Selank (nasal spray)

Selank (TP-7) is a synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro: the endogenous immunopeptide tuftsin, an immunoglobulin G fragment, extended with a Pro-Gly-Pro tail that confers peptidase resistance and allows central access. It was developed at the Institute of Molecular Genetics in Russia, where it has been an approved prescription anxiolytic since 2009 for generalised anxiety disorder and neurasthenia, marketed as the nasal spray Selanc and listed on the Russian List of Vital and Essential Drugs. It is not FDA approved and circulates in the United States as a research chemical.

Intranasal delivery bypasses the gastrointestinal tract and first-pass hepatic metabolism and gives access to nose-to-brain transport along olfactory and trigeminal pathways. Stated intranasal bioavailability is 92.8 per cent, and this is the route used in every published clinical trial. Dosing is expressed per actuation rather than per drawn volume: the atomizer dispenses 100 mcg per spray, so titration proceeds in 100 mcg increments with no reconstitution arithmetic.

The differentiator against conventional anxiolytics is the absence of sedative and dependence liability. In Zozulya et al. (2008), 62 patients with GAD and neurasthenia were randomised between Selank (30 patients) and medazepam (32 patients); anxiolysis was comparable, but the Selank arm additionally showed antiasthenic and psychostimulant effects while avoiding the benzodiazepine's sedation and cognitive impairment. SSRIs, by comparison, require 4 to 6 weeks to take effect and carry emotional blunting.

Selank acts through convergent modulation rather than single-target agonism.

GABAergic modulation. Selank is an allosteric modulator of the GABAergic system rather than a direct GABA-A ligand. Volkova et al. (2016) profiled 84 neurotransmission-related genes in rat frontal cortex, finding 45 differentially expressed at 1 hour and 22 at 3 hours, with strong positive correlation to the signature produced by direct GABA administration. The absence of orthosteric GABA-A binding is the mechanistic basis for the lack of sedation, amnestic effect, tolerance and withdrawal seen with benzodiazepines, which force channel opening directly.

Enkephalinase inhibition. Zozulya et al. (2001) demonstrated dose-dependent inhibition of plasma enkephalin hydrolysis with an IC50 of 15 micromolar, exceeding the potency of bacitracin and puromycin. Patients with GAD show shortened enkephalin half-life relative to healthy controls, and Zozulya et al. (2008) found decreased enkephalin levels correlating with symptom severity that rose under Selank treatment — an endogenous opioid-peptide-sparing mechanism rather than exogenous opioid activity.

Monoaminergic modulation. Serotonergic and dopaminergic tone is shifted across systems rather than by single-transporter reuptake blockade. The 3-hour timepoint in Volkova et al. (2016) showed unique activation of Drd5, a dopamine D5 receptor gene supporting long-term potentiation and consequently learning and memory consolidation — the likely substrate of the reported procognitive component.

Neurotrophic signalling. BDNF expression rises in hippocampus and prefrontal cortex. Inozemtseva et al. (2008) confirmed BDNF regulation in rat hippocampus specifically after intranasal administration; Kolik et al. (2019) attributed protection against ethanol-induced memory impairment to BDNF regulation in hippocampus and frontal cortex.

Immunomodulation. Tuftsin heritage is retained: activation of tissue-resident macrophages in liver, spleen and lymph nodes, leukocyte mobilisation, and interferon secretion. Yasenyavskaya et al. (2021) reported reduced IL-1 beta, IL-6 and TNF-alpha with restored IL-4 and suppressed TGF-beta 1 under social stress; Kolomin et al. (2011) found 34 inflammation-related genes altered in mouse spleen, notably Bcl6; Uchakina et al. (2008) showed Th1/Th2 rebalancing and complete suppression of peripheral blood IL-6 gene expression after 14 days in anxiety-asthenic patients.

Route dependence. Vasil'eva et al. (2016) compared intranasal and intraperitoneal administration in BALB/c and C57BL/6 mice: intraperitoneal Selank raised frontal cortex GABA receptor binding by 38 per cent with no NMDA change, while intranasal Selank raised NMDA receptor binding by 23 per cent with no GABA change. Anxiolytic and nootropic effects appeared only in the anxiety-prone BALB/c strain. The two routes therefore carry somewhat different neurochemical profiles, attributable to pharmacokinetics and route-specific metabolism.

