What is selank?

Selank is a synthetic heptapeptide analogue of tuftsin, the Thr-Lys-Pro-Arg fragment of the human immunoglobulin G heavy chain, extended at the C-terminus with three natural amino acids, Pro-Gly-Pro. It was designed at the Institute of Molecular Genetics of the Russian Academy of Sciences with the V.V. Zakusov Research Institute of Pharmacology. ^[1]

The Pro-Gly-Pro tail has a stated purpose. The Institute of Molecular Genetics group writes that it was added to improve metabolic stability and lengthen the peptide's action. ^[1] Moscow groups reported in 2005 that Pro-Gly-Pro-containing peptides show stability comparable with major pharmacological preparations. ^[12]

Selank carries older names. A 1995 rat study called it TP-7, and PubChem lists TP-7 and Selanc as synonyms. ^[2][3] Almost all of its literature comes from a small circle of Moscow institutes. That shapes every other section: the evidence is real, it is narrow, and much of it is published in Russian.

Selank in 10mg vials is in stock with a batch certificate.

Selank's mechanism has been described two ways, both from Russian laboratory work. The first is inhibition of the enzymes that break down enkephalins, the body's own opioid peptides. The second is modulation of GABA receptor binding.

The enzyme work came first. In 2001, Kost and colleagues reported that selank inhibited enkephalin-degrading enzymes from human serum with an IC50 of 20 µM, and that semax did the same at 10 µM. ^[5] A second 2001 paper reported an IC50 of 15 µM for plasma enkephalin hydrolysis and proposed this as the basis of selank's anxiety-related effects. ^[4] In mice, a 2002 study linked the behavioural result to a longer half-life of plasma leu-enkephalin, and only in the BALB/c strain. ^[13]

The GABA work came later. A 2018 radioligand study from the Institute of Molecular Genetics reported that selank acted on [3H]GABA binding as a positive allosteric modulator, and that it changed the binding effects of diazepam and olanzapine. ^[6] Gene-expression studies followed the same lead:

• Rat brain (2016). In the frontal cortex of 30 male Wistar rats, 45 of 84 neurotransmission genes changed expression 1 hour after selank or GABA, and 22 changed at 3 hours. ^[1]
• Human neuroblastoma cells (2017). In IMR-32 cells, selank alone produced no change in the mRNA levels of the genes studied. Combined with GABA, it almost completely suppressed the changes GABA caused. ^[14]

The two results pull in different directions. Rat brain tissue showed wide gene changes, while a human cell line showed none from selank alone. The authors of the cell study concluded that selank has no direct effect on those GABAergic genes in IMR-32 cells. ^[14]

A third line of work concerns the immune system, inherited from tuftsin. In mouse spleen, 34 of 84 inflammation-related genes changed expression after selank. ^[15] A 2009 study reported antiviral activity against an influenza A strain in cell culture and in animals. ^[16]

Selank is a linear peptide of seven L-amino acids with a free N-terminal amine and a free C-terminal carboxylic acid. It carries no fatty acid chain, no amidation and no unnatural residues, which makes it one of the simplest molecules in the research peptide range.

The identifiers come from PubChem, which we queried on 29 September 2026. ^[3] The tuftsin origin comes from the Institute of Molecular Genetics papers. ^[1]

Three structural facts matter at the bench.

1. Selank is basic and very water-loving. Lysine, arginine and the N-terminal amine carry positive charges at neutral pH, against one C-terminal carboxylate, a net charge of about +2. PubChem's computed XLogP of -6.1 marks it as strongly hydrophilic. ^[3]
2. Research material is often an acetate salt. Two Institute of Molecular Genetics studies describe their material as the Thr-Lys-Pro-Arg-Pro-Gly-Pro diacetate salt. ^[1][17] Two acetates add about 120 g/mol, so a pure diacetate would be about 86% peptide by weight before any water. Net peptide content on a certificate captures this.
3. The sequence avoids the residues most prone to oxidation. Selank contains no cysteine, methionine or tryptophan, the residues Sigma-Aldrich flags as prone to air oxidation. ^[18]

Research on selank has examined anxiety-like behaviour, learning, gene expression and immune markers in rodents and cells, plus a few small clinical studies in Russian patients with anxiety disorders. The table lists the studies we read, by year and model. Each finding describes the study population, and none describes a research vial.

Three patterns stand out. The work is concentrated in a few Moscow institutions, often with overlapping authors. The clinical studies compare selank with benzodiazepines and appear in Russian journals. And the one placebo arm we found sat in a brain-imaging study of healthy volunteers, which measured connectivity and no clinical outcome. ^[22]

The selank evidence base is thin on independence and thin on controls. Four limits are worth stating plainly.

1. No placebo-controlled trial in patients. The three anxiety studies we found compared selank with medazepam or phenazepam, with 60 to 70 patients each. ^[20][7][8]
2. No independent replication outside Russia. A 2021 US review in the Journal of Clinical Pharmacology calls selank a poorly studied Russian drug. ^[23] A Belgian medicines laboratory wrote in 2020 that, to its knowledge, selank and semax had not completed any clinical trials. ^[24]
3. Abstracts only for most human data. The clinical papers are in Russian, and their English abstracts carry no adverse-event rates for selank itself.
4. The studies used their institutes' own material. Identity and purity of a research vial are separate questions, and a batch certificate answers them.

