Selank is a synthetic peptide derived from the natural peptide Tuftsin, which is responsible for stimulating the immune system. However, Russian scientists who developed Selank designed it to treat anxiety and improve cognitive function, not for immune enhancement. Unfortunately, there is limited clinical data on its effects, and it has never been approved for human use, so most of what we know comes from anecdotal reports.
Recently, Selank has gained popularity alongside Semax, as both peptides share similar properties and are often used together to enhance their effects.