COGNITIVE & NOOTROPIC / FAQ
Questions From the Literature
Citation-anchored answers to the questions readers most often bring to these three neuroactive research peptides — with the honest limits front and center.
What is Semax?
Semax is a synthetic heptapeptide derived from a fragment of the adrenocorticotropic hormone ACTH — specifically the ACTH(4-7) sequence (Met-Glu-His-Phe) — with a C-terminal Pro-Gly-Pro tripeptide added to slow enzymatic breakdown. Its full name is ACTH(4-7)PGP and its sequence is MEHFPGP. It was developed at the Institute of Molecular Genetics in Moscow and is registered as a prescription nasal spray in Russia and Ukraine for ischemic stroke, TIA, cognitive impairment, and optic-nerve disease. Outside Russia and Ukraine it is classified as an unscheduled research chemical with no approved therapeutic indication.
What is Semax peptide used for?
In Russian/Ukrainian clinical practice, Semax is used for neuroprotection in stroke and TIA, and for cognitive impairment and optic-nerve disease. In rodent research, it has been studied for neuroprotection in cerebral ischemia models, neurotrophin (BDNF/NGF) regulation [3][4], spinal cord injury recovery [1], and antiamnesic effects [5]. In the nootropic community it is used off-label and without regulatory approval for focus, mental clarity, and mood — none of which has been validated in a Western controlled clinical trial. Its use outside Russia is research-grade only.
How does Semax work?
The best-documented mechanism is rapid, region-specific upregulation of neurotrophin gene expression in the rodent brain: a single intranasal dose significantly changed BDNF and NGF mRNA in the hippocampus, brainstem and cerebellum within hours [3], and a related study found a specific, reversible, calcium-dependent brain-membrane binding site with a dissociation constant of approximately 2.4 nM along with increased BDNF protein in basal forebrain [4]. In cerebral ischemia models, a genome-wide analysis found the mechanism is dominated by immunomodulatory and vascular gene-expression shifts rather than a single receptor action [2]. Semax also inhibits enkephalin-degrading enzymes in human serum in vitro, and its monoaminergic profile — raised serotonin metabolite but only amphetamine-potentiated, not baseline, dopamine change — is more nuanced than is often presented.
What is Selank?
Selank is a synthetic heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) derived from tuftsin, an endogenous immunomodulatory tetrapeptide fragment of the IgG heavy chain. The C-terminal Pro-Gly-Pro extension slows enzymatic degradation. It was developed at the Institute of Molecular Genetics in Moscow as a non-sedating anxiolytic and is registered as a prescription drug in Russia. Outside Russia it is sold strictly as a research chemical and is not approved for human use by the FDA or EMA. It is also known as TP-7.
What does Selank do?
In a small Russian clinical trial in patients with generalized anxiety disorder, Selank produced an anxiolytic and mild activating effect comparable to a benzodiazepine comparator, without sedation, cognitive impairment, or withdrawal signs [11]. In rodent models, it has been shown to act as a positive allosteric modulator of GABA receptor binding [6], to shift GABAergic gene expression in rat frontal cortex [8], to increase BDNF expression in rat hippocampus [9], and to modulate Th1/Th2 cytokine balance in anxiety-disorder patients [10]. It also inhibits enkephalin-degrading enzymes in human plasma in vitro [12]. The human anxiolytic finding is real evidence; it has not been independently replicated in Western populations.
How does Selank work?
Two primary mechanisms are described in the literature. First, Selank acts as a positive allosteric modulator of GABA receptor binding — a subtype-selective, concentration-dependent action that differs from benzodiazepines and can block the modulatory activity of diazepam [6]. Second, it inhibits enkephalin-degrading (enkephalinase) enzymes, stabilizing endogenous enkephalins and engaging the opioid-linked anti-anxiety system [12]. It also changes GABAergic gene expression in rat frontal cortex [8], increases hippocampal BDNF [9], and modulates cytokine balance [10]. The combination with diazepam was the most effective anxiety intervention in a rat stress model [7], suggesting GABAergic synergy — and a reason for caution with human co-administration.
What is Selank peptide used for?
In Russian clinical practice, Selank is used as a prescription anxiolytic for generalized anxiety disorder and anxiety-asthenic disorders. In the nootropic community it is used without regulatory approval for situational anxiety relief, social ease, and calm focus. The human clinical evidence for the anxiety indication is a single small Russian trial [11] — real data, but not independently replicated, and not the basis for a treatment claim. Selank is not approved by the FDA or EMA for any indication, and its use outside Russia is research-grade only.
What is DSIP peptide?
DSIP — Delta Sleep-Inducing Peptide — is a naturally occurring nonapeptide (nine amino acids, sequence WAGGDASGE) first isolated from the cerebral venous blood of sleeping rabbits in 1977. Its INN is Emideltide. It is endogenously present in humans and found in cerebrospinal fluid and plasma. It is named for its reported ability to enhance slow-wave delta EEG activity when infused into animal brains. Despite decades of research, no DSIP receptor, no DSIP-encoding gene, and no precursor protein has ever been conclusively identified [14]. No Emideltide drug product has been approved or marketed by any regulator; it is sold online only as a research chemical.
What is DSIP peptide used for?
In research, DSIP has been studied primarily for sleep promotion — particularly enhancement of slow-wave (delta) sleep — and for neuroendocrine modulation, including reduction of plasma ACTH-like immunoreactivity in men [16]. Animal research has also examined longevity and stress-protection effects [15]. In community use it is taken without regulatory approval as a sleep aid. A 2006 authoritative review concluded that the sleep evidence is extremely poorly documented and still weak [14], and the largest honest signal from community experience is that a large share of users report no effect at all.
Does DSIP really work?
The honest answer is: inconsistently, and for many people, not noticeably. The 2006 Journal of Neurochemistry review — the most authoritative single summary of the DSIP literature — concluded that the link between native DSIP and sleep is extremely poorly documented, that no receptor has been identified, and that synthetic analogs (not native DSIP) drove the clearest effects [14]. A small 1981 human intravenous trial in six insomniacs found modest improvement in sleep duration and quality with no daytime sedation [17]; that is the strongest human sleep evidence in the record, and it is small and not replicated in modern controlled trials. Community experience is consistent with the literature: roughly half respond meaningfully, roughly half report nothing. Approaching DSIP with the expectation that it will reliably improve sleep is not supported by the evidence.
Are Semax, Selank and DSIP safe?
None of the three has been evaluated for long-term safety in large, rigorous human trials. Semax and Selank are registered prescription drugs in Russia, which implies some clinical safety monitoring, but that record is single-region and not subject to Western regulatory review. DSIP has no approved therapeutic history anywhere. The primary cautions are: unregulated supply (research chemicals have no guaranteed identity, purity, or sterility); unknown drug interactions (all three touch neurochemical systems also targeted by common medications); and the absence of long-term human safety data. This site does not recommend, prescribe, or advise on human use of any of these compounds.
Can Semax and Selank be combined?
Their combination is used in some nootropic communities but has not been formally studied in any controlled trial. The mechanistic concern is that both inhibit enkephalin-degrading enzymes and both modulate monoaminergic signaling, so additive effects on endogenous opioid tone and monoamine turnover are plausible. Selank also modulates the GABA system [6] and the immune cytokine axis [10], while Semax shifts neurotrophin expression and can potentiate amphetamine-evoked dopamine release. None of the interaction possibilities between these two, let alone with other medications, has been formally characterized. This desk does not advise on combinations.