DSIP (Delta Sleep-Inducing Peptide) is a synthetic nonapeptide (sequence: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) originally isolated from rabbit cerebral venous blood. Supplied for research use only in laboratory studies of neuronal signaling, sleep-related EEG activity models, and neuroendocrine pathways. Not for human or veterinary use.