# Adalank — Research Peptide Profile

> Adalank (N-acetyl Selank amidate) has no published studies of its own. The Selank clinical evidence it borrows from, and the gaps that remain.

Source: https://peptpedia.org/peptide/adalank | Published: 2026-09-18 | Last updated: 2026-09-18

Adalank is the N-acetyl, C-amidated form of Selank, the tuftsin-derived heptapeptide approved as an anxiolytic in Russia. The two end caps are standard medicinal-chemistry modifications intended to resist protease degradation, but Adalank itself has never appeared in a peer-reviewed study. Everything claimed for it derives from Selank, which has small Russian clinical trials in anxiety disorders but no Western regulatory review.

## Overview

Adalank is a research-chemical modification of [Selank](/peptide/selank) (Thr-Lys-Pro-Arg-Pro-Gly-Pro), the synthetic tuftsin analog developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and registered in Russia as an anxiolytic. The name describes the structure exactly: the Selank sequence with an acetyl group capping the N-terminus and an amide capping the C-terminus. These are the two most common end-cap modifications in peptide medicinal chemistry, intended to block aminopeptidase and carboxypeptidase attack and thereby extend functional half-life. The molecular formula calculated for this defined structure (C35H60N12O9, 792.9 g/mol) matches vendor specifications, but no PubChem record and no peer-reviewed study exists for the conjugate. The evidence base is therefore entirely that of parent Selank: small Russian clinical trials in generalized anxiety disorder and neurasthenia, fMRI studies in healthy volunteers, and rodent work on BDNF, GABAergic gene expression, and enkephalin metabolism.

## Molecular Profile

- **Category:** cognitive-enhancement
- **Molecular formula:** C35H60N12O9 (calculated for Ac-Thr-Lys-Pro-Arg-Pro-Gly-Pro-NH2; not independently published)
- **Molecular weight:** 792.9 g/mol (calculated)
- **Amino acid sequence:** Ac-Thr-Lys-Pro-Arg-Pro-Gly-Pro-NH2
- **Also known as:** N-Acetyl Selank Amidate, NA-Selank-Amidate, Acetyl Selank Amidate
- **Half-life:** Not measured for Adalank; unmodified Selank clears plasma within minutes while effects persist for hours
- **Solubility:** Not formally documented; expected water-soluble based on the Selank core
- **Storage:** No validated stability data; lyophilized peptides of this class are typically stored at -20°C.

## Mechanism of Action

No mechanism has been measured for Adalank; the following is the documented pharmacology of Selank, which the end caps are intended to preserve. Selank modulates expression of GABAergic neurotransmission genes, inhibits enkephalin-degrading enzymes (raising endogenous leu-enkephalin half-life, a finding replicated in the 2008 clinical study), and upregulates BDNF in hippocampus after intranasal dosing. As a tuftsin analog it also carries immunomodulatory activity, shifting Th1/Th2 cytokine balance in patients with anxiety-asthenic disorders. Its anxiolysis is non-sedating and, in a 62-patient comparative study, matched the benzodiazepine medazepam on anxiety scales while adding antiasthenic effects. Whether N-acetylation and C-amidation alter any of these activities is untested.

## Key Research Findings

- Adalank is exactly what its name says: Selank with N-terminal acetyl and C-terminal amide caps, a structure calculable at C35H60N12O9 (792.9 g/mol) but absent from PubChem and PubMed.
- No experiment has tested the analog; all claims inherit from Selank, including the 62-patient GAD study showing anxiolysis comparable to medazepam.
- Selank's distinctive mechanistic finding, restoration of serum leu-enkephalin stability in anxiety patients, has never been assayed for the end-capped analog.
- Vendor claims of extended half-life are plausible class-level chemistry but remain unmeasured for this molecule.

## Adalank Pharmacokinetics: End-Cap Rationale Without Measurement

No absorption, half-life, or bioavailability measurement exists for Adalank. The case for the modifications rests on class-level peptide chemistry and on the documented pharmacokinetics of unmodified Selank.

### What Selank Pharmacokinetics Look Like

- Unmodified Selank has a plasma half-life estimated in the low minutes, yet its anxiolytic effects persist for hours after intranasal dosing because downstream gene-expression changes outlast the peptide (PMID: 18841804).
- Selank's own Pro-Gly-Pro tail already provides partial protease resistance relative to native tuftsin; the additional acetyl and amide caps in Adalank target the remaining exopeptidase attack points at the two termini.
- Russian clinical protocols use intranasal delivery for CNS effect; Adalank is sold for subcutaneous injection, a route for which neither Selank nor Adalank has published CNS exposure data.

### What End Caps Typically Change

- N-terminal acetylation removes the free alpha-amino group targeted by aminopeptidases, and C-terminal amidation removes the carboxylate targeted by carboxypeptidases; together they typically extend peptide survival in serum from minutes toward longer windows, though the magnitude for this sequence is unmeasured.
- Amidation can also change receptor interactions: many neuropeptides require a free or amidated C-terminus for activity, and the effect of capping on Selank's enkephalinase inhibition or tuftsin-receptor activity has not been assayed.
- No blood or brain concentration of Adalank has ever been reported, so vendor claims of an extended half-life remain plausible extrapolation rather than measurement.

