Selank

Selank is a synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro, built on tuftsin (Thr-Lys-Pro-Arg), a fragment of the heavy chain of immunoglobulin G. The added C-terminal Pro-Gly-Pro sequence slows enzymatic degradation. Selank was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and is registered in Russia as intranasal drops.

Selank is a bulk drug substance with no FDA-approved product. No FDA-labeled indication or dose exists. Human data come mainly from Russian clinical literature and are limited in size and design.

No FDA-labeled indication exists. In Russia, selank nasal drops are registered for anxiety-related and asthenic conditions. Prescribers in the US use compounded intranasal preparations of selank for purposes they determine.

The mechanism is not fully characterized and rests mainly on preclinical data. Animal and in vitro studies report allosteric modulation of GABA-A receptor binding, changes in serotonin and dopamine turnover, increased hippocampal BDNF expression, inhibition of enkephalin-degrading peptidases, and effects on cytokine expression such as interleukin-6. How these findings translate to human effects has not been established.

Formal human pharmacokinetic data are limited. Selank is intended for intranasal use because peptides are degraded in the gut; it is absorbed across the nasal mucosa. In blood it is rapidly cleaved by peptidases, with a plasma half-life of minutes, and some of its fragments retain activity in animal models. Distribution, metabolism and elimination in humans have not been characterized in controlled studies.

• Hypersensitivity to selank or any excipient.
• Not for use in pregnancy, lactation or patients under 18 (no safety data; Russian labeling lists these).

• Limited safety data: no controlled US trials define the adverse-effect profile, long-term safety or abuse potential.
• Psychiatric conditions: use caution in patients with severe or unstable psychiatric illness, and reassess if mood or behavior worsens.
• Hepatic or renal impairment: no data; use caution.
• Compounded preparation: strength, excipients and preservative vary by formulation; confirm the specific preparation prescribed.

No formal drug interaction studies exist. Preclinical reports suggest selank may modify the effects of benzodiazepines. Additive CNS effects are possible with benzodiazepines, other sedative-hypnotics, alcohol, antidepressants and antipsychotics; monitor when combined.

Reported adverse effects are mainly local and include nasal irritation, dryness or burning. Headache, fatigue and dizziness have been reported. Hypersensitivity reactions are possible with any peptide. Frequencies are not established.

Not recommended. No human or adequate animal data establish safety in pregnancy or breastfeeding, and Russian labeling lists both as contraindications.

Assess symptoms, mood and any change in psychiatric status at follow-up, along with nasal tolerability and signs of hypersensitivity. Review concomitant CNS-active medicines.

• Selank, PubChem Compound Summary, National Library of Medicine.
• USP General Chapter <795> Pharmaceutical Compounding: Nonsterile Preparations.