Pinealon/PE-22-28/Selank: The Complete Guide to the Neuroprotective Blend

Why This Combination Exists

Brain health is not one problem. It is three problems that people experience as one. Sleep deteriorates, and without deep restorative sleep the brain cannot clear metabolic waste or consolidate memory. Neural connections weaken, and without active neurogenesis the brain loses the plasticity it needs to adapt and recover. Anxiety escalates, and chronic stress signaling damages the same neural circuits that sleep and neurogenesis are supposed to maintain. Each problem feeds the other two.

Most interventions only address one layer. Sleep medications sedate but don't restore natural circadian architecture. SSRIs modulate serotonin but take weeks to work and come with side effects. Nootropics sharpen cognition acutely but don't repair underlying neural infrastructure. The brain needs all three layers working simultaneously: restorative sleep to clear and consolidate, active neurogenesis to build and repair, and regulated anxiety signaling to stop the damage cascade.

This blend targets each layer through an independent mechanism. Pinealon is a tripeptide bioregulator that supports melatonin synthesis and circadian rhythm regulation in the pineal gland. PE-22-28 is a heptapeptide that blocks the TREK-1 potassium channel to promote neurogenesis and synaptic plasticity. Selank is a tuftsin analog that modulates GABA allosterically to reduce anxiety without sedation, dependence, or cognitive fog. Three peptides, three receptors, three outcomes that reinforce each other.

Three Labs, Three Discoveries

Pinealon came from four decades of bioregulator research in St. Petersburg. Vladimir Khavinson at the Institute of Bioregulation and Gerontology originally isolated the tripeptide (Glu-Asp-Arg) from Cortexin, a neuroprotective polypeptide complex derived from bovine brain tissue. Unlike conventional peptides that work through cell surface receptors, Khavinson's group showed that Pinealon appears to interact directly with DNA. Molecular modeling and docking studies found that the EDR tripeptide binds to hexanucleotide sequences commonly found in promoter regions of genes including CASP3, SOD2, NES, GAP43, and APOE, all of which are implicated in neuronal survival, antioxidant defense, and Alzheimer's pathology.

In cell culture studies, Pinealon showed dose-dependent suppression of reactive oxygen species in cerebellar granule cells and PC12 cells, modulated caspase-3 to inhibit apoptosis under hypoxic conditions, and supported expression of tryptophan hydroxylase (the rate-limiting enzyme for serotonin synthesis). In a 2021 Alzheimer's mouse model study, EDR peptide prevented dendritic spine loss in 5xFAD-M mice through the MAPK/ERK signaling pathway. The most striking clinical signal came from a study of 72 patients with traumatic brain injury consequences and cerebrasthenia: oral Pinealon (0.2 mg twice daily for 20-30 days) alongside standard therapy improved memory, reduced headache duration and intensity, stabilized emotional regulation, and improved information processing speed on proof-correction testing.

PE-22-28 came from a breakthrough in French neuroscience that started with a genetic observation. In 2006, Heurteaux and colleagues published a landmark paper in Nature Neuroscience showing that mice lacking the TREK-1 gene (a two-pore potassium channel expressed in the prefrontal cortex, amygdala, and hippocampus) were resistant to depression across five different behavioral models. These knockout mice behaved like animals on chronic fluoxetine. They also showed increased serotonin neurotransmission and reduced stress-induced corticosterone. The implication was clear: block TREK-1 pharmacologically and you might replicate the antidepressant effect.

The first blocker came from an unexpected source. Spadin, a 44-amino-acid peptide released during the post-translational maturation of sortilin (neurotensin receptor-3) in the Golgi apparatus, naturally inhibited TREK-1. But Spadin degraded in blood within hours. In 2017, Djillani, Mazella, and colleagues studied Spadin's blood degradation fragments and designed shortened analogs. PE-22-28, a seven-amino-acid fragment, showed dramatically better TREK-1 inhibition than its parent compound (IC50 of approximately 0.12 nM versus 40-60 nM for Spadin), improved blood plasma stability, and antidepressant-like activity that lasted over 23 hours versus 7 for Spadin. Critically, PE-22-28 was selective for TREK-1 and did not significantly inhibit the related channels TREK-2 or TRAAK. It also induced hippocampal neurogenesis after just 4 days of treatment and enhanced synaptogenesis measured by PSD-95 expression in cortical neurons.

