Selank

What it is

Selank's starting point, tuftsin, is a short peptide the immune system makes on its own, and Selank is built by attaching an extra short chain of amino acids onto that natural sequence. Researchers describe it as retaining some of tuftsin's immune-related activity while gaining separate effects on brain chemistry.

Reported research on its mechanism describes Selank as acting on several brain-signaling pathways simultaneously, including the receptor for GABA, a brain chemical that has a calming effect, along with the systems that use serotonin and dopamine. Researchers have proposed this combination as a route to anxiety-related effects without some of the drawbacks associated with a different, older class of anti-anxiety medicines.

How it is studied

Selank's research record spans rat studies looking at gene activity and BDNF, a nerve-growth protein, alongside human studies in people diagnosed with generalized anxiety disorder or a related condition called neurasthenia, tracked over several weeks of treatment.

What studies report

• In rats, giving Selank changed the activity of 45 out of 84 tested genes involved in communication between nerve cells within an hour, a pattern researchers describe as pointing to a calming, GABA-related mechanism, GABA being a brain chemical with a calming effect, similar to how benzodiazepine anti-anxiety medicines work. [1]
• A separate rat study reported that Selank given into the nose changed the activity of the gene for BDNF, a nerve-growth protein, in the hippocampus, a brain region tied to memory. [2]
• In a later rat study, Selank prevented the rise in BDNF levels in the hippocampus and frontal cortex that long-term alcohol exposure normally causes, and it also protected memory and attention in rats going through alcohol withdrawal. [3]
• In a trial comparing it directly against another medicine, in people with generalized anxiety disorder or a related condition called neurasthenia, Selank reduced anxiety about as well as medazepam, an approved benzodiazepine anti-anxiety medicine, and was also linked to reduced fatigue-like symptoms and a mild stimulant-like effect that medazepam did not show. [4]

What is not known

Much of Selank's research, including its main human trial, comes from research groups within the same country and research tradition that developed it, so independent replication outside that setting is limited in the sources reviewed. A specific claim in some secondary summaries, that Selank's calming effect in people lasts for about a week after treatment stops without any sign of dependence, could not be traced to a primary paper with that detail and is not repeated here. How its reported immune-related activity, inherited from tuftsin, interacts with its brain effects in people has not been separately studied.

Reported adverse findings

• The human trial reviewed here compared Selank against an approved anti-anxiety medicine rather than a placebo and reported anxiety-reducing effects of similar size for both, without describing a formal side-effect comparison between the two. [4]

Regulatory status

The FDA has not approved Selank. Russia, where it was developed, lists it as a registered pharmaceutical there, a status that carries no weight in other countries.