Selank appears in supplier catalogues and forum threads considerably more often than it appears in the indexed scientific literature. This review sets out what published research has actually investigated: what was studied, in which species, and by which route. It separates human data from animal work, and both from the dosing figures that circulate online without a traceable source. Where the evidence is thin, we say so plainly.
What Selank is
Selank is a synthetic heptapeptide. It was constructed by taking tuftsin, a naturally occurring immunomodulatory tetrapeptide with the sequence Thr-Lys-Pro-Arg, and extending it at the C-terminus with the tripeptide Pro-Gly-Pro, producing the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. The extension was intended to slow enzymatic degradation, which limits the practical half-life of tuftsin itself. The compound was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and appears in some papers under the designation TP-7.
Its research history runs closely alongside that of Semax, another Russian-developed peptide that is frequently studied in the same experiments. Our separate review of the Semax literature covers that compound in the same format.
Regulatory status: what is and is not approved
Selank is not an approved medicine in the United Kingdom or the United States. There is no MHRA marketing authorisation and no FDA approval, and we located no completed FDA- or EMA-registered clinical trials of the compound.
Secondary sources consistently report that Selank is registered in Russia as nasal drops indicated for generalised anxiety disorder and neurasthenia. We were not able to verify that registration against a primary Russian regulatory record, so it should be treated as reported rather than confirmed.
Three things are routinely conflated in peptide marketing, and they are not the same. Approval as a medicine, inclusion on a compounding list, and a favourable advisory committee vote are distinct regulatory events. In July 2026 the FDA's Pharmacy Compounding Advisory Committee reviewed seven peptides and recommended six of them for possible addition to the 503A Bulk Drug Substances List. That recommendation is non-binding, requires formal rulemaking before it changes anything, and is not drug approval. Selank was not among the seven substances reviewed at that meeting. We set out what the vote did and did not do in our explainer on the July 2026 compounding vote.
For contrast, tesamorelin is a genuine example of an approved peptide medicine: marketed as Egrifta, it holds FDA approval for the reduction of excess abdominal fat in patients with HIV-associated lipodystrophy. Selank has nothing equivalent. Material supplied by PepSource, including the tesamorelin covered in our tesamorelin evidence review, is research-grade reagent and is not the licensed medicine.
(a) Human clinical data
This is the thinnest section of the evidence base, and that is itself the most useful finding in this review.
The clearest PubMed-indexed human study is a neuroimaging investigation, Functional Connectomic Approach to Studying Selank and Semax Effects (2020). It assessed whole-brain resting-state functional connectivity in 52 healthy participants. Resting-state fMRI was carried out three times, before administration and at approximately five and twenty minutes afterwards, with participants receiving Semax, Selank or placebo. Regions of interest included the amygdala and the dorsolateral prefrontal cortex in both hemispheres.
What that study investigated is worth stating precisely, because it is frequently cited loosely. It examined acute changes in brain connectivity in healthy volunteers over a short time course. It was not an efficacy trial in a patient population, it did not measure a clinical endpoint, and it was not designed as a dose-ranging study.
A claim repeated across a large number of vendor pages holds that Russian clinical trials have enrolled more than 800 patients with generalised anxiety disorder and neurasthenia, with anxiolytic efficacy comparable to benzodiazepines such as medazepam and phenazepam. We could not verify this. Searches of PubMed did not return the trials to which that enrolment figure is attributed. Russian-language clinical literature on the compound does exist, including in journals such as Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, but we were unable to corroborate the specific enrolment total or the benzodiazepine comparison against an indexed primary record. Reporting on this point varies between sources, and until it can be checked against the underlying papers it should be treated as unverified rather than repeated as fact.
