DSIP, delta sleep-inducing peptide, is the nonapeptide Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, mass 848.8, first isolated from the cerebral venous blood of rabbits during electrically induced sleep and sequenced by Monnier and Schoenenberger's group in 1977. Its name records what the discoverers were looking for. What the evidence supports is narrower: EEG changes in rabbits after infusion, transport across the rabbit blood-brain barrier, and a long tail of animal studies on stress and endocrine readouts, none of which has produced a receptor. This post gives the sequence and identifiers, sets out what the founding experiments measured, states the receptor problem plainly, and reads the current certificate for the DSIP in the catalogue, which is supplied as a 5 mg lyophilized powder for laboratory research use only.
What is the sequence?
| DSIP | |
|---|---|
| Sequence | Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE) |
| Residues | 9 |
| Formula | C35H48N10O15 |
| Mass | 848.8 |
| CAS | 62568-57-4 |
| PubChem CID | 68816 |
| Termini | Free amine, free acid |
| Charge at pH 7 | About −2 (aspartate, glutamate, C-terminus, minus the N-terminus) |
Three things stand out chemically. There is no cysteine and no methionine, so nothing oxidises readily; the tryptophan at position 1 is light-sensitive over long periods, which is the one storage note. Four of the nine residues are glycine or alanine, small and flexible, so the peptide has little fixed structure in solution. And it is strongly acidic, which affects how it behaves on a reversed-phase column, as the chromatogram post explains for charged peptides generally. The sequence post covers the one-letter code.
What did the 1977 experiments actually measure?
Two papers from the same year, both in rabbits.
The EEG paper. Monnier, Dudler, Gächter and colleagues infused the peptide intravenously into rabbits and recorded the electroencephalogram and motor activity. They reported an increase in the slow-wave, delta-band activity that characterises deep sleep, which is where the name comes from. The measurement was electrical activity in an anaesthetised-then-recovering animal preparation, and the comparison was against saline.
The transport paper. Monnier and Schoenenberger reported that the synthetic peptide, given intravenously, crossed the rabbit blood-brain barrier, which was necessary for the EEG finding to make mechanistic sense.
Those two results are the foundation. Everything since has been built on them, and the trial-data post explains why a rabbit EEG in 1977 is not a result about a plate in 2026, or about any other species.
Why has no receptor been found?
Because fifty years of looking have not turned one up. The peptide has been studied in rodents, cats and rabbits for effects on sleep architecture, on stress hormones, on body temperature and on pain thresholds, and the results are inconsistent between laboratories and between species. No binding site has been characterised, no gene has been assigned, and no selective antagonist exists, which is the tool that would settle whether the reported effects share a mechanism. The product page carries this as its first caveat, and it belongs in any methods section: DSIP is a peptide with a literature of effects and no receptor.
For a research design that means the receptor table lists it without a target, the GPCR post does not apply to it, and a study using it has to be framed around a phenotype or a downstream readout rather than a binding event. It sits in the catalogue's nootropic section with Selank, which has the same problem to a lesser degree, and near the bioregulator series, epithalon and pinealon among them, whose literature has a similar shape.
What does the name promise that the evidence does not?
Sleep, in anything other than the original rabbit preparation. The name is a hypothesis from 1977 that was never confirmed as a mechanism, and it should be read as a label, not a description. A methods section that calls the compound "a sleep peptide" is citing the name; one that says "the nonapeptide WAGGDASGE, reported by Monnier et al. to increase delta-band EEG activity in rabbits" is citing the evidence. The five-names post makes the general argument that a compound's name is its least reliable identifier; DSIP is the clearest case in the catalogue.
What does the certificate report?
Lot DSIP5-0803, certificate COA7602, issued by Bioviridian Inc. on 17 August 2026 against a 5 mg sample of white lyophilized powder, published unaltered on the certificate page.
| Certificate line | Result | What it tells you |
|---|---|---|
| Identity, LC-MS/MS | DSIP, observed mass 848.8 | Matches the nonapeptide; the common analogue with phosphoserine at position 7 would read 928.8 |
| Content, HPLC quantitation | 5.21 mg | Overage against the 5 mg label |
| Purity, RP-HPLC at 214 nm | 99.72% | One main peak |
| Endotoxin | < 0.05 EU/mL | Suitable for cell work |
| Heavy metals | Conforms | August 2026 layout |
The identity line rules out the phosphorylated analogue that appears in some of the literature and some catalogues; 80 mass units is unambiguous.
How many molecules are in 5 mg?
| Vial | Moles | In 1 mL | In 2 mL |
|---|---|---|---|
| 5 mg | 5 mg ÷ 848.8 g/mol = 5.89 µmol | 5.89 mM | 2.95 mM |
The molarity post covers the arithmetic; the concentration table lists the vial with the rest of the catalogue.
How is it handled?
As an acidic, unstructured short peptide. It dissolves immediately in water or reconstitution solution, has no oxidisable sulphur, and is exposed at both termini to exopeptidases in serum-containing medium. Keep solutions dark for the tryptophan's sake and cold for everything else; the reconstituted-lifetime post gives the windows. As a dry powder it is stable under the storage guide conditions.
Frequently asked questions
Does DSIP have a receptor?
None has been definitively identified. That is the product page's first caveat and the honest state of the literature after five decades.
What did the original paper show?
Increased delta-band EEG activity in rabbits after intravenous infusion, against saline, with a companion paper showing the peptide crossed the rabbit blood-brain barrier. Both 1977.
Is the catalogue's DSIP the phosphorylated form?
No. The certificate mass, 848.8, is the unmodified nonapeptide. The phosphoserine analogue would be 80 units heavier.
Why is it shelved as a nootropic?
Because that is where buyers look for it. Its literature is sleep-architecture and stress work in animals, not cognition, and a methods section should cite the primary papers rather than the shelf.
What should the methods section record?
"DSIP (WAGGDASGE, CAS 62568-57-4)", the supplier, lot DSIP5-0803, certificate COA7602, the observed mass, the stock concentration in molar terms, and a sentence noting that no receptor has been identified. The methods-section post has the template.
References
- Monnier M, Dudler L, Gächter R, et al. Delