塞兰克肽 Selank

Selank is a synthetic 7-amino-acid peptide that produces anxiolytic and nootropic effects through the GABA system — but without the dependence, sedation, or memory impairment that come with benzodiazepines. That combination is what makes it interesting to researchers and clinicians alike.

It's derived from tuftsin, an endogenous tetrapeptide (Thr-Lys-Pro-Arg) with immunomodulatory properties. Selank's full sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro — three additional amino acids added to extend its stability and biological activity.^[3] Russian researchers at the Institute of Molecular Genetics developed it specifically to capture tuftsin's neuroimmune effects while adding anxiolytic and cognitive-enhancing properties.

In Russia, Selank is approved and used clinically as an anxiolytic. In the United States, it has no FDA approval and is classified as research-use only. That gap between its clinical use elsewhere and its regulatory status here is the central tension anyone researching this compound will run into.

• Selank is a synthetic heptapeptide anxiolytic that works through the GABA system without producing dependence, tolerance, or sedation — the key liabilities of benzodiazepines.
• Preclinical evidence shows meaningful anxiolytic effects comparable to diazepam at 0.3 mg/kg in rat models, plus protective effects on memory and BDNF levels during alcohol withdrawal.

There are no published randomized clinical trials establishing an official dose for Selank in humans. The 0.3 mg/kg intraperitoneal dose used across multiple rat studies^[1][2][4] is a consistent reference point in the animal literature, but translating that directly to human dosing involves extrapolation that hasn't been validated in controlled human trials.

Not clinical dosing data

The dose ranges below are not derived from randomized clinical trials in humans. They reflect practitioner consensus and community-reported use. Dosing should be discussed with a licensed healthcare provider familiar with this compound. Do not self-administer based on this information alone.

In practitioner settings where Selank is used, intranasal administration is the most commonly reported route, typically at 250–500 mcg per dose, administered once or twice daily — though Selank dosing and administration routes have not been established in human clinical trials; available evidence is limited to animal studies. Subcutaneous injection is also reported, with similar dose ranges, though again, Selank dosing and administration routes have not been established in human clinical trials; available evidence is limited to animal studies. The intranasal route is preferred by many practitioners because Selank crosses the blood-brain barrier more efficiently via nasal mucosa than through systemic injection, though Selank dosing and administration routes have not been established in human clinical trials; available evidence is limited to animal studies.

The 0.3 mg/kg animal dose that produced a 39.6% reduction in morphine withdrawal index^[1] and eliminated alcohol withdrawal anxiety^[4] is the most rigorously documented reference point in the literature. Until human RCT data exists, all human dosing guidance carries meaningful uncertainty.

Most anxiolytics work by suppressing the nervous system broadly. Benzodiazepines enhance GABA-A receptor activity so aggressively that tolerance develops within weeks, withdrawal can be severe, and cognitive impairment is essentially guaranteed at therapeutic doses. That's a significant tradeoff for someone using them long-term.

Selank appears to modulate the same GABAergic system, but with a much lighter touch — and without the downstream consequences that make benzodiazepines problematic for chronic use.

The key finding from the diazepam comparison study

In unpredictable chronic mild stress conditions, Selank's anxiolytic effect was comparable to diazepam. When the two were combined, the effect was enhanced — suggesting they act through overlapping but not identical mechanisms. Selank appeared to potentiate diazepam's activity rather than simply duplicate it.^[2]

The other distinguishing feature is the nootropic component. Most anxiolytics impair memory and attention — that's not a side effect, it's pharmacologically expected when you suppress GABAergic tone broadly. Selank does the opposite. In rats exposed to chronic ethanol, Selank at 0.3 mg/kg for 7 days not only prevented ethanol-induced memory impairment but produced a cognitive-stimulating effect even in unexposed animals.^[2] That effect correlated with preserved BDNF (brain-derived neurotrophic factor) levels in the hippocampus and prefrontal cortex — two regions central to memory consolidation and executive function.