(b) Animal and preclinical work
The preclinical literature is more substantial than the human literature, though still modest in volume and concentrated among a small number of research groups.
| Study | Model | What was investigated |
|---|---|---|
| Effects of Selank on behavioural reactions and activities of plasma enkephalin-degrading enzymes (2002) | Mice with differing phenotypes of emotional and stress reactivity | Behavioural response alongside the activity of plasma enzymes that degrade enkephalins |
| Effects of heptapeptide Selank on the content of monoamines and their metabolites in the brain (2008) | BALB/c and C57Bl/6 mice | Comparative brain monoamine and metabolite content across two mouse strains |
| Efficacy of peptide anxiolytic Selank during modelling of withdrawal syndrome (2014) | Rats with stable alcoholic motivation | A single intraperitoneal injection, reported at 0.3 mg/kg, against anxiety induced by ethanol withdrawal |
| Peptide Selank enhances the effect of diazepam in reducing anxiety (2017) | Rats under unpredictable chronic mild stress | Selank in combination with diazepam under a chronic stress protocol |
Taken together, this body of work has investigated behavioural readouts in rodents, effects on enkephalin-degrading enzyme activity, and changes in brain monoamine metabolism. The mechanistic picture that emerges is of a compound acting across several pathways rather than at one well-characterised receptor. That is a description of what has been measured, not a demonstration of clinical effect.
One point on the figures above deserves emphasis. Doses in animal studies are expressed per kilogram of body weight, in a named species, by a named route, under specific experimental conditions. They are parameters of those experiments and do not convert to any other species; interspecies scaling is not a matter of arithmetic. A milligram-per-kilogram figure from a rat withdrawal model records what those investigators administered to those rats, and nothing beyond that.
(c) Protocols circulating online
A large volume of specific, confident-sounding dosing material circulates on vendor pages, forums and aggregator sites: microgram-scale intranasal regimens, milligram-scale subcutaneous regimens repeated several times weekly, and fixed cycle lengths presented as established practice.
These figures are stated with a precision that the published literature does not support. We were unable to trace them to any published trial. In most cases they carry no citation, or they cite other vendor pages that in turn cite nothing, producing a circular chain of attribution with no primary source at its origin. Figures of this kind should not be mistaken for research findings.
Route matters here too. Intranasal and subcutaneous administration are not interchangeable, yet material circulating online frequently converts between them as though the numbers carried across, which they do not.
What the literature does not establish
- No human dose-ranging study that we were able to locate in indexed sources.
- No long-term human safety data in the accessible literature.
- No substantial independent replication outside a small group of associated research institutions.
- Human pharmacokinetics that remain poorly described in accessible published sources.
- No regulatory assessment by the MHRA, FDA or EMA that would constitute an independent review of safety or efficacy.
A thin evidence base is a legitimate and useful finding. It is more informative than a confident summary assembled from unsourced figures, and researchers designing work with this compound are better served by knowing where the gaps are.
Characterisation of research material
Where published pharmacology is limited, the identity and purity of the material under study carry proportionately more weight. A heptapeptide of this kind should be characterised by HPLC for purity and by mass spectrometry for identity confirmation, with results traceable to the specific batch in hand rather than to a generic specification. Certificates of analysis for our stock are published on our lab results page.
PepSource supplies Selank as lyophilised powder and in a prepared nasal spray format, both as laboratory research reagents.
Sources
- Functional Connectomic Approach to Studying Selank and Semax Effects (PubMed 32342318)
- Effects of Selank on behavioral reactions and activities of plasma enkephalin-degrading enzymes in mice (PubMed 12432865)
- Effects of heptapeptide selank on the content of monoamines and their metabolites in the brain of BALB/C and C57Bl/6 mice (PubMed 19093364)
- Efficacy of peptide anxiolytic selank during modeling of withdrawal syndrome in rats (PubMed 24913576)
- Peptide Selank Enhances the Effect of Diazepam in Reducing Anxiety in Unpredictable Chronic Mild Stress Conditions in Rats (PMC5322660)
- FDA: July 23-24, 2026 Meeting of the Pharmacy Compounding Advisory Committee
Research use only. All products referenced are supplied strictly as research reagents for laboratory and in-vitro use, and are not for human or veterinary consumption.