DOSAGE IN STUDIES
Selank Dosage: Protocols and Half-Life in the Research Literature
Russian intranasal protocols cluster at 300-900 microg/day across 7-14 days. Rodent IP and intranasal studies use 100-500 microg/kg. None of this is a human recommendation.
Selank Dosage in Anxiolytic Studies
Selank dosage for anxiety in the Russian clinical record converges on a narrow band. The Zozulia (2008) trial used intranasal Selank for fourteen days in 62 generalized anxiety and neurasthenia patients, with doses typical of the broader Russian pharmacopoeia range — roughly 300-900 microg per day in adults, divided across two or three intranasal administrations [1].
The rationale for divided dosing is mechanistic. Intact peptide clears plasma in minutes; an intranasal split-dose schedule keeps cortical and hippocampal exposure topped up across the waking day without inducing sedation [11]. The 7-14 day course length is the canonical Russian protocol — long enough for cumulative BDNF and gene-expression effects to develop, short enough that long-term tolerance and dependence questions remain uncharacterized in the published record.
REPORTED RESEARCH PROTOCOLS
Reported Research Protocols
The Selank peptide protocol literature breaks into three tiers by study type.
Human clinical (Russian only): 300-900 microg/day intranasal in adults, divided across 2-3 administrations, 7-14 day course [1][10].
Rodent anxiolytic / behavioral: 100-300 microg/kg single intraperitoneal injection for acute open-field and forced-swim work [3][17].
Rodent neurotrophic / cognitive: 250-500 microg/kg intranasal for BDNF mRNA and protein readouts [4]; 0.3 mg/kg/day IP for seven days for the ethanol-induced memory protection and BDNF normalization work [5].
Routes studied in the published literature: intranasal (the clinical formulation and most preclinical CNS work), intraperitoneal (the workhorse rodent route), and subcutaneous (limited preclinical use).
These figures describe what investigators administered to which species at which dose by which route. They are not human dosing recommendations. Selank is not approved for human use outside the Russian Federation.
Dosing frequency in trials
Russian clinical protocols have used 7-14 day daily courses across the anxiety and neurasthenia literature [1]. Chronic indefinite dosing is not characterized in the published record. The single 14-day Zozulia trial is the longest controlled human exposure documented in English-PubMed-indexed literature, and the 2008 immunomodulatory paper used the same 14-day window [10].
DOSE TIMING
Dose timing
Russian protocols typically split daily doses morning and midday given the short plasma half-life and the absence of a sedative profile. The pharmacokinetic rationale: intact Selank clears plasma within minutes, but the downstream BDNF mRNA peak at three hours and protein peak at twenty-four hours decouple subjective effect timing from peptide elimination [4]. A morning-and-midday split mirrors the Russian-trial dosing pattern; later-day dosing has not been characterized for sleep effects in controlled human work.
REPORTED RESEARCH DOSES
Reported research doses
Russian trial doses cluster around 300-900 microg/day intranasal in adults. This is a research-framing description of what trial protocols administered, not a human recommendation. Selank is not FDA approved, not EMA approved, and not MHRA approved; in the United States it is sold strictly as a research chemical.
Selank Half-Life
The Selank half-life story is two-layered, and the two layers move on different clocks.
Layer one is intact peptide in plasma. Reports cite roughly two to three minutes in rodents, reflecting rapid carboxypeptidase action [11]. The Pro-Gly-Pro tripeptide bolted onto the tuftsin C-terminus was specifically introduced to slow that degradation relative to native tuftsin — and it does, but not enough to keep intact peptide circulating for long [11].
Layer two is downstream effect. Hippocampal BDNF mRNA rises at three hours and BDNF protein at twenty-four hours after a single 250-500 microg/kg intranasal dose in rats [4]. Enkephalinase inhibition extends leu-enkephalin half-life for the duration of the inhibitor's presence at the target [2]. Gene-expression shifts persist for hours to days.
The practical implication: dosing frequency in Russian protocols is anchored to downstream effect, not to intact-peptide plasma kinetics. Two or three intranasal administrations per day is the standard pattern.
DURATION OF EFFECT
Duration of effect
Plasma half-life is short — minutes-scale — but downstream gene-expression changes persist beyond detectable peptide levels in rodent models. The BDNF mRNA / protein cascade documented at 3 and 24 hours is the longest-running directly-measured downstream effect in the rodent literature [4]. Behavioral effects in the rat forced-swim and open-field assays are reported within thirty minutes of injection and last through the assay window [8][17].
Common research protocols
Most cited Selank peptide protocol references use 7-14 day intranasal courses at 300-900 microg/day across two or three administrations [1]. The morphine-withdrawal and alcohol-withdrawal rodent studies used IP routes at comparable per-kilogram doses to the anxiolytic work [12][13]. The BDNF protein-synthesis blockade work used the 0.3 mg/kg/day IP for seven days schedule [5][16].