Primary effect is non-sedating anxiolysis with a benzodiazepine-comparable magnitude and no dependence liability. Zozulya et al. (2008) found equivalent anxiolysis to medazepam in 62 patients, with additional antiasthenic and psychostimulant effects absent from the comparator. Medvedev et al. (2014) reported pronounced anxiolysis plus mild nootropic effect against phenazepam, with therapeutic benefit persisting approximately one week after the final dose and improved quality of life. Medvedev et al. (2015) showed that adding Selank to phenazepam reduced benzodiazepine-associated attention and memory impairment, sedation, sleep prolongation, sexual disturbance and emotional indifference, both during treatment and after benzodiazepine withdrawal. Kasian et al. (2017) found Selank alone most effective against elevated anxiety in unstressed rats, and Selank plus diazepam most effective under unpredictable chronic mild stress.

Cognitive: BDNF elevation, Drd5 activation and enkephalin preservation underpin reported gains in focus, memory consolidation, mental clarity and processing speed; Kolik et al. (2019) documented prevention of ethanol-induced memory and attention disturbance during alcohol withdrawal at 0.3 mg/kg daily for 7 days.

Mood: simultaneous serotonergic, GABAergic and enkephalinergic modulation produces stabilisation without the emotional blunting characteristic of SSRI therapy.

Stress and immune axis: cytokine normalisation plus neurotrophic support restores stress reactivity rather than masking symptoms. Retained tuftsin activity includes macrophage activation in liver, spleen and lymph nodes, leukocyte mobilisation against infectious and neoplastic targets, and interferon stimulation; in influenza comparison it substantially outperformed recombinant interferon-alpha.

Central circuitry: Panikratova et al. (2020) used resting-state fMRI in 52 healthy participants and found both Selank and Semax altered functional connectivity between right amygdala and right temporal cortex, a circuit implicated in emotion regulation and cognitive processing.

No tolerance, dependency or withdrawal has been documented, and discontinuation requires no taper. The route alters kinetics, not pharmacology beyond the NMDA-versus-GABA binding divergence noted above: 92.8 per cent bioavailability, onset within 15 to 30 minutes, supporting 2 to 3 administrations per day rather than a single daily injection.

Neznamov et al. (2012) dosed 20 GAD patients aged 24 to 52 at 2700 mcg per day intranasally. Forty per cent were rapid responders with abrupt full-symptom reduction within 1 to 3 days, HARS falling from 20.3 to 7.0 by Day 3; the remaining 60 per cent responded gradually, reaching clinically significant change at Day 14. Rapid responders were characterised by more prominent asthenic and cognitive symptoms at baseline and marked EEG reactivity after a single dose — increased beta rhythm with decreased theta and low-frequency alpha. Baseline asthenic-cognitive loading is therefore a plausible predictor of rapid response.

Pharmacokinetics are dissociated from pharmacodynamics. After intranasal administration Selank is detectable in blood within 30 seconds, peaks rapidly, and plasma concentration declines within 5 to 5.5 minutes, with no metabolites in urine, indicating rapid tissue peptidase degradation. Downstream effects on gene expression, BDNF and neurotransmitter balance persist far beyond plasma presence.

Reported trajectories from user communities, which are anecdotal rather than published: calming and clarity within the first few days of consistent use, stronger nootropic and mood-stabilising effects at 1 to 2 weeks, and the most pronounced memory and learning effects at 4 to 6 weeks. Subjective onset of 10 to 20 minutes after an intranasal dose is common, with single-dose duration commonly reported at 12 to 24 hours; others report a week or more before a meaningful shift. Inter-individual variation is substantial.

Evaluation window is 1 to 2 weeks of consistent use. Discontinuation requires no taper and produces no withdrawal, with anxiolysis persisting approximately one week after the final dose on published data.

Ceiling effects: not a hypnotic, and the evidence base is strongest for generalised anxiety disorder rather than panic disorder or severe social anxiety, where user reports are inconsistent. Product quality variance across nasal spray sources is a recurring confound in reports of non-response.

No reconstitution. Per-actuation dose is 100 mcg, so the practical range of 200 to 400 mcg per administration corresponds to 2 to 4 sprays and titration proceeds in 100 mcg steps. No vial fill volume or total mass is stated for the atomizer.

Practical intranasal protocol: 200 to 400 mcg per administration, 2 to 3 times daily, total daily 400 to 1000 mcg. Listed doses are per administration, not daily totals divided across administrations.

Split every dose between both nostrils. This increases exposed mucosal surface area, reduces runoff into the pharynx and loss to swallowing, and compensates for the nasal cycle, where congestion and mucus render one nostril less absorptive than the other at any given time.

Timing: morning and early afternoon preferred. Selank is not classically stimulating, but its effects on alertness and cognition mean some users report difficulty winding down with late dosing. Fasted state unnecessary — the intranasal route bypasses the gastrointestinal tract and there is no interaction with food absorption. Storage: refrigerate the atomizer.

