What is Selank? A plain-English guide

01The short version

Selank is a short synthetic peptide from the same Russian institute that produced Semax. Where Semax was built for attention and learning, Selank was built for the other half of the day: it is studied for its effect on stress, and for clear thinking under pressure, without the sedation that comes with most things that calm you down. It is taken as a nasal spray and it is the only active ingredient in CALM-02.

02What Selank is

The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro. The first four amino acids are tuftsin, a natural fragment of an immune protein that the body produces itself. As with Semax, the Institute of Molecular Genetics attached the Pro-Gly-Pro tail to stop the fragment being broken down in minutes, which is what makes it usable as a spray. Selank was registered for clinical use in Russia in 2009 and has been in use there since.

It is not a benzodiazepine, not an antihistamine and not a sedative. It does not act on the receptors those drugs act on, which is why it does not cause drowsiness or dependence in the studies that looked.

03What the research measured

The Russian clinical literature on Selank is mostly in patients with anxiety disorders, and it consistently reports a reduction in anxiety scores comparable to a low-dose benzodiazepine, without the sedation or the withdrawal. Mechanistically, animal work points to an effect on GABA signalling (the brain's main calming system) and on the balance of serotonin and enkephalins, the body's own opioid-like peptides.

The important caveats: the trials are Russian, mostly small, and in patients rather than healthy people. There is no equivalent of Semax's shift-work study for Selank. What healthy users describe, a steadier baseline and a shorter recovery after a stressful hour, is consistent with the data but has not been measured in a trial.

04Selank vs Semax

Same lab, same delivery route, different job. Semax pushes attention and learning; Selank settles the system so attention has somewhere to land. People who are wired and scattered often do better on Selank first; people who are calm but foggy want Semax. Many use both: Semax in the morning, Selank late afternoon or before an evening that needs to be calm. The full comparison is in Semax vs Selank.

05How Selank is used

The clinical doses are in the same range as Semax, around 0.25 to 1 mg intranasally, once or twice a day. Effects are usually noticed within 15 to 30 minutes and last several hours. Unlike a stimulant it can be taken in the afternoon or evening without disturbing sleep; many users prefer it then. Dosing, side effects and what to expect are covered in the Selank dosage guide.

06Selank in the UK

Selank is not a licensed medicine in the UK and is not a controlled substance. The position is the same as for Semax and explained in Is Semax legal in the UK?. CALM-02 is made in the UK at 99.9% purity and is currently on a waiting list ahead of its first release.