Selank is a synthetic heptapeptide analog of the naturally occurring immunomodulatory peptide tuftsin, with an additional Pro-Gly-Pro sequence for enhanced stability. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, research has investigated its anxiolytic, nootropic, and immunomodulatory properties. Studies suggest effects on BDNF expression and monoamine neurotransmitter balance.

Semax is a synthetic heptapeptide derived from the N-terminal fragment of adrenocorticotropic hormone (ACTH 4-10) with a C-terminal Pro-Gly-Pro modification for enhanced stability. Originally developed as a neuroprotective agent, research has investigated its cognitive-enhancing, neuroprotective, and neurotrophic properties. Studies suggest effects on BDNF, NGF, and various neurotransmitter systems.