Delta Sleep Inducing Peptide Recovers Motor Function in SD Rats after Focal Stroke DSIP (Delta SleepInducing Peptide) is a naturally occurring neuropeptide first isolated in 1974. It's best known for its potential role in regulating sleep, stress, and neuroendocrine function. Here's a clear breakdown of Is DSIP Delta Sleep Inducing Peptide Safety?_Chemicalbook Frontiers Pichia pastoris secreted peptides crossing the blood brain barrier and DSIP fusion peptide efficacy in PCPA induced insomnia mouse models