Selank came from Soviet immunology, repurposed for neuroscience. In the 1970s, researchers at the Institute of Molecular Genetics in Moscow were studying tuftsin, a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) found in the heavy chain of human immunoglobulin G. Tuftsin modulates immune function. The research group added three amino acids (Pro-Gly-Pro) to the C-terminus to improve metabolic stability and created Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro). The anxiolytic effects were unexpected. Selank modulates GABA allosterically, enhancing the brain's natural inhibitory signaling without the direct receptor binding that makes benzodiazepines sedating and addictive. It also influences serotonin and dopamine metabolism, elevates BDNF mRNA in the hippocampus and prefrontal cortex, inhibits enzymes that degrade enkephalins (prolonging the body's endogenous calming signals), and normalizes pro-inflammatory cytokines including IL-6 and TNF-alpha. In a clinical trial of 62 patients with generalized anxiety disorder, Selank showed anxiolytic efficacy comparable to medazepam (a benzodiazepine) while also producing antiasthenic and psychostimulant effects that the benzo did not. It became a registered prescription medication in Russia in 2009. Read the full Selank/Semax guide for the complete history.

Russian gerontology, French neuropharmacology, Soviet immunology. Three research traditions that never coordinated. But each discovered a peptide that addresses a different bottleneck in brain health. Pinealon protects and regulates. PE-22-28 builds and grows. Selank calms and stabilizes. The combination covers all three.

What Each Peptide Brings

The three peptides create a reinforcing cycle. Pinealon restores sleep architecture, and deep sleep is when the brain clears amyloid beta, consolidates memory, and performs synaptic maintenance. PE-22-28 drives neurogenesis, producing new neurons and synaptic connections that are then consolidated during the deep sleep Pinealon supports. Selank reduces the chronic anxiety signaling that actively damages hippocampal neurons and suppresses both sleep quality and neurogenesis. Remove any one layer and the other two underperform.

Key Research

Each peptide has an independent evidence base. Selank has the strongest clinical data including human trials and a regulatory approval. PE-22-28 has strong preclinical mechanistic evidence. Pinealon has in vitro and animal model data from the Russian bioregulator research tradition. No study has tested the three-peptide combination together.

TREK-1 and PE-22-28 evidence

Heurteaux C et al. "Deletion of the background potassium channel TREK-1 results in a depression-resistant phenotype." Nature Neuroscience, 2006. View study

Published in Nature Neuroscience. The foundational study that identified TREK-1 as a depression target. Heurteaux showed that TREK-1 knockout mice were resistant to depression across five behavioral models (forced swim, tail suspension, conditioned suppression, learned helplessness, novelty-suppressed feeding). The knockout mice had increased serotonin neurotransmission and reduced stress-induced corticosterone. This paper established the scientific rationale for pharmacological TREK-1 blockade.

Djillani A et al. "Shortened Spadin Analogs Display Better TREK-1 Inhibition, In Vivo Stability and Antidepressant Activity." Frontiers in Pharmacology, 2017. View study

The defining paper for PE-22-28. Djillani and Mazella's group designed shortened analogs from Spadin's blood degradation fragments. PE-22-28 showed an IC50 of approximately 0.12 nM for TREK-1 inhibition (roughly 300-500x more potent than Spadin), was selective for TREK-1 over related channels TREK-2 and TRAAK, and produced antidepressant-like activity lasting over 23 hours (versus 7 for Spadin). The compound also induced hippocampal neurogenesis after just 4 days of treatment and enhanced synaptogenesis (PSD-95 expression) in cortical neurons.

Selank evidence

Zozulya AA et al. "Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia." Zhurnal Nevrologii i Psikhiatrii, 2008. View study

Clinical trial: 30 patients received Selank, 32 received medazepam (a benzodiazepine). Both groups were assessed with Hamilton, Zung, and CGI psychometric scales. Anxiolytic effects were comparable, but Selank also produced antiasthenic and psychostimulant effects that medazepam did not. The study also measured enkephalin activity in blood serum, finding that patients with GAD had decreased tau-leu-enkephalin levels correlated with symptom severity, and Selank modulated these levels. This was part of the evidence base for Selank's 2009 Russian prescription approval.

Kasian A et al. "Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission." Frontiers in Pharmacology, 2016. View study

Demonstrated the molecular mechanism behind Selank's anxiolytic effects. The peptide modulates expression of genes involved in GABA neurotransmission, providing the mechanistic link between Selank administration and clinically observed anxiety reduction. The allosteric GABA modulation (rather than direct receptor binding) explains why Selank achieves benzodiazepine-comparable effects without sedation, tolerance, or dependence.

Pinealon evidence

Khavinson VK et al. "EDR Peptide: Possible Mechanism of Gene Expression and Protein Synthesis Regulation Involved in the Pathogenesis of Alzheimer's Disease." Molecules, 2021. View study

Molecular docking studies showed that the EDR tripeptide binds to hexanucleotide sequences in promoter regions of genes involved in Alzheimer's pathology: CASP3 (apoptosis), SOD2 (antioxidant defense), NES and GAP43 (neuroplasticity), APOE (lipid metabolism). In a companion mouse model study (5xFAD-M mice), EDR prevented dendritic spine loss through the MAPK/ERK signaling pathway. This paper established the proposed mechanism: Pinealon interacts directly with DNA to regulate gene expression patterns, rather than working through conventional cell surface receptors.

