Nootropic Peptides: Semax, Selank, PE-22-28, Adamax, and the Semax/Selank Mix
An overview of five cognitive peptides: Semax, Selank, PE-22-28, Adamax, and the Semax/Selank Mix. Mechanisms, research context, and product links at a glance.
Cognitive peptide research includes several distinct compound classes with different proposed mechanisms. Semax and Selank were developed in Russia and are more extensively described in the literature than PE-22-28 and Adamax. PE-22-28 and Adamax appear in a narrower preclinical context and should be described more cautiously because the published literature is more limited. This article gives an overview of the five cognitive peptides available in our catalog.
The Five Cognitive Peptides in Brief
Brain-boosting nootropic peptide derived from ACTH. Increases BDNF (brain-derived neurotrophic factor), enhances focus, memory, and mental clarity. Widely used in Russian clinical practice for cognitive enhancement.
Synthetic tuftsin analog with anxiolytic, nootropic, and immunomodulatory properties. Developed at the Russian Academy of Sciences.
Pre-mixed combination of the two leading nootropic peptides in one vial. Semax boosts focus and BDNF, Selank reduces anxiety and enhances calm. Together they provide balanced cognitive enhancement for research.
Semax - A Neurotrophic Research Peptide
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro), developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It has been described as a registered drug product in Russia.
One of the main research themes around Semax is its association with neurotrophic signaling, especially BDNF and NGF-related pathways. These pathways are relevant to synaptic plasticity, neuronal survival, and recovery models. Published work also describes broader transcriptional effects in ischemia and stress-related settings.
Broad Gene Expression Effects
Transcriptomic studies suggest that Semax can influence the expression of numerous genes, including genes linked to inflammatory and vascular responses in addition to neuronal pathways. Some studies also report downstream effects involving catecholamine and serotonin-related signaling, but these findings should be interpreted in the context of specific experimental models.
In research, Semax is most often discussed in stroke and ischemia models, cognitive and memory studies, neuroinflammation, and work on neurotrophic signaling.
Selank - An Anxiolytic Research Peptide
Selank is also a heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro), structurally derived from Tuftsin, a naturally occurring immunomodulatory fragment. Like Semax, it was developed at the same institute and has been described as a registered drug product in Russia.
Selank is mainly discussed in the literature in connection with anxiolytic and stress-related research. GABA-related signaling is one recurring hypothesis, but the mechanistic picture is still narrower and less settled than the label "GABA peptide" would suggest.
Some publications also discuss possible effects on endogenous opioid peptide systems and immune signaling, including cytokine-related pathways. These points are better treated as proposed or context-dependent mechanisms rather than as firmly established primary actions.
Claims about broad monoamine effects should also be stated cautiously. Depending on the model, downstream changes involving additional neurotransmitter systems may be reported, but these findings are better described as model-dependent than as a single established primary mechanism.
Typical research fields include anxiety and stress models, GABAergic modulation, immunomodulation, and cognition under stress conditions.
Semax and Selank Mix - Combined Exposure in One Vial
The Semax/Selank Mix combines both peptides in one vial. In research terms, the rationale is straightforward: Semax and Selank are often discussed as complementary compounds because they are linked to different signaling profiles.
In practice, this allows researchers to examine Semax-associated neurotrophic signaling alongside the anxiolytic and stress-related research literature around Selank. The mixture should not be framed as a superior nootropic format; it is better understood as a convenience product for protocols that want to evaluate both peptides together.
Simplified Research Protocol
For projects that plan to examine both compounds in the same protocol, the mix can reduce separate handling and preparation steps.
View Semax/Selank Mix in the shop
PE-22-28 - A Different Approach via TREK-1
PE-22-28 belongs to the Spadin family and is mechanistically distinct from Semax and Selank. Its main research association is the TREK-1 potassium channel (TWIK-Related K+ Channel 1), a two-pore channel expressed in the central nervous system.
TREK-1 is studied because animal models link reduced TREK-1 activity to antidepressant-like effects. That makes TREK-1 inhibition a relevant area in preclinical mood-disorder research.
PE-22-28 is discussed as a TREK-1-modulating peptide in animal models, with reported effects on neuronal excitability and hippocampal neurogenesis. Some authors connect this line of research to serotonergic activity, but for PE-22-28 it is more precise to describe TREK-1 modulation as the central mechanism and treat serotonin-related changes as downstream or model-dependent findings.
Preclinical Time-Course Data
Compared with classical SSRIs, Spadin-family peptides have been studied for shorter time-to-effect signals in animal models of antidepressant-like activity. This is one reason PE-22-28 remains relevant in exploratory preclinical work.
Research fields include TREK-1 pharmacology, antidepressant research with novel mechanisms, hippocampal neurogenesis, and cognitive effects of potassium channel modulation.
Adamax - A Semax-Related Peptide with Limited Literature
Adamax is structurally related to Semax, but the published literature on it is much thinner. Because of that, strong comparative claims should be avoided unless a specific primary source supports them.
Adamax is usually presented as a Semax-related analog for comparative research. It may be relevant for exploratory work on structure-activity relationships, formulation questions, or side-by-side evaluation against Semax, but the evidence base is not strong enough to describe it as clearly more stable, more potent, or more active on BDNF, NGF, or dopamine pathways.
Adamax fits best into a cautious research context: comparative peptide studies and hypothesis-generating work rather than well-established mechanism claims.
Orientation: Which Peptide Suits Which Research Goal?
Neurotransmitter Profiles Compared
Semax is most often discussed in connection with neurotrophic signaling and broader transcriptional effects. Selank is more often discussed in anxiolytic and stress-related research, with GABA-related signaling treated as one proposed mechanism among several. PE-22-28 is primarily relevant to TREK-1 modulation. Adamax is mainly a Semax-related comparison compound because the mechanistic literature is limited.
Quality and Shipping
All cognitive peptides at PeptidesDirect are delivered with independent purity testing (Janoshik COA, at least 98%). Shipping is within the EU in 2-3 business days, without customs. Payment is accepted via crypto or credit card. For reconstitution, we carry Bacteriostatic Water.
Storage
All peptides are delivered lyophilized. Before reconstitution, storage in a freezer is generally preferred for longer-term stability. After reconstitution, refrigerated storage is commonly recommended, but the exact temperature range and usable timeframe depend on the peptide, solvent, concentration, and handling conditions. Observe light protection where relevant. More details in the Peptide Storage Guide.