Comparison

ARA-290 vs PE-22-28

Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research

ARA-290

Also: Cibinetide, ARA 290

Clinical Trials

ARA-290 (cibinetide) is a synthetic 11-amino-acid peptide carved from the tissue-protective region of erythropoietin (EPO), engineered to calm inflammation and repair nerves without thickening the blood the way EPO does. It has been tested in real Phase 2 human trials, mainly for sarcoidosis-related small fiber neuropathy and diabetic neuropathy, and holds FDA orphan drug status, but it was never approved and development largely stalled. So: genuine clinical data, promising signals, no finish line.

CognitivePhase II/III Trials
PE-22-28

Also: PE22-28, Spadin Analog

Preclinical

PE-22-28 is a seven-amino-acid peptide that blocks a potassium channel in the brain called TREK-1, the same target tied to depression. It is a shortened, more potent and more stable version of spadin, a natural fragment cut from the sortilin propeptide, and it was built to act like a fast antidepressant. All evidence is from rodents. There are no human clinical trials.

CognitiveAnimal Studies

Key Comparison Insights

  • Both peptides belong to the Cognitive category, suggesting similar primary applications.
  • ARA-290 has stronger research evidence (Phase II/III Trials) compared to PE-22-28 (Animal Studies).

Detailed Comparison

AttributeARA-290PE-22-28
CategoryCognitiveCognitive
FDA StatusNot FDA ApprovedNot FDA Approved
Clinical Status
Pre
I
II
III
IV
FDA
Pre
I
II
III
IV
FDA
Mechanism of ActionEPO does two jobs - it tells bone marrow to make red blood cells, and separately it protects and repairs injured tissue. ARA-290 was designed to trigger only the second job. It selectively activates the innate repair receptor (IRR), a heteroreceptor that pairs the EPO receptor with the CD131 beta-common chain and shows up at sites of injury and inflammation. By switching on this receptor, the peptide dampens inflammatory signaling and reduces cell death while leaving red blood cell production alone, which sidesteps EPO's clotting and cardiovascular risks. Some research also links its pain-relieving effect to modulation of the TRPV1 channel where the immune system and nociception intersect.PE-22-28 inhibits TREK-1, a two-pore-domain potassium channel that normally lets potassium leak out of neurons and quiets them down. Block that leak and serotonin-producing neurons in mood-related regions become easier to fire, which is the proposed antidepressant mechanism. This is the same pathway implicated in why TREK-1 knockout mice show a depression-resistant phenotype. Compared to the parent peptide spadin, PE-22-28 binds TREK-1 far more tightly and survives much longer in the body, which is why it was developed. Whether TREK-1 blockade translates into a real antidepressant effect in people remains unproven.
Common Dosing
4 mg daily
Once daily
100-300 mcg intranasal or subcutaneous
Once daily
AdministrationSubcutaneous injectionIntranasal or subcutaneous injection
Typical Duration28-day courses in trialsResearch protocols vary, often 2-4 weeks
Best Time to TakeConsistent daily timingMorning
Possible Side Effects
May vary by individual
  • Generally well-tolerated in trials
  • Injection site reactions
  • No erythropoietic effects (no blood thickening)
  • Not FDA approved
  • Limited safety data (preclinical only)
  • Potential headache
  • Nasal irritation (intranasal use)
  • Theoretical effects on cardiac TREK-1 channels
  • Unknown long-term effects
  • +1 more
Research SummaryARA-290 has more real human data than most peptides in this category. A 2015 phase 2 trial published in Molecular Medicine (Brines et al., registered as NTR3858) found that ARA-290 improved hemoglobin A1c and lipid profile and significantly improved PainDetect neuropathic symptom scores in type 2 diabetes patients, with increased corneal nerve fiber density in those with small fiber neuropathy. In sarcoidosis-associated small fiber neuropathy, controlled studies reported increased corneal nerve fiber area and more regenerating (GAP-43-positive) skin nerve fibers, though in at least one dose-ranging trial pain did not clearly separate from placebo - an honest caveat worth keeping. Tolerability in these small, early-phase studies has been favorable, with no signal of EPO-style blood thickening. That said, the trials are small and early, ARA-290 holds FDA orphan drug status for sarcoidosis neuropathy but is not approved, and the program stalled around 2020. Net: real clinical evidence pointing in a hopeful direction, but not yet proven enough to be a standard treatment.The core data come from a single 2017 paper by Djillani and colleagues in Frontiers in Pharmacology, which screened shortened spadin analogs and found PE-22-28 to be the standout: dramatically stronger TREK-1 inhibition, longer in vivo stability, and antidepressant-like behavior in mice using standard tests like the forced swim and novelty-suppressed feeding paradigms. The same line of work reported that short treatment courses increased hippocampal neurogenesis in rodents, which the authors framed as a possible mechanism for faster mood effects than conventional SSRIs. The broader TREK-1 and spadin story traces back to Mazella et al. in 2010, who first described spadin as a natural antidepressant-type TREK-1 blocker. Importantly, every result is preclinical and in animals. There are no completed or published human efficacy or safety trials of PE-22-28, and it is not an approved drug anywhere. Claims that it treats depression, anxiety, or cognitive decline in people go well beyond what the evidence supports.

Frequently Asked Questions: ARA-290 vs PE-22-28

What is the difference between ARA-290 and PE-22-28?

ARA-290 is a cognitive peptide that ara-290 (cibinetide) is a synthetic 11-amino-acid peptide carved from the tissue-protective region of erythropoietin (epo), engineered to calm inflammation and repair nerves without thickening the blood the way epo does. it has been tested in real phase 2 human trials, mainly for sarcoidosis-related small fiber neuropathy and diabetic neuropathy, and holds fda orphan drug status, but it was never approved and development largely stalled. so: genuine clinical data, promising signals, no finish line. PE-22-28 is a cognitive peptide that pe-22-28 is a seven-amino-acid peptide that blocks a potassium channel in the brain called trek-1, the same target tied to depression. it is a shortened, more potent and more stable version of spadin, a natural fragment cut from the sortilin propeptide, and it was built to act like a fast antidepressant. all evidence is from rodents. there are no human clinical trials. The main differences lie in their mechanisms of action and clinical applications.

Which is better, ARA-290 or PE-22-28?

Neither is universally "better" - the choice depends on your specific goals. ARA-290 is typically used for cognitive purposes, while PE-22-28 is used for cognitive. Always consult with a healthcare provider to determine which may be appropriate for your situation.

Can ARA-290 and PE-22-28 be used together?

Some peptide protocols combine multiple compounds for synergistic effects. However, using ARA-290 and PE-22-28 together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.

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