Selank Nasal Spray

Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its core is tuftsin, a four-amino-acid immune peptide the body makes itself, to which the developers at the Institute of Molecular Genetics in Moscow attached the tail Pro-Gly-Pro so that the molecule does not fall apart immediately. In Russia selank is approved as nasal drops for generalised anxiety disorder and neurasthenic states, everywhere else it is a research compound without approval. The profile that draws interest: getting calmer without getting tired, without dependence and without the fog of classic tranquilisers, plus a mild nootropic and an immune-modulating component.

This entry covers the ready-to-use version: 10mg of selank dissolved in 5ml of sterile saline plus 0.4ml of bacteriostatic water, 5.4ml in total, which gives 1.85mg per ml. The pump delivers 0.1ml per spray, so about 0.185mg or 185mcg of peptide. On paper that is 54 sprays per bottle, about 50 remain usable after priming the pump. No mixing, no syringe and no conversions. The spray is only made up fresh after you order. If you prefer to mix yourself or to inject subcutaneously, selank is still available as powder in vials (5, 10 and 30mg). The selank lexicon entry has the calculator for that.

One thing matters for context: with selank the nose is not a detour but the main road. The Russian clinical studies were run with nasal drops. In animal work nasally given selank reaches the brain better than by any other route tested. Compared with drops the pump has one advantage: every spray is the same size, so you always know how much you took.

This information is for research and educational purposes only. No medical advice.

Selank has no single target receptor, it acts at several points. The longest studied pathway is the enkephalin system. Zozulya and colleagues (Bulletin of Experimental Biology and Medicine 2001) found a clearly shortened half-life of the body's own enkephalins in the blood of patients with generalised anxiety and showed in the lab that selank inhibits the enkephalin-degrading enzymes of plasma in a dose-dependent way, with an IC50 of around 15 micromolar and more potently than the reference inhibitors bacitracin and puromycin. Enkephalins are endogenous opioid peptides that damp stress and anxiety signals, so if they survive longer, the body's own brake works longer. In the same group's clinical study (2008) enkephalin half-life rose again under selank and correlated with the patients' anxiety level. The rise was clearest in generalised anxiety disorder.

The second pathway is the GABA system, the brain's main braking mechanism. Vyunova and colleagues (Protein and Peptide Letters 2018) used radioligand binding on brain membranes to show that selank enhances GABA binding in a concentration-dependent way, that is, it works as a positive allosteric modulator. Its binding site is apparently not the same as that of the benzodiazepines, though it may partly overlap. It influences what they do: combined with diazepam the effect was neither the sum of both substances nor the effect of either alone. Selank was able to block the modulatory activity of diazepam and olanzapine. Volkova and colleagues (Frontiers in Pharmacology 2016) fit this picture in rats, where 300mcg of selank per kilogram changed the expression of 45 of 84 neurotransmission genes in the frontal cortex within an hour, in a pattern that correlated with that of GABA itself.

Two side stages help explain the profile. Inozemtseva and colleagues (Doklady Biological Sciences 2008) showed that nasally given selank regulates the expression of the growth factor BDNF in the rat hippocampus, which fits the anti-asthenic and mildly nootropic component seen in the clinical studies. And through its tuftsin core selank reaches into the immune system: Kolomin and colleagues (Regulatory Peptides 2011) found that a single dose of 100mcg per kilogram in mice altered the expression of 34 of 84 inflammation genes in the spleen, notably the transcription factor Bcl6. The literature also mentions effects on serotonergic and dopaminergic signalling, where the data are thinner.

For small peptides the nose is an unusually good entrance. For selank this has been measured directly. Ashmarin and colleagues (Bioorganicheskaia Khimiia 2008) tracked tritium-labelled selank and the fragment Pro-Gly-Pro through rat tissues after intraperitoneal, nasal, intragastric and intravenous administration. The result: of all four routes, nasal dosing was the best way to deliver the peptides into the central nervous system. Part of the dose crosses the thin, richly perfused mucosa into the blood, part travels from the olfactory region along the nerve pathways towards the brain. Whatever runs down the throat ends up in the stomach. A curious detail from the same study: selank accumulates strongly in gastric tissue whichever route is used.

The route also seems to shape the pattern of effects. Vasil'eva and colleagues (Eksperimental'naia i Klinicheskaia Farmakologiia 2016) gave mice 300mcg of selank per kilogram for five days, once into the abdomen and once into the nose. Both routes were anxiolytic and nootropic, but only in the anxious BALB/c strain, not in the robust C57BL/6. Intraperitoneal dosing raised the number of GABA binding sites in the frontal cortex by 38 percent, nasal dosing instead raised NMDA binding sites in the hippocampus by 23 percent. For you this means that results from injection studies do not transfer one to one to the spray. The same goes the other way round.

