What Is DSIP (Delta Sleep-Inducing Peptide)?

DSIP — delta sleep-inducing peptide — is a nonapeptide first isolated in 1977 from the cerebral
venous blood of rabbits. The name records the experimental observation that led to its discovery, not an established
function, and the literature that followed has been notably inconsistent.

Product page: DSIP.

Identity

PubChem catalogues DSIP under CID 68816 with the molecular formula
C₃₅H₄₈N₁₀O₁₅ and a molecular weight of approximately 848.8 g/mol. Its
sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu — nine residues, hence “nonapeptide”.

Discovery and naming

Schoenenberger and Monnier characterised the peptide in a 1977 paper in the Proceedings of the National Academy of
Sciences, working from material obtained during slow-wave induction experiments in rabbits. A companion paper by
Monnier and colleagues compared the properties of the original isolate with a synthetic nonapeptide.

The “delta sleep-inducing” label comes from the electroencephalographic endpoint used in those
experiments. It is a descriptor attached at discovery, and it should be read as such rather than as a summary of what
the peptide has been shown to do.

Research areas and the state of the evidence

Graf and Kastin’s 1986 update in Peptides remains the most useful entry point to the older literature.
It is worth reading precisely because it documents how uneven the findings were: the review covers a wide span of
reported activities, and the picture that emerges is of a peptide investigated across many endpoints without a settled
mechanism.

Research has touched on electroencephalographic patterns, neuroendocrine and hypothalamic-pituitary-adrenal axis
measures, and various stress-response endpoints in animal models. Reported effects have been variable between
laboratories, and DSIP has not accumulated the kind of consistent, replicated evidence base that would support firm
mechanistic claims.

Terminology note

In the literature DSIP appears both as the free nonapeptide and in phosphorylated and other modified forms. Papers do
not always state which was used. When recording work with this material, the specific form matters and should be
documented explicitly.

For broader categorisation, DSIP is grouped with other neuropeptide research materials in this catalog such as
Semax and Selank. That grouping is taxonomic — these
are peptides studied in central nervous system research contexts — and implies nothing about shared mechanisms or
comparable effects.

Research use only

Supplied strictly for in-vitro laboratory research. This page describes identity, discovery and research history. It
is not sleep advice, contains no dosing or administration information, and makes no treatment claims.

References

Schoenenberger G.A., Monnier M. (1977). Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proc Natl Acad Sci U S A, 74(3):1282–6. PMID 265572.

Monnier M. et al. (1977). The delta sleep inducing peptide (DSIP). Comparative properties of the original and synthetic nonapeptide. Experientia, 33(4):548–52. PMID 862769.

Graf M.V., Kastin A.J. (1986). Delta-sleep-inducing peptide (DSIP): an update. Peptides, 7(6):1165–87. PMID 3550726.

PubChem. Delta Sleep-Inducing Peptide — Compound Summary, CID 68816. National Library of Medicine.