Cycling: 10 to 14 days for acute stress or a discrete event, per the Russian clinical protocol; 4 to 6 weeks for generalised anxiety or cognitive support, per extended practice-derived use; 1 to 3 week break between cycles. No taper is required on discontinuation, and no tolerance development has been documented, so cycling is precautionary rather than evidence-driven.

Reference points from the literature: the approved Russian 0.15 per cent nasal spray is dosed at 2 to 3 drops per nostril, 3 times daily for 10 to 14 days; Neznamov et al. (2012) used 2700 mcg per day intranasally as 900 mcg three times daily; Zozulya et al. (2008) did not specify the Selank dose in the available abstract. Animal work used intraperitoneal doses of 300 mcg/kg per day for 5 days in the route-comparison study and 0.3 mg/kg daily for 7 days in the memory-protection study. The commonly used subcutaneous pattern is 100 to 300 mcg once daily in the morning for 4 to 6 weeks, and no published dose-finding study supports it. The practical protocols above derive from clinical practice patterns and usual practice, not dose-finding trials.

Selank has a stronger human dataset than most research peptides, almost entirely Russian in origin, and has been an approved prescription medication in Russia since 2009 for generalised anxiety disorder and neurasthenia, listed among vital and essential drugs.

Zozulya et al., 2008: 62 patients with GAD and neurasthenia, 30 on Selank and 32 on medazepam. Equivalent anxiolysis, with additional antiasthenic and psychostimulant effects unique to the Selank arm. The same work identified decreased enkephalin levels correlating with symptom severity, rising with treatment. Medvedev et al., 2014 compared Selank with phenazepam and reported pronounced anxiolysis plus mild nootropic effect, with benefit persisting approximately one week after the final dose and improved quality of life. Medvedev et al., 2015 showed that Selank added to phenazepam attenuated benzodiazepine adverse effects — attention and memory impairment, sedation, increased sleep duration, sexual disturbance, emotional indifference — both during treatment and after withdrawal.

Neznamov et al., 2012: 20 patients aged 24 to 52 on 2700 mcg per day intranasally (900 mcg three times daily). Forty percent were rapid responders with HARS falling from 20.3 to 7.0 by day 3; 60 percent reached clinically significant change at day 14. Rapid responders had more prominent asthenic and cognitive symptoms at baseline and clear EEG shifts after a single dose — increased beta, reduced theta and low-frequency alpha.

Mechanistic work: Volkova et al., 2016 profiled 84 neurotransmission genes in rat frontal cortex, with 45 altered at 1 hour and 22 at 3 hours, strongly correlated with direct GABA administration, supporting allosteric GABAergic modulation rather than GABA-A orthosteric binding, plus unique Drd5 activation at 3 hours. Zozulya et al., 2001 reported dose-dependent inhibition of plasma enkephalin hydrolysis with an IC50 of 15 micromolar, more potent than bacitracin and puromycin. Inozemtseva et al., 2008 showed intranasal Selank regulates hippocampal BDNF; Kolik et al., 2019 showed 0.3 mg/kg daily for 7 days prevented ethanol-induced memory and attention disturbance via BDNF in hippocampus and frontal cortex. Kasian et al., 2017 found Selank plus diazepam most effective under unpredictable chronic mild stress, with Selank alone most effective in the absence of chronic stress. Immunology: Yasenyavskaya et al., 2021 (reduced IL-1 beta, IL-6, TNF-alpha, restored IL-4, suppressed TGF-beta 1), Uchakina et al., 2008 (14 days of treatment altered Th1/Th2 balance and completely suppressed peripheral blood IL-6 gene expression at certain concentrations), Kolomin et al., 2011 (34 inflammation-related genes in mouse spleen, notably Bcl6). Panikratova et al., 2020 used resting-state fMRI in 52 healthy participants and found both Selank and Semax altered right amygdala to right temporal cortex connectivity.

Route dependence is a genuine finding, not a footnote. Vasil'eva et al., 2016 compared intranasal with intraperitoneal administration in BALB/c and C57BL/6 mice: anxiolytic and nootropic effects appeared only in the anxiety-prone BALB/c strain, intraperitoneal dosing increased frontal cortex GABA-receptor binding by 38 percent without NMDA change, and intranasal dosing increased NMDA binding by 23 percent without GABA change. Intranasal is the route used in all published clinical trials and is quoted at 92.8 percent bioavailability.

Pharmacokinetics are brief: detectable in blood within 30 seconds of intranasal administration, rapid peak, concentration falling within 5 to 5.5 minutes, no urinary metabolites, consistent with rapid tissue peptidase degradation. Downstream gene expression, BDNF and neurotransmitter effects far outlast plasma presence.

The dosing figures in practice are not trial-derived: no published dose-finding studies exist, and the intranasal protocol reflects clinical practice patterns and usual practice.