DSIP: The Peptide Named After an Effect It Struggles to Reproduce
Isolated during sleep research in the 1970s, named for the experiment rather than a mechanism, and still without an identified receptor.
DSIP has one of the odder histories in peptide research. It was isolated in the 1970s from the blood of rabbits whose brains were being electrically stimulated into slow-wave sleep, named for what the researchers were looking at, and then spent fifty years failing to behave like a sleep peptide in any simple way.
Everything below describes published preclinical and in-vitro research. It is not a therapeutic claim, not medical advice, and not a statement about effects in humans.
What it is
DSIP — delta sleep-inducing peptide — is a nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, about 849 Da. It was first described by Schoenenberger and Monnier in Switzerland, isolated from cerebral venous blood during induced delta-wave sleep.
The name is the problem. It was assigned on the basis of the experimental setup, not on an established mechanism, and the literature that followed has never converged on one. Fifty years on, DSIP is better described as a peptide found during sleep research than as a peptide that induces sleep.
Reported themes
- Sleep architecture — the original line of work, with studies describing changes in slow-wave sleep proportion in animal models. Results across studies are notably inconsistent, which is unusual for a compound this old.
- Neuroendocrine signalling — a larger and more consistent body of work describes effects on corticotropin and somatotropin release.
- Stress models — published studies examine responses to physical and chemical stressors.
- Circadian and thermoregulatory work — a smaller literature on body temperature rhythm.
No receptor for DSIP has been definitively identified, which is the central open question in this literature and the reason the mechanistic picture stays vague where other peptides have sharpened.
Practical notes
| Sequence | Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu |
|---|---|
| Length | 9 amino acids |
| Molecular weight | ~849 Da |
| Isolated | 1970s, from cerebral venous blood |
| Known receptor | None identified |
| Typical vial size | 5 mg |
One handling note specific to this sequence: it opens with tryptophan, which is among the residues most susceptible to oxidation and to photodegradation. DSIP is a compound where keeping the vial out of direct light is not generic advice — it is the residue chemistry.
Reading this literature critically
- The inconsistency across sleep studies is the honest headline. A compound named for an effect that later work struggles to reproduce is a compound whose name is doing more work than its data.
- DSIP is not an approved medicine in the European Union or anywhere else.
- Much of the foundational work predates modern analytical standards, and purity of the material used in older studies is often not documented.
- With no identified receptor, mechanistic claims in secondary sources are generally extrapolation rather than reporting.
Handling
Supplied as lyophilised powder. Stable at room temperature as a powder; refrigerate after reconstitution and protect from light more carefully than usual because of the tryptophan. Our storage notes cover oxidation and photodegradation, and the reconstitution calculator handles the arithmetic.
Every batch is analysed by an independent laboratory for HPLC purity and mass-spectrometric identity, with batch-matched certificates available on request. See the DSIP 5mg product page, or the rest of cognitive and neuro research.
All products and information referenced are for in-vitro research and laboratory use only. Nothing here is medical advice, and no therapeutic claim is made or implied.