Selank is a synthetic seven-amino-acid peptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). It is structurally derived from the naturally occurring immunomodulatory peptide tuftsin, with a Pro-Gly-Pro extension designed to improve metabolic stability.

Laboratory research has investigated Selank in relation to GABAergic neurotransmission, enkephalin metabolism, gene expression, neurotrophic signaling, and immune-related pathways. Preclinical studies have also examined its effects on inflammatory gene expression and other cellular signaling processes.

The available evidence remains limited, with much of the research originating from Russian laboratories and a substantial portion involving preclinical models. Selank is not FDA-approved for human use, and its mechanisms, pharmacokinetics, long-term safety, and clinical effectiveness require further independent research.