Particle DSIP (Delta Sleep Inducing Peptide) DSIP is a naturally occurring neuropeptide that has attracted the attention of researchers for decades due to its association with sleep cycles, neuroendocrine mechanisms, and DSIP Peptide: Sleep Cycles and Neurobiological Adaptation Research NORTHEAST NOW Delta Sleep Inducing Peptide Discography: Vinyl, CDs, & More Discogs DSIP (10ml) in solution delta sleep inducing peptide.