Side-by-side · Research reference

ARA 290vsP21

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 2HUMAN-REVIEWED17/59 cited

BAnimal-MechanisticHUMAN-REVIEWED8/36 cited

ARA 290

EPO-Derived Peptide · Innate Repair Receptor Agonist

4 mgDaily doseBrines 2015 Culver 2017

28 daysPhase 2 durationCulver 2017

Non-erythropoieticSafety profileBrines 2015 Liu 2014

SQ · DailyBrines 2015 Culver 2017

P21

CNTF-Derived Neuropeptide · Animal Model Evidence

CNTFR/gp130Primary receptorGuo 2022

Animal onlyEvidence level

NeurogenesisPrimary effectJia 2020 Mottolese 2024

SQ · Site unspecified · Frequency unknown

01Mechanism of Action

Parameter

ARA 290

P21

Primary target

Innate repair receptor (EPO receptor / CD131 heterodimer)

CNTF receptor alpha (CNTFRα) / LIF receptor (LIFR) / gp130 complex on neural stem cells

Pathway

EPO/CD131 → JAK2 activation → PI3K/AKT, MAPK signaling → anti-inflammatory, anti-apoptotic cascades

CNTF mimetic → CNTFRα/LIFR/gp130 heterotrimer → JAK/STAT3 signaling → neurogenesis, stem cell proliferation, neuroprotection

Downstream effect

Tissue protection, nerve fiber regeneration, suppression of inflammatory macrophage activation, altered T-cell differentiation (↑Treg, ↑Th2, ↓Th1)Liu 2014 Culver 2017

Increased neural stem cell self-renewal, globose basal cell activation (Mash1+ cells), olfactory sensory neuron regeneration, hippocampal neurogenesis, neuroprotection in developmental disorders

Feedback intact?

N/A — does not interact with hematopoietic EPO receptorLiu 2014

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Origin

11-amino-acid sequence from EPO helix B, engineered to eliminate hematopoietic activity while retaining tissue-protective properties

Small-molecule peptide mimetic derived from full-length ciliary neurotrophic factor (CNTF), designed to retain receptor activation with improved pharmacokineticsMottolese 2024

Antibody development

Not reported in clinical trials

—

02Dosage Protocols

Parameter

ARA 290

P21

Standard dose (Phase 2)

4 mg / dayBrines 2015 Culver 2017

Sarcoidosis SFN and diabetic neuropathy trials.

—

Frequency

Once daily

Self-administered subcutaneously.

—

Duration

28 days (Phase 2)Culver 2017

Corneal nerve improvements observed by day 28.

Not specified

Evidence basis

Phase 2 RCTsCulver 2017 Brines 2015

64-subject sarcoidosis trial, type 2 diabetes trial.

Animal models only

CDKL5 KO mice, methimazole-induced olfactory injury, CNTF-/- knockout models.Mottolese 2024 Cox 2026 Jia 2020

Route

SubcutaneousBrines 2015

Presumed subcutaneous or intraperitoneal (animal studies)

Timing

Any time of day

No circadian dependence reported.

—

Human dosing

—

No established protocol

No clinical trial data available.

Animal models (mice)

—

Dose and route not specified in abstractsMottolese 2024 Jia 2020

In vitro and in vivo studies demonstrate efficacy; precise dosing protocols not disclosed.

03Metabolic / Fat Loss Evidence

Parameter

ARA 290

P21

Primary effect

Improved metabolic control (HbA1c, fasting glucose)Brines 2015

Secondary to neuropathy treatment; direct lipolytic effects not established.

—

HbA1c

Significant reduction vs placebo

Observed in type 2 diabetes + neuropathy trial.

—

Fasting glucose

Improved in ARA 290 group

—

Body composition

Not directly quantified

Fat loss not a primary endpoint; metabolic improvements may reflect insulin sensitivity.

—

04Side Effects & Safety

Parameter

ARA 290

P21

Injection site reaction

Mild, transient

—

Hematopoiesis

None — non-erythropoietic

Distinguishes ARA 290 from native EPO.

—

Cardiovascular

No thrombotic events or hypertension reported

—

Immunogenicity

No antibody formation reported

—

Tolerability

Well-tolerated in Phase 2 trialsCulver 2017 Brines 2015

—

Human safety data

—

None available

No clinical trials in humans.

Animal tolerability

—

Well-tolerated in mouse models; no toxicity reported in available abstracts

Theoretical risks

—

Uncontrolled stem cell proliferation, immune response to peptide, unknown long-term CNS effects

Absolute Contraindications

ARA 290

·Hypersensitivity to ARA 290

P21

·Use in humans not validated

Relative Contraindications

ARA 290

·Active malignancy (theoretical EPO-axis concern; not observed in trials)

P21

·Active malignancy (theoretical — neurotrophic signaling may affect tumour growth)
·Pregnancy or lactation (no safety data)

05Administration Protocol

Parameter

ARA 290

P21

1. Preparation

Reconstitute lyophilised powder per manufacturer instructions. Use sterile technique.

Not established. No FDA approval, no clinical trial data.

2. Injection site

Subcutaneous — abdomen, thigh, or upper arm. Rotate sites to avoid lipohypertrophy.

In vivo studies used systemic administration (route not specified in abstracts) in mouse models of neurodegeneration, olfactory injury, and CDKL5 deficiency disorder. In vitro studies used primary cell cultures.

3. Timing

Once daily, any time of day. Self-administered in Phase 2 trials.Brines 2015

—

4. Dosing

4 mg daily for 28 days (Phase 2 protocol). Duration for chronic use not established.Culver 2017

—

5. Storage

Lyophilised: store at controlled room temperature. Reconstituted: refrigerate, use within specified timeframe.

—

06Stack Synergy

ARA 290

+ BPC-157

Moderate

View BPC-157 →

ARA 290 targets the innate repair receptor (EPO/CD131) for nerve regeneration and anti-inflammatory signaling, while BPC-157 promotes angiogenesis and tissue repair through distinct mechanisms (likely involving VEGF, growth hormone receptor pathways). Combined, they may address both neuroinflammation and structural tissue repair in neuropathy or injury models. No direct clinical data; mechanistic overlap in tissue protection.

ARA 290: 4 mg SQ · daily
BPC-157: 250–500 mcg SQ · daily
Frequency: Once daily, same or separate injections
Primary benefit: Nerve regeneration, pain reduction, tissue healing

P21

— no documented stacks