Circadian Research
Research Only
DSIP
Also known as: Delta Sleep Inducing Peptide, DSIP, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu
Nine-amino-acid peptide first isolated from rabbit blood in 1977. Studied in sleep and EEG research.
Research overview
Delta sleep-inducing peptide (DSIP) is a nine-amino-acid peptide (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu). Schoenenberger and Monnier isolated it from rabbit blood in Basel and reported in 1977 that, infused into the brain fluid of rabbits, the synthetic peptide increased slow-wave (delta) and spindle activity on the EEG (Schoenenberger and Monnier, PNAS 1977). Small human studies followed in the 1980s and early 1990s. Some, including studies co-authored by Schoenenberger, reported better sleep in people with insomnia, but independent double-blind studies found little difference from placebo; in a 16-patient trial the effects were weak and may partly have reflected a chance change in the placebo group (Bes et al., Neuropsychobiology 1992).
Decades on, the gene, the precursor protein and a receptor for DSIP have still not been identified, and its link to sleep is regarded as poorly documented (Kovalzon and Strekalova, 2006). How it would act, whether the form first described is what the body makes, and its long-term safety remain open questions. Supplied for laboratory research use only.
Mechanism of action
How DSIP acts is not known. No receptor for it has been identified, and the gene and precursor protein that would produce it have not been found. Small studies in healthy men gave conflicting results on whether it lowers the stress hormone ACTH, one reporting a fall and another no change.