Selank safety research: the findings, including the awkward ones

Published August 28, 2026 · Artemis Labs

Selank’s safety literature is thin, preclinical, and contains two findings that rarely appear in summaries of the compound. A 2017 blood-clotting study using thromboelastography found that three related peptides all pushed coagulation toward hypocoagulation — clotting less readily — and that “Selank demonstrated the maximal anticoagulation potency” of the three. A mouse embryonic stem cell study concluded that these peptides “do not produce toxic effect during the embryonic and fetal period of life,” while reporting in the same abstract that Selank reduced the proportion of one neuron type by 61% against control. Neither finding has been followed up in humans. Both belong on the page.

Key findings

• Thromboelastography, three glyproline peptides: “The parameters R, K, MA, S, TMA, and J changed to hypocoagulation direction in comparison to the control. At this, Selank demonstrated the maximal anticoagulation potency” (PMID 29181670).
• Mouse embryonic stem cells: “Analysis of differentiation of embryonic stem cells into GABA+ neurons showed that Selank, thyroliberin (100 μM), and NGF (100 ng/ml) decrease the ratio of these cells by 61, 58, and 87%, respectively, in comparison with the control” (PMID 29063333).
• The same study’s overall conclusion: “these peptide compounds do not produce toxic effect during the embryonic and fetal period of life.”
• An outside US review classes Selank among “poorly studied Russian drugs with GABAergic mechanisms that are inexplicably sold to US consumers as dietary supplements” (PMID 34396551).

The anticoagulant signal

Thromboelastography measures how blood clots over time — how long clotting takes to start, how fast it builds, how strong the clot gets. It produces several parameters at once rather than a single number, which is why the 2017 study lists six of them.

The researchers tested three peptides from the glyproline family, all sharing the Pro-Gly-Pro motif: His-Phe-Arg-Trp-Pro-Gly-Pro, Selank itself, and Pro-Gly-Pro alone. Every parameter moved toward hypocoagulation, and Selank moved them most.

Two things make this worth publishing. It is a measured effect on a system nobody looks at when studying an anxiety compound, so it would be easy to miss entirely. And it fits a pattern visible elsewhere in this literature: the Pro-Gly-Pro tail is not inert packaging. It has its own biology, it appears in several Russian research peptides, and effects attributed to a whole molecule sometimes trace to it — the same conclusion the immune gene studies reached from a different direction, described on our immune research page.

What the study does not establish is any consequence. It is a laboratory measurement on blood, not a bleeding outcome in an animal or a person, and no follow-up appears in the record.

The stem cell study, read in full

The 2017 mouse embryonic stem cell study tested several peptide preparations, including Selank and Semax, on cell proliferation, survival and differentiation into neurons.

Its headline conclusion is reassuring, and it is the sentence that gets quoted: these compounds “do not produce toxic effect during the embryonic and fetal period of life.”

The abstract also contains a specific number that is almost never quoted alongside it. When the researchers looked at differentiation into GABA-producing neurons, Selank reduced the proportion of those cells by 61% relative to control. Thyroliberin reduced it by 58% and nerve growth factor by 87%.

Both statements are the authors’. They are not in conflict: a change in which cell types a stem cell becomes is not the same as killing cells, and the study’s toxicity endpoints were proliferation and survival. But a 61% shift in the population of a specific neuron type is a substantive observation, and quoting only the reassuring half of an abstract is exactly the practice that makes vendor summaries untrustworthy.

It is also notable that the affected cell type is GABAergic — the same system Selank’s proposed mechanism runs through, covered on our GABA research page.

What has not been measured at all

The gaps here are larger than the findings.

No long-term toxicology study of Selank appears in the retrieved record. No carcinogenicity study, though one 2013 paper looked at oligopeptides and spontaneous carcinogenesis in mice. No reproductive toxicology beyond the stem cell work above. No study of dependence or withdrawal from Selank itself, despite an entire research lane about its effect on withdrawal from other substances.

The human trials reported tolerability, and the 2015 add-on study reported fewer benzodiazepine-related side effects in the combination arm. Those are tolerability observations in trials of 60 to 70 patients, run by the group developing the compound, without placebo controls — useful, and not a substitute for a safety program.

What the research does not show

Nothing in this literature establishes that Selank is safe in humans, and nothing establishes that it is harmful. The honest description is that the question has barely been asked.

The anticoagulant finding is an in vitro measurement with no reported clinical follow-up.

The stem cell study’s reassuring conclusion applies to the endpoints it measured — proliferation and survival — and sits alongside a substantial reported change in one differentiation outcome.

And the compound is in circulation outside research settings: a Belgian forensic laboratory identified Selank in seized pharmaceutical preparations, and reported that an online search found peptides of this kind offered for sale openly. That is a statement about a market, and it is part of why the absence of safety data matters.

Frequently asked questions

Does Selank affect blood clotting?

In a laboratory thromboelastography study, it pushed clotting parameters toward hypocoagulation more strongly than two related peptides. No animal or human bleeding outcome has been reported.

Is Selank toxic?

The one toxicity-focused study, in mouse embryonic stem cells, concluded these peptides do not produce a toxic effect on the endpoints it measured, while reporting a 61% reduction in one neuron type’s share of differentiated cells.

What safety data came out of the human trials?

Tolerability observations only, in studies of 60 to 70 patients without placebo arms. See our human trials page for what those studies were and were not designed to answer.

Is Selank prohibited in sport?

We do not publish a status either way. We could not verify one against the primary document, and a negative claim about a live regulatory list is exactly the sort of thing that should not be asserted from a secondary source.

References

1. Rogozinskaya EY, Lyapina MG. Bull Exp Biol Med. 2017. PMID 29181670. DOI 10.1007/s10517-017-3950-4.
2. Kobylyanskii AG, Zolotarev YA, Andreeva LA, Grivennikov IA, Myasoedov NF. Bull Exp Biol Med. 2017. PMID 29063333. DOI 10.1007/s10517-017-3891-y.
3. Doyno CR, White CM. J Clin Pharmacol. 2021. PMID 34396551. DOI 10.1002/jcph.1922.
4. Vanhee C, Francotte A, Janvier S, Deconinck E. Drug Test Anal. 2020. PMID 31667971.
5. Medvedev VE, Tereshchenko ON, Kost NV, Ter-Israelyan AY, Gushanskaya EV, Chobanu IK, et al. Zh Nevrol Psikhiatr Im S S Korsakova. 2015. PMID 26356395.

Methodology: quotations are verbatim from the published abstracts of the cited studies, retrieved through NCBI E-utilities on August 28, 2026. Where an abstract contains both a reassuring conclusion and a specific contrary measurement, both are reported.

All compounds sold by Artemis Labs are for laboratory research use only. Nothing on this page is medical advice, and no statement has been evaluated by the FDA.