Khavinson VK et al. "Pinealon Increases Cell Viability by Suppression of Free Radical Levels and Activating Proliferative Processes." Rejuvenation Research, 2011. View study

Demonstrated dose-dependent suppression of reactive oxygen species in cerebellar granule cells, neutrophils, and PC12 cells under oxidative stress conditions. Also showed a clinical signal: oral Pinealon (0.2 mg twice daily for 20-30 days) in 72 patients with traumatic brain injury consequences improved memory, reduced headache duration and intensity, and increased information processing speed versus standard therapy alone. This is the closest to human clinical evidence for Pinealon, though the study was not a large-scale RCT.

On the combination

No study has tested Pinealon, PE-22-28, and Selank together. The combination rationale is based on non-overlapping mechanisms: Pinealon targets pineal gland function and neuroprotection, PE-22-28 targets the TREK-1 channel for neurogenesis, and Selank targets GABA and neuroimmune pathways for anxiety reduction. Each peptide works through a different receptor system, reducing the likelihood of interference and supporting the case for complementary effects. The logic is sound. The specific triple combination has not been independently validated.

When to Expect Results

The three peptides operate on different timescales. Selank's anxiolytic effects are the fastest because GABA modulation produces acute neurochemical changes. Pinealon's sleep effects develop over days to weeks as circadian regulation normalizes. PE-22-28's neurogenesis effects are the slowest because growing new neurons and forming new synaptic connections takes time.

The Honest Truth

This blend combines three peptides with complementary mechanisms for brain health. The rationale is sound and the individual evidence profiles are interesting. But the limitations are real.

Pinealon evidence is primarily preclinical and Russian-sourced. The bioregulator research tradition has produced interesting in vitro and animal data, but it has not been widely replicated by independent Western laboratories. No large-scale human clinical trial has tested Pinealon for sleep or neuroprotection. The mechanistic evidence (caspase-3 modulation, oxidative stress reduction, tryptophan hydroxylase expression) is plausible but has not been validated in controlled human studies.

PE-22-28 is preclinical only. The Frontiers in Pharmacology paper is well-conducted and the TREK-1 mechanism is well-characterized. But all data is from mouse models and cell cultures. No human has been tested with PE-22-28 in a clinical trial. The IC50 data is impressive, but translating preclinical potency to human outcomes is not guaranteed. TREK-1 blockade as an antidepressant strategy is scientifically grounded (TREK-1 knockout mice are depression-resistant), but the clinical translation is incomplete.

Selank has the strongest evidence but limited international validation. The 62-patient clinical trial and the Russian regulatory approval are meaningful. But the clinical data comes primarily from Russian institutions, and large-scale international replication studies have not been conducted. The drug-interaction profile has not been extensively studied, particularly in combination with Western psychiatric medications.

No FDA approvals. Selank is a registered prescription medication in Russia. None of the three peptides are FDA-approved in the United States. All are available through compounding pharmacies with a provider prescription. This is standard for the peptide therapy space but worth understanding clearly.

Psychiatric medication interactions are not well-studied. If you are taking benzodiazepines, SSRIs, SNRIs, MAOIs, or other psychoactive medications, discuss this blend with your prescribing physician before starting. Selank may potentiate benzodiazepine effects. PE-22-28's influence on neuronal excitability could theoretically interact with medications that affect seizure threshold. This is not a replacement for psychiatric medication. It is a supplement that requires provider oversight.

Blend vs Alternatives

How does this compare to the individual components and the Selank/Semax blend?

Protocol

PeRx ships Pinealon/PE-22-28/Selank as a single pre-mixed vial containing all three peptides at calibrated concentrations. No reconstitution, no drawing from multiple vials, no mixing. One vial, one injection.

Why evening timing matters

Melatonin synthesis in the pineal gland naturally ramps up in the evening as light exposure decreases. Pinealon supports this process, so injecting during the natural melatonin window amplifies the effect. Selank's anxiolytic action helps quiet the mental activity that prevents sleep onset. And the neurogenesis PE-22-28 promotes is consolidated during slow-wave sleep, meaning the work it starts is completed while you sleep.

Some users prefer morning dosing for the cognitive clarity and anxiety reduction benefits during the workday. This is a reasonable alternative. Discuss timing preference with your provider based on whether your primary goal is sleep restoration or daytime cognitive performance.

Why cycling matters

Receptor systems adapt to sustained stimulation. GABA receptor modulation, TREK-1 channel dynamics, and pineal gland responsiveness all require periodic breaks to maintain sensitivity. An 8-12 week cycle followed by 4 weeks off allows these systems to normalize. Many users find that benefits partially persist during the washout period, particularly sleep improvements and baseline anxiety reduction.

Who This Is For

Frequently Asked Questions