PE-22-28 vs NA-Semax Amidate
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
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.
Also: N-Acetyl Semax Amidate, NA-Semax
NA-Semax Amidate is the stabilized form of Semax, the Russian nootropic peptide derived from a fragment of ACTH. Same modification logic as the Selank variant: acetyl group at one end, amide at the other, both there to stop enzymes chewing it up before it does anything. It is the most widely used Semax variant in Western nootropic circles, largely on the strength of that stability argument.
Key Comparison Insights
- Both peptides belong to the Cognitive category, suggesting similar primary applications.
- NA-Semax Amidate has stronger research evidence (Human Trials) compared to PE-22-28 (Animal Studies).
Detailed Comparison
| Attribute | PE-22-28 | NA-Semax Amidate |
|---|---|---|
| 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 | 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. | Semax is a synthetic analog of ACTH (4-10), a fragment of adrenocorticotropic hormone that has been stripped of hormonal activity while retaining effects on the brain. Its best-characterized action is a marked increase in BDNF and NGF expression in the hippocampus, which is the mechanistic basis for the memory and neuroprotection claims. It also modulates dopaminergic and serotonergic transmission, and affects the melanocortin system, which is thought to contribute to its effects on attention and motivation. Notably it does this without the HPA axis activation you would expect from something derived from ACTH, because the fragment lacks the region responsible for that. The acetylation and amidation slow degradation by peptidases, so more of the dose survives to act. |
| Common Dosing | 100-300 mcg intranasal or subcutaneous Once daily | 300-600 mcg daily (intranasal) Once or twice daily, morning and early afternoon |
| Administration | Intranasal or subcutaneous injection | Intranasal is the standard and best-supported route, since it was developed as a nasal formulation |
| Typical Duration | Research protocols vary, often 2-4 weeks | Community protocols commonly report 2-4 week blocks |
| Best Time to Take | Morning | Morning, or morning and early afternoon if split |
Possible Side Effects May vary by individual |
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| Research Summary | 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. | Semax has a genuine and reasonably large research base, concentrated in Russia, where it is a registered medicine used for ischemic stroke, cognitive impairment and optic nerve disorders. Animal work consistently supports the BDNF and NGF upregulation, and there is human clinical work in stroke recovery. The important caveat is the same as for Selank: this literature is largely Russian, much of it predates modern trial standards, replication in large Western randomized trials has not happened, and neither the FDA nor the EMA has assessed it. For the amidate variant specifically there is no independent published pharmacology comparing it to standard Semax in humans. The stability modification is chemically sound and widely used, and the assumption that it improves real-world effect is reasonable but unproven. |
Frequently Asked Questions: PE-22-28 vs NA-Semax Amidate
What is the difference between PE-22-28 and NA-Semax Amidate?
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. NA-Semax Amidate is a cognitive peptide that na-semax amidate is the stabilized form of semax, the russian nootropic peptide derived from a fragment of acth. same modification logic as the selank variant: acetyl group at one end, amide at the other, both there to stop enzymes chewing it up before it does anything. it is the most widely used semax variant in western nootropic circles, largely on the strength of that stability argument. The main differences lie in their mechanisms of action and clinical applications.
Which is better, PE-22-28 or NA-Semax Amidate?
Neither is universally "better" - the choice depends on your specific goals. PE-22-28 is typically used for cognitive purposes, while NA-Semax Amidate is used for cognitive. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can PE-22-28 and NA-Semax Amidate be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using PE-22-28 and NA-Semax Amidate 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.