Selank vs PE-22-28
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: Selanc, TP-7
Selank is a synthetic seven-amino-acid peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) built from the natural immune peptide tuftsin, with a small chemical tweak to make it last longer in the body. It was developed in Russia as an anti-anxiety and nootropic agent and is approved there for generalized anxiety disorder, but it has no FDA or EMA approval and almost no Western clinical data. The pitch is calm and focus without the sedation, dependence, or withdrawal that come with benzodiazepines.
Also: PE22-28, Spadin Analog
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.
Key Comparison Insights
- Both peptides belong to the Cognitive category, suggesting similar primary applications.
- Selank has stronger research evidence (Human Trials) compared to PE-22-28 (Animal Studies).
Detailed Comparison
| Attribute | Selank | PE-22-28 |
|---|---|---|
| Category | Cognitive | Cognitive |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Selank seems to work through several overlapping systems rather than one tidy target. It influences GABA signaling, the brain's main calming neurotransmitter system, which likely accounts for its anti-anxiety effect. It also slows the breakdown of enkephalins, the body's own opioid-like peptides involved in mood and stress, which is a mechanism entirely different from benzodiazepines or SSRIs. Animal work additionally points to effects on serotonin and dopamine balance and on BDNF, a growth factor tied to learning and neuron health. These pathways are well documented in rodents; the picture in humans is inferred rather than directly measured. | 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 | 250-500 mcg intranasal 2-3x daily 2-3x daily, intranasal | 100-300 mcg intranasal or subcutaneous Once daily |
| Administration | Intranasal spray (most common), subcutaneous injection | Intranasal or subcutaneous injection |
| Typical Duration | 14-21 days typical | Research protocols vary, often 2-4 weeks |
| Best Time to Take | Morning or as needed for anxiety | Morning |
Possible Side Effects May vary by individual |
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| Research Summary | Most of the rigorous data is preclinical and Russian. In rodents, Selank shows consistent anxiety-reducing and mild cognitive effects, and one PMC-indexed study found it enhanced diazepam's anti-anxiety effect under chronic stress. The main human clinical reference is a Russian comparative trial by Zozulia, Neznamov, and colleagues in patients with generalized anxiety disorder and neurasthenia, reporting that Selank's anxiolytic effect was comparable to the benzodiazepine medazepam on standard rating scales, with added anti-fatigue benefits and changes in enkephalin activity. The honest caveat: that trial was relatively small, the published English abstract gives qualitative results rather than hard effect sizes and p-values, and it has not been replicated by independent Western groups. So the evidence supports a real but modestly studied anxiolytic, mostly validated within the regulatory system that approved it. | 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: Selank vs PE-22-28
What is the difference between Selank and PE-22-28?
Selank is a cognitive peptide that selank is a synthetic seven-amino-acid peptide (thr-lys-pro-arg-pro-gly-pro) built from the natural immune peptide tuftsin, with a small chemical tweak to make it last longer in the body. it was developed in russia as an anti-anxiety and nootropic agent and is approved there for generalized anxiety disorder, but it has no fda or ema approval and almost no western clinical data. the pitch is calm and focus without the sedation, dependence, or withdrawal that come with benzodiazepines. 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, Selank or PE-22-28?
Neither is universally "better" - the choice depends on your specific goals. Selank 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 Selank and PE-22-28 be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Selank 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.