That combination — anxiolytic without sedation, cognitive protection without impairment — is genuinely uncommon in the pharmacology of anxiety treatment.

Selank's mechanism operates on two overlapping levels: direct modulation of GABA transmission and regulation of gene expression linked to neuropeptide signaling.^[3]

The GABA system is the brain's primary inhibitory signaling network. When it's underactive, anxiety follows. Benzodiazepines force GABA-A receptors into a hyperactive state — effective, but blunt. Selank appears to modulate GABAergic tone more selectively, producing anxiolytic effects without the receptor downregulation that drives tolerance and dependence.^[3]

The BDNF connection matters separately. BDNF is a protein that supports neuron survival, promotes synaptic plasticity, and plays a central role in learning and memory. Chronic stress and alcohol exposure both deplete BDNF in the hippocampus — which is one reason prolonged anxiety and alcohol use damage memory. Selank's ability to preserve hippocampal and prefrontal BDNF levels in alcohol-exposed rats^[2] suggests a neuroprotective mechanism that operates independently of its acute anxiolytic effect.

Its origin as a tuftsin analog also gives it an immunomodulatory dimension. Tuftsin itself activates macrophages and natural killer cells and influences cytokine signaling. Selank retains some of this activity, which is why neuroimmune modulation appears among its documented effects — though the human relevance of this pathway remains less characterized than its CNS effects.^[3]

The peptide's short 7-amino-acid structure (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is stable enough to reach target tissues but metabolizes relatively quickly, which may explain why its effects are described as anxiolytic without prolonged sedation.^[3]

The honest summary: the evidence base for Selank is almost entirely preclinical. The published studies are consistent and mechanistically coherent, but they're rat studies. Extrapolating to humans requires caution.

Anxiety and withdrawal — morphine model: A 2022 study administered Selank at 0.3 mg/kg intraperitoneally to naloxone-precipitated morphine-dependent rats.^[1] A single injection reduced the total morphine withdrawal index by 39.6%, significantly attenuated convulsive reactions and ptosis, and increased tactile sensitivity threshold 9-fold compared to active control. The effect was slightly inferior to diazepam at 2 mg/kg — but Selank produced these results without diazepam's sedative and dependence liabilities.

Memory protection — ethanol model: In rats given 10% ethanol as their only fluid source for 30 weeks, Selank at 0.3 mg/kg daily for 7 days prevented the formation of ethanol-induced memory and attention disturbances during withdrawal.^[2] It also produced a cognitive-stimulating effect in unexposed animals. The mechanism appears to involve preservation of BDNF in the hippocampus and prefrontal cortex, both of which were depleted in ethanol-exposed controls.

Diazepam potentiation: Under unpredictable chronic mild stress conditions, Selank's anxiolytic effect was comparable to diazepam in the elevated plus maze test. Combined administration enhanced the effect of both compounds, suggesting a synergistic or additive interaction.^[4] Even without chronic stress, Selank showed anxiolytic activity at standard doses.

Alcohol withdrawal anxiety: In alcohol-preferring rats (mean daily ethanol intake >5.0 g/kg), a single 0.3 mg/kg injection of Selank eliminated withdrawal-induced anxiety in elevated plus maze and social interaction tests, and prevented mechanical allodynia, without affecting ethanol consumption itself.^[4][5]

What the Evidence Does Not Show

• Human RCT data — No large-scale randomized controlled trials in humans have been published in English-language peer-reviewed literature. Russian clinical literature exists but is not consistently accessible or independently replicated.
• Long-term safety in humans — Animal studies show a favorable short-term profile, but there is no published data on what happens with months or years of human use.
• Dose-response in humans — The 0.3 mg/kg animal dose is a consistent reference point, but human pharmacokinetics differ substantially. No published trial has established an optimal human dose range.
• Comparison to modern anxiolytics — There are no head-to-head trials against SSRIs, SNRIs, buspirone, or other commonly prescribed anxiolytics. The diazepam comparison exists only in animal models.
• Cognitive enhancement in healthy humans — The nootropic effects observed in rats are compelling, but whether they translate to meaningful cognitive improvement in healthy humans has not been tested in controlled conditions.

