Delta sleep-inducing peptide (DSIP) is a nine-amino-acid peptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, first isolated in 1977 from the cerebral venous blood of rabbits during experimentally induced sleep. It was named for the slow, high-amplitude delta waves it was associated with on the EEG.
Nearly fifty years later DSIP remains one of the more puzzling peptides in neuroscience. It has a large early literature, but no gene, precursor protein or dedicated receptor for it has ever been identified, and that shapes how its research should be read.
At a glance
| Also known as | DSIP, emideltide |
| Sequence | Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE) |
| Length | 9 residues |
| Molecular weight | ≈849 Da |
| Discovered | 1977, Schoenenberger and Monnier (Basel) |
| Receptor | None identified |
| US status | Not FDA-approved; research use only |
How it was discovered
Guido Schoenenberger and Marcel Monnier collected cerebral venous blood from rabbits in which sleep had been induced by electrical stimulation, then infused fractions of it into the brain ventricles of recipient rabbits. A fraction that increased delta and spindle activity on the EEG led them to a nonapeptide.
In their 1977 paper they synthesized nine candidate peptides and tested them double-blind by intraventricular infusion in 58 rabbits. Only the synthetic peptide with the DSIP sequence reproduced the delta and spindle enhancement of the original material.
The receptor problem
For most signaling peptides the story runs from gene to precursor to receptor. DSIP breaks that pattern. No gene encoding a DSIP precursor has been confirmed, no receptor has been cloned, and there is no agreed binding site. A 2006 review in the Journal of Neurochemistry summarized the field in its title: “a still unresolved riddle.”
DSIP-like immunoreactivity has been reported in brain and peripheral tissues, but how that material relates to the synthetic nonapeptide is unclear. Without a receptor there is no established signaling pathway, so reported effects are best read as observations rather than a defined mechanism.
What the research has measured
Sleep EEG. Early studies in rabbits, rats, mice and cats measured changes in delta-band activity and sleep architecture after central or peripheral administration. A 1984 review in Neuroscience & Biobehavioral Reviews collected this work and noted that effects depended strongly on dose and timing, with a non-linear dose-response relationship.
Beyond sleep. The same review described reported effects on neurotransmitter levels in the brain, circadian and locomotor patterns, and stress-related endocrine measures. Most of these findings come from single laboratories and were not consistently replicated.
Human studies. Small clinical studies were run in the 1980s, with mixed and inconsistent results. No regulator has approved DSIP for any use.
Why the literature is hard to interpret
Several factors make DSIP results difficult to compare: the absence of a receptor, sensitivity to dose and timing, differences in route of administration between studies, and reports of rapid breakdown of the peptide in biological fluids. For researchers, that makes careful controls and verified material especially important, and it is one reason purity and identity confirmation on the certificate of analysis matters for this compound.
Handling in the lab
DSIP is supplied as a lyophilized powder. Lyophilized peptides are normally kept frozen, dry and away from light, and once reconstituted are kept refrigerated and used within a short window. See our reconstitution protocol for technique, and bacteriostatic vs sterile water for diluent choice.
Frequently asked questions
What is DSIP?
A nine-residue peptide (WAGGDASGE) isolated in 1977 and named for its association with delta-wave EEG activity in rabbits.
Does DSIP have a receptor?
None has been identified. No DSIP receptor has been cloned and no consensus binding site established, which is the main open question in this literature.
Is DSIP the same as melatonin?
No. Melatonin is a small indoleamine hormone made by the pineal gland with well-characterized receptors. DSIP is a peptide with no identified receptor.
Is DSIP FDA approved?
No. DSIP is not approved by the FDA or any other major regulator. Isla Longevity supplies it for laboratory research only.
Purity and certificates
Every batch ships with a third-party certificate of analysis, published by batch number in our COA Bank. View DSIP and its current COA. New to reading certificates? Start with how to read a certificate of analysis.
Related reading: What is Selank? · What is Semax? · How to read a COA
References
- Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proc Natl Acad Sci USA. 1977;74(3):1282–1286.
- Graf MV, Kastin AJ. Delta-sleep-inducing peptide (DSIP): a review. Neurosci Biobehav Rev. 1984;8(1):83–93.
- Kovalzon VM, Strekalova TV. Delta sleep-inducing peptide (DSIP): a still unresolved riddle. J Neurochem. 2006;97(2):303–309.
Research use only
Isla Longevity supplies this compound for laboratory research use only. It is not approved by the FDA for human or veterinary use and is not for human consumption. This article summarises published research and is not medical guidance.