On pharmacokinetics: selank does not stay intact in blood for long. Zolotarev and colleagues (Bioorganicheskaia Khimiia 2006) dissected its breakdown with tritium-labelled peptide and found the pentapeptide Thr-Lys-Pro-Arg-Pro, the tripeptide Thr-Lys-Pro and the dipeptides Arg-Pro and Gly-Pro as the main products. They also measured its distribution in brain tissue after nasal dosing. The effect, however, clearly outlasts the molecule: in the clinical study by Medvedev and colleagues (2014) the anxiolytic effect persisted for a week after the last dose. Selank apparently sets processes in motion, gene expression, BDNF, enkephalin balance, that do not need a constant blood level. One to three doses across the day are therefore enough, a steady level is not the goal.

In practice: before the first use pump two or three times into the air until a fine mist appears. Gently clear your nose first, keep your head upright, aim the nozzle slightly outward towards the nasal wall rather than at the septum, breathe in calmly while spraying and do not sniff hard. Avoid blowing your nose for 10 to 15 minutes afterwards. For two sprays prefer one per nostril or space them out, two sprays in quick succession into the same nostril tend to run down the throat.

For a peptide from the research scene selank has been studied in humans unusually often, almost exclusively in Russia. Zozulya and colleagues (Zhurnal Nevrologii i Psikhiatrii 2008) compared selank (30 patients) with the benzodiazepine medazepam (32 patients) in 62 patients with generalised anxiety disorder and neurasthenia, measured with the Hamilton, Zung and CGI scales. The anxiolytic effect was similar in both groups, while selank additionally worked against the exhaustion component and was mildly activating. In parallel, the enkephalin half-life in blood, shortened in these patients, recovered, most strongly in generalised anxiety disorder.

Medvedev and colleagues (Zhurnal Nevrologii i Psikhiatrii 2014) set selank against the benzodiazepine phenazepam in 60 patients with anxiety, phobic and somatoform disorders: pronounced anxiolysis, a mild nootropic effect and better quality of life. The after-effect stood out, the anxiolytic effect persisted for a week after the last dose. In the same group's follow-up (2015), 40 patients received selank on top of phenazepam and 30 phenazepam alone: with selank the benzodiazepine effect set in faster. Typical benzodiazepine side effects such as impaired attention and memory, sedation, longer sleep, sexual dysfunction and orthostatic problems were less frequent, also after the tranquiliser was withdrawn.

What belongs in the picture honestly: the clinical studies are small, come from the circle around the developers and are available in full only in Russian. There are no large Western double-blind trials. A US review of GABAergic substances (Doyno and White, Journal of Clinical Pharmacology 2021) rates selank as poorly studied and criticises that it is sold to US consumers as a dietary supplement without any evaluation. The mechanistic work on enkephalinases, GABA modulation, gene expression and BDNF is solid but preclinical. And what was studied were nasal drops, not a spray bottle at 1.85mg per ml. The spray counts given here are a conversion, not a study dose.

• Nose: mild burning, dryness, sneezing or a brief tingle after spraying are the most common observation, the solution itself hardly irritates, it is usually the jet. Pause if irritation persists or the nose bleeds.
• Central effects: selank is considered non-sedating. In the comparative studies it came out markedly better than the benzodiazepines on sedation and cognitive side effects. Some users still report brief tiredness, others inner restlessness or mild activation, more rarely headache. Both are usually mild and fade after stopping.
• Dependence: the clinical studies describe neither tolerance nor withdrawal, the effect even persisted after stopping. That sets selank apart from benzodiazepines, but it rests on small studies over a few weeks, not on long-term data.
• Interactions: selank modulates the GABA-A receptor and, according to Vyunova and colleagues (2018), changes the effect of diazepam on GABA binding in a non-additive way. Caution with benzodiazepines, Z-drugs, alcohol or other GABAergic substances is warranted, not because a dangerous potentiation has been shown, but because the direction of the interaction is hard to predict.
• Immune system: through its tuftsin core selank alters the expression of inflammation-related genes. Anyone with an autoimmune condition or on immunosuppression should put that question to a doctor.
• Data gaps: no data for pregnancy, breastfeeding, children or adolescents. No long-term data on continuous use either. Hence phases rather than continuous running.

The spray belongs in the fridge at 2 to 8 degrees, upright, capped and protected from light, for example in its outer packaging. Do not freeze it, cycling between frozen and thawed can harm both the peptide and the pump. A few hours or days at room temperature in the post or in a bag do no harm, but the bottle should not sit warm for long.

Selank is a small, robust peptide and stays stable in cold solution for months. The limiting factor with the spray is not chemistry but hygiene: only 0.4ml of the 5.4ml is bacteriostatic water, so its preservative is heavily diluted and protects the solution only to a limited degree. So wipe the nozzle with a clean tissue after each use, put the cap back on, do not share the bottle and only rest the tip just inside the nostril instead of pushing it in deep. If the solution turns gel-like, lumpy or smells different, stop using it. Slight cloudiness on its own is not a reason.

In practice there is no storage problem: at 1 to 4 sprays a day the bottle is empty after 2 to 7 weeks, within the phase it is meant for. If you pause for longer, leave the spray in the fridge and pump once into the air before the next use until a fine mist appears again.