Human side effect data for Selank is genuinely limited. What's known comes primarily from animal studies and practitioner-reported observations, not clinical trial adverse event reporting.

From animal studies:

• Dependence and tolerance — Not observed at anxiolytic doses in preclinical models. This is the most important distinction from benzodiazepines and the most consistently reported finding across studies.^[3]
• Sedation — Not a prominent feature at the 0.3 mg/kg dose used in research. The anxiolytic effect appears dissociable from sedation.
• Memory impairment — Not observed; the opposite was found in the ethanol memory model.^[2]

From practitioner and community reports (not clinical trial data):

• Nasal irritation — Nasal irritation has been reported in some contexts with intranasal administration, but human safety data are not established; effects in humans remain unstudied.
• Mild fatigue or sedation — Occasionally reported at higher doses; effects in humans have not been established, and animal studies do not provide reliable data on adverse effects at doses relevant to human use.
• Injection site reactions — Mild redness or discomfort with subcutaneous administration; injection site reactions have not been documented in available human studies, and animal studies do not typically assess local injection site responses comparable to clinical observations.

The absence of serious adverse events in the published animal literature is notable, but it doesn't substitute for human safety data. If you're considering Selank under medical supervision, the honest answer is that the risk profile looks favorable in preclinical work, but the human safety database is thin. Work with a provider who will monitor you.

US regulatory status — research use only

Selank is not FDA-approved for any indication in the United States. It is classified as research-use only. It is not available through licensed US compounding pharmacies as a prescription product and has no approved commercial pathway in the US market. Access outside of formal research settings exists through gray-market research chemical vendors, which carries its own set of quality and legal considerations.

In Russia, Selank is an approved prescription anxiolytic developed by the Institute of Molecular Genetics of the Russian Academy of Sciences. It's been used clinically there for anxiety and cognitive support. That approval does not confer any legal status in the United States.

For US patients and providers: Selank occupies the same regulatory space as many research peptides — technically legal to possess for research purposes, not legal to prescribe or administer as a treatment. The practical reality is that it circulates through research chemical vendors, and some practitioners in the functional medicine and peptide therapy space use it off-label. That use happens outside any formal regulatory framework.

If you're sourcing Selank through research chemical channels — which is the only realistic access pathway in the US — quality control is the central concern. Peptide synthesis quality varies enormously across vendors, and a compound acting on your GABA system and BDNF pathways deserves more scrutiny than a supplement.

What to look for:

• Third-party Certificate of Analysis (COA) — Must be from an independent laboratory, not the vendor's own testing. Look for the lab name, date, and the specific batch number on the COA.
• HPLC purity report — Minimum 98% purity for a research peptide. Mass spectrometry confirmation of the correct molecular weight is a stronger guarantee than HPLC alone.
• Correct amino acid sequence verification — Selank's sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro. A reputable vendor can provide sequence confirmation.
• Sterile, lyophilized powder — Should arrive as a white lyophilized powder in a sealed vial, reconstituted with bacteriostatic water before use.

Red flags:

• No COA or "in-house testing only" — The most common indicator of a low-quality vendor. Independent testing costs money; vendors who skip it are cutting corners.
• Price significantly below market — Peptide synthesis and quality testing have real costs. Unusually cheap product usually means compromised purity or incorrect sequence.
• Pre-mixed or liquid formulation — Peptides in solution degrade faster and are harder to verify for purity and concentration. Lyophilized powder is the standard.
• No information about storage or reconstitution — A vendor who can't explain basic handling requirements doesn't understand what they're selling.

If Selank's anxiolytic and nootropic profile interests you, Semax is the most natural comparison — another Russian-developed neuropeptide with overlapping but distinct effects, and a similarly thin US clinical evidence base. For anxiety specifically, BPC-157 is sometimes discussed in practitioner circles for its effects on stress response and gut-brain signaling, though through entirely different mechanisms.

Selank vs. Related Research Peptides