't escalate beyond 4 mg daily—this matches the clinical trial protocol
- Inject alone—separate syringe from other peptides
- Short courses (4 weeks) often produce benefits that persist for months
Alternative Protocol (Modeled on Sarcoid Trials)
If subcutaneous daily isn't feasible:
- 2 mg IV 3× weekly for 4 weeks (requires clinical setting)
- Similar outcomes in sarcoidosis studies
Nerve Pain Timeline
Weeks 1–2
- What's happening: IRR activation; anti-apoptotic cascades engaging
- What you notice: Sensory symptoms starting to quiet; less burning
- Challenge: Stay consistent; effects build over time
Weeks 2–4
- What's happening: Small-fiber protection established; M2 macrophage shift
- What you notice: Tingling reduced; movement feels less guarded
- Decision point: Most of the benefit occurs by week 4
Weeks 4–8
- What's happening: Nerve regeneration support
- What you notice: Proprioception improving; can load more confidently
- Stopping point: Clinical trials used 4-week courses with lasting benefit
After Stopping
In clinical trials, benefits persisted months after the last dose:
- painDETECT improvements maintained at 8 weeks (4 weeks post-dosing)
- SFNSL improvements maintained at 16 weeks (12 weeks post-dosing)
- CNFD (corneal nerve fiber density) continued to improve after dosing stopped
This suggests ARA-290 triggers a repair process that continues after the compound is cleared.
Signs ARA-290 Is Working
- Burning and tingling symptoms fading (usually by weeks 2–4)
- Movement feels less guarded
- Proprioception improving (balance, coordination)
- Can tolerate physical therapy without nerve-related flares
- Guarding reflexes diminishing
If Issues Persist
If nerve symptoms resolve but recovery timing issues persist (sleep disruption, unpredictable flares), consider Tesamorelin for GH timing support.
If you still experience relapse under load (progress then flare with intensity), consider SS-31 for mitochondrial stability.
Maintenance Options
ARA-290 is typically used as a defined 4–8 week course rather than ongoing therapy. Based on clinical trial patterns:
- Single course: Often sufficient; benefits persist months post-dosing
- Repeat course: If symptoms recur after 3–6 months, another 4-week course may help
- Maintenance use: Not established; trials didn't study continuous long-term dosing
Nerve Pain FAQ
What kind of pain does ARA-290 help with?
ARA-290 is specifically for neuropathic pain—burning, tingling, electric sensations, allodynia (pain from light touch), and dysesthesia. It does not help with mechanical/soreness pain, inflammatory pain, or structural damage.
How quickly does ARA-290 work?
Most people notice sensory symptoms starting to quiet within 2–4 weeks. In clinical trials, significant improvements occurred by week 4 of dosing and continued to improve even after stopping.
Do benefits last after stopping ARA-290?
Yes. In clinical trials, benefits persisted months after the 4-week dosing course ended. This suggests ARA-290 triggers a repair process rather than just masking symptoms.
Do I need the base protocol to use ARA-290?
Not required. ARA-290 addresses a specific bottleneck (nerve-related symptoms) that the base protocol doesn't fully resolve. However, if tissue is still poorly perfused or structurally damaged, address those issues first with BPC-157/TB-500.
Can I use ARA-290 with Tesamorelin?
Yes. They work through completely different pathways and don't interfere with each other. Use Tesamorelin at night for GH timing; ARA-290 in the morning for nerve support.
What if my pain is both neuropathic AND structural?
Use both structural repair compounds (BPC-157, TB-500) and ARA-290. They address different bottlenecks and are complementary.
Are there long-term risks?
Unknown. Trial durations were 4–8 weeks with months of follow-up. No concerning signals emerged, but there are no multi-year safety datasets. The conservative approach is to use defined courses (4–8 weeks) rather than indefinite treatment.
Related Topics
- NAD+ Guide — cellular energy support for nerve function
- SS-31 Guide — mitochondrial repair peptide
- Semax vs Selank — cognitive and neuroprotective peptides
- MOTS-c Guide — mitochondrial-derived peptide
- BPC-157 Guide — Core repair peptide for vascular access and tissue healing
- TB-500 Guide — Thymosin Beta-4 for cellular mobility and repair
- Tesamorelin Guide — GH-axis support often layered after nerve pain resolves
- GHK-Cu Guide — Collagen and tissue quality after nerve symptoms resolve
- Reconstitution Guide — Step-by-step peptide mixing guide
- Injury Recovery Protocol — ARA-290 is the nerve pain addition for neuropathic injuries
- GLOW & KLOW Protocol — Multi-bottleneck injury protocol
References
- Brines M. Discovery of a Master Regulator of Injury and Healing. Mol Med 2014. Discovery of a master regulator of injury and healing (PMCID: PMC4374522)
- Brines M, et al. ARA 290, a Nonerythropoietic Peptide Engineered from Erythropoietin, Improves Metabolic Control. Mol Med 2015. ARA 290 improves metabolic control (PMCID: PMC4365069)
- Dahan A, et al. Targeting the innate repair receptor to treat neuropathy. Pain Rep 2017. Innate repair receptor targeting in neuropathy (PMCID: PMC5741312)
- Heij L, et al. ARA 290 in Sarcoidosis SFN. Mol Med 2012. ARA 290 in sarcoidosis small-fiber neuropathy (PMCID: PMC3563705)
- Araim Pharmaceuticals. Cibinetide Regenerates Small Nerve Fibers. PRNewswire 2017.
- PMC3567997. ARA290 attenuates renal ischemia/reperfusion injury. 2013.
- CNS Neuroscience & Therapeutics. ARA290 brain tissue protection in cerebral ischemic stroke. 2024. ARA290 brain tissue protection after ischemic stroke
Medical Disclaimer
The content in this protocol guide is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider before beginning any new protocol, supplement, or medication.