None of the selank abstracts we read reports a specific adverse event rate for selank. The published record on harm is sparse, and it comes mostly from animal work and one regulator statement.

• Human study, 70 patients (2015). Adding selank to phenazepam was reported to reduce phenazepam's undesirable effects, including attention and memory impairment, asthenia and sedation, rated on the UKU scale. ^[8] This describes phenazepam's side effects, with no separate rate given for selank.
• Animal study, cats (2005). Under anaesthesia, selank given intravenously produced a 32% fall in arterial pressure for the first 1 to 3 minutes and a 24% rise in cerebral blood flow. Heart rate and breathing rate were unchanged. ^[25]
• Cell study, mouse embryonic stem cells (2017). Selank at 100 µM reduced the share of stem cells becoming GABA-positive neurons by 61% against control. The authors concluded the peptides tested had no toxic effect during embryonic development. ^[26]
• US regulator (FDA). The FDA lists selank acetate (TP-7) among bulk substances previously in category 2 whose compounding nominations were withdrawn. It states that compounded selank acetate may pose a risk of immunogenicity for certain routes because of aggregation and peptide-related impurities, and that FDA lacks important information on safety in humans. ^[9]

These are the published observations and one regulator's assessment. They give no basis for a tolerability conclusion in either direction.

Selank is not named in the Poisons Standard. We searched the full text of the June 2026 instrument (F2026L00633), which commenced on 1 June 2026, and found no entry for selank. Its Schedule 4 list runs from selegiline and selenium to semaglutide with nothing between for selank. ^[10]

Not named is a narrow statement. It means selank has no schedule of its own, and it says nothing about how state law, import rules or therapeutic goods law apply to a given use. Our guide to Australian peptide law and the Poisons Standard explains each schedule and the rules around them.

For sport, selank is not named on the WADA 2026 Prohibited List, effective 1 January 2026. Class S0 prohibits at all times any pharmacological substance with no current approval by any governmental regulatory health authority for human therapeutic use. ^[11] Selank is described in Russian literature as a peptide pharmaceutical product, but we did not verify its approval status with any regulator, so we cannot say whether S0 applies. ^[26] Sport Integrity Australia states that possession or use of prohibited peptide products by athletes can lead to an anti-doping rule violation. ^[27]

In the United States, the FDA's Drugs@FDA database returned no match for selank when we searched on 29 September 2026. ^[28]

Selank and semax are sibling molecules from the same Moscow institute. Both are heptapeptides that end in Pro-Gly-Pro, built on different natural fragments.

The enzyme figures come from the same 2001 paper. ^[5] The FDA's July 2026 compounding committee agenda listed semax, and selank did not appear on it. ^[29] Semax's formula data come from the same PubChem checks we ran for every compound. Semax also contains methionine, a residue prone to air oxidation, which selank lacks. Selank vs semax sets out the full comparison, and both sit in our cognitive and sleep research peptides range.

No published stability study covers research-grade selank, so storage follows general peptide guidance. Bachem advises keeping peptides as lyophilised powder in a tightly closed container below -15°C for long storage. It adds that peptides should not be stored in solution, and that frozen solutions keep for a few weeks. ^[30]

For solvents, the published studies give two examples. Volkova and colleagues dissolved selank diacetate in deionised water at 10 mg per mL. ^[1] Kasian and colleagues dissolved it in saline at 12 mg per mL. ^[17] Selank's basic charge and very low XLogP fit that. Bachem's solubility guidance states that basic peptides dissolve in a small amount of dilute acid if needed, and names PBS at pH 7.0 to 7.4 as the safest diluent. ^[31]

We stock BAC Water, sterile water with 0.9% benzyl alcohol, in 3ml vials for A$8. Record the solvent, volume, resulting mg per mL and date on the vial label. Our guides on how to reconstitute peptides and peptide storage cover the method, temperatures, light and repeated freezing and thawing.

Peptides Collective sells selank for laboratory research use only, in 10mg vials of lyophilised powder from A$58. Stock ships from Western Australia with tracking.

Every batch is tested by an independent lab before it goes on sale. The certificate reports purity by HPLC and identity by mass spectrometry, and it is published under the batch number printed on the vial. You can search the certificate of analysis library by that number and match the report to the vial in your hand.

Read the certificate against the structure table. For selank, the protonated ion [M+H]+ should sit near m/z 752.44 and the doubly charged ion near m/z 376.72, both calculated from PubChem's monoisotopic mass of 751.434 Da. ^[3] Net peptide content will sit below 100% if the material is an acetate salt. Our guide on how to read a peptide certificate of analysis explains the HPLC trace, the mass spectrum and net peptide content. The selank product page links the certificate for the current batch.

Selank is a 751.9 g/mol, seven-residue analogue of tuftsin, designed in Moscow with a Pro-Gly-Pro tail for stability. Its literature proposes enkephalinase inhibition and GABA receptor modulation, drawn mostly from rodent and cell work, plus a few small Russian studies without placebo control in patients. It has no entry in the June 2026 Poisons Standard and no mention on WADA's 2026 List. For a research vial, the batch certificate settles what is inside.