## Safety & Tolerability

Adalank has no direct safety data in any species: no published study has administered it to an animal or a human. The adjacent evidence is the Selank clinical record, where small Russian trials reported good tolerability and no dependence phenomena, but end-cap modification creates a new molecular entity whose behavior cannot be assumed.

**Human data status:** No human data exists for Adalank. Parent Selank has small Russian clinical trials (62 patients in the largest comparative study) with favorable tolerability reporting, none of which tested the acetyl-amidate analog.

**Regulatory status:** Not approved anywhere. Selank is a registered drug in Russia; Adalank is an unregulated research chemical.

- No peer-reviewed study of Adalank (N-acetyl Selank amidate) exists; its safety, pharmacokinetics, and toxicology are entirely uncharacterized. (evidence tier: theoretical)
- In 62 patients with generalized anxiety disorder and neurasthenia, unmodified Selank showed anxiolytic efficacy comparable to medazepam with no dependence or withdrawal phenomena reported; this documents the parent peptide only. (evidence tier: human-interventional; [PMID 18454096](https://pubmed.ncbi.nlm.nih.gov/18454096/))
- A clinical study of Selank in anxiety-asthenic patients documented immunomodulatory effects (IL-6 suppression in vitro, Th1/Th2 shifts in vivo) without reported adverse safety findings over 14 days of treatment. (evidence tier: human-interventional; [PMID 18577961](https://pubmed.ncbi.nlm.nih.gov/18577961/))
- Intranasal Selank regulated hippocampal BDNF expression in rats in vivo, confirming CNS activity of the parent peptide by the clinical route; the injectable route sold for Adalank has no published CNS exposure data. (evidence tier: animal; [PMID 18841804](https://pubmed.ncbi.nlm.nih.gov/18841804/))

## Dosing Information (Research Context)

No published dosing data exists for Adalank in any species. Russian clinical protocols for parent Selank use intranasal doses of 250-500 mcg two to three times daily. Vendor discussions of injectable Adalank dosing are anecdotal extrapolations from the parent compound and cannot be referenced to primary research.

## Researched Effects

- **Anxiolytic Activity (Extrapolated From Selank)** (evidence: preliminary): The defining claim for Adalank is anxiety reduction without sedation. In the parent literature, a 62-patient Russian study found Selank's anxiolytic effect comparable to medazepam in generalized anxiety disorder and neurasthenia, with additional antiasthenic and mild psychostimulant effects and no dependence phenomena (PMID: 18454096). A 2020 fMRI study in 52 healthy volunteers showed Selank altered amygdala-temporal functional connectivity within 20 minutes of intranasal dosing (PMID: 32342318). Adalank itself has never been tested in any model.
- **Cognitive Support via BDNF** (evidence: preliminary): Intranasal Selank raised BDNF mRNA in rat hippocampus in vivo (PMID: 18841804), and a 2019 study showed Selank protected against ethanol-induced memory impairment while regulating BDNF content in hippocampus and prefrontal cortex. Vendor materials extend these findings to Adalank, but the end-capped analog has no published gene-expression or behavioral data.
- **Immunomodulation (Tuftsin-Derived)** (evidence: preliminary): Selank inherits immunotropic activity from tuftsin: in patients with anxiety-asthenic disorders it shifted Th1/Th2 cytokine balance over 14 days of treatment, and in vitro it suppressed IL-6 gene expression in peripheral blood of depressed patients at 10^-7 M (PMID: 18577961). Whether the end-capped Adalank retains tuftsin-class immune activity is unknown.
- **Stress Resilience and Enkephalin System Support** (evidence: preliminary): The 2008 clinical study found that GAD and neurasthenia patients had reduced leu-enkephalin stability in serum, which Selank treatment increased in parallel with anxiety improvement, an effect the authors report mostly in the generalized anxiety disorder patients rather than the neurasthenia group, supporting an enkephalinase-inhibition mechanism (PMID: 18454096). This is the most distinctive mechanistic claim in the Selank literature and is attributed to Adalank by inheritance only.

## Research Applications

- Anxiety Research
- Neuropharmacology
- Immunomodulation Studies
- Peptide Medicinal Chemistry

## Key Studies

### Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia

Zozulia AA, Neznamov GG, Siuniakov TS, et al. — *Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova* (2008) — [PMID 18454096](https://pubmed.ncbi.nlm.nih.gov/18454096/)

The key clinical study behind every Selank-derivative anxiolytic claim: 62 patients with generalized anxiety disorder and neurasthenia received Selank (30 patients) or the benzodiazepine medazepam (32 patients), assessed with Hamilton, Zung, and CGI scales. Anxiolytic effects were similar between drugs, while Selank added antiasthenic and psychostimulant effects. A clinical-biological substudy found patients had reduced serum leu-enkephalin stability at baseline, which rose during Selank treatment in parallel with anxiety improvement, most clearly in the generalized anxiety disorder subgroup, supporting an enkephalinase-inhibition mechanism.

### Immunomodulatory effects of selank in patients with anxiety-asthenic disorders

Uchakina ON, Uchakin PN, et al. — *Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova* (2008) — [PMID 18577961](https://pubmed.ncbi.nlm.nih.gov/18577961/)

This study examined Selank's immunotropic activity in patients. In vitro, Selank at 10^-7 M completely suppressed IL-6 gene expression in peripheral blood of depressed patients (but not healthy controls) while increasing IL-6 protein concentration in culture. In vivo, 14 days of Selank treatment shifted the Th1/Th2 cytokine balance in serum of patients with generalized anxiety disorder and neurasthenia. It documents the tuftsin-derived immune dimension of the parent peptide.

### Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivo

Inozemtseva LS, Karpenko EA, et al. — *Doklady Biological Sciences* (2008) — [PMID 18841804](https://pubmed.ncbi.nlm.nih.gov/18841804/) | [doi:10.1134/S0012496608040066](https://doi.org/10.1134/S0012496608040066)

This study established that intranasal Selank reaches the brain in functional form: it regulated BDNF mRNA expression in the rat hippocampus in vivo. It is the core experiment behind neurotrophic claims for Selank and its derivatives, and it established intranasal delivery as the reference route for the peptide family, a route that vendor injectable Adalank protocols do not follow.

### Peptide-based Anxiolytics: The Molecular Aspects of Heptapeptide Selank Biological Activity

Vyunova TV, Andreeva L, et al. — *Protein and Peptide Letters* (2018) — [PMID 30255741](https://pubmed.ncbi.nlm.nih.gov/30255741/)

This review from the Russian Academy of Sciences group that developed Selank consolidates the molecular evidence for its anxiolytic activity, including radioligand-receptor analyses and the peptide's effects on GABAergic signaling and monoamines. It frames Selank as a mild, non-sedating peptide anxiolytic in contrast to benzodiazepines, whose dependence and memory-impairment liabilities motivate the search for peptide alternatives.

### Functional Connectomic Approach to Studying Selank and Semax Effects

Panikratova YR, Lebedeva IS, et al. — *Doklady Biological Sciences* (2020) — [PMID 32342318](https://pubmed.ncbi.nlm.nih.gov/32342318/)

In 52 healthy participants, resting-state fMRI before and 5 and 20 minutes after intranasal Selank, Semax, or placebo showed that both peptides altered functional connectivity between the right amygdala and temporal cortex regions, with distinct profiles for each. It is the most direct human neuroimaging evidence that intranasal Selank engages anxiety-relevant circuitry within minutes, though it measured connectivity, not clinical anxiety.

## Frequently Asked Questions

### What is Adalank?

Adalank is the N-acetylated, C-amidated form of Selank (Ac-Thr-Lys-Pro-Arg-Pro-Gly-Pro-NH2), a vendor-market derivative of the Russian anxiolytic heptapeptide. The two end caps are meant to protect the peptide from exopeptidase degradation. It is sold only as a research chemical, and no peer-reviewed study has tested the modified compound.

### Has Adalank been studied?

No. PubMed contains no pharmacology, toxicology, or clinical literature for Adalank or N-acetyl Selank amidate, and the compound has no PubChem entry. Its calculated formula (C35H60N12O9, 792.9 g/mol) follows unambiguously from the Selank structure plus the two caps, but every biological claim derives from the parent Selank literature.

### What human evidence exists for the parent compound Selank?

A 62-patient Russian study found Selank comparable to medazepam for generalized anxiety disorder and neurasthenia, with additional antiasthenic effects (PMID: 18454096); a clinical-immunological study documented cytokine changes over 14 days of treatment (PMID: 18577961); and an fMRI study in 52 healthy volunteers showed rapid effects on amygdala connectivity (PMID: 32342318). These are small studies from one country's research system, not Western-regulator-grade trials.

### What do the acetyl and amidate modifications do?

N-terminal acetylation blocks aminopeptidases and C-terminal amidation blocks carboxypeptidases, the two enzyme classes that trim peptides from their ends. Together they generally extend serum survival and can improve membrane permeability. The trade-off is that end caps can also change receptor binding, and no assay has confirmed that Adalank preserves Selank's enkephalinase inhibition, BDNF upregulation, or anxiolytic activity.

### Is Adalank approved anywhere?

No. Parent Selank is registered as an anxiolytic drug in Russia, but that registration does not cover modified analogs. Adalank has no regulatory approval in any country and is sold as a research chemical; using it in humans would be self-experimentation with an untested compound.

## Related Peptides

- [Selank](https://peptpedia.org/peptide/selank)
- [Semax](https://peptpedia.org/peptide/semax)
- [Adamax](https://peptpedia.org/peptide/adamax)
- [N-Acetyl Semax Amidate](https://peptpedia.org/peptide/na-semax-amidate)

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This content is for educational and research purposes only. It is not medical advice, and the compounds covered are research chemicals not approved for human use unless explicitly stated otherwise.

Cite this page: Peptpedia — Research Peptide Encyclopedia, https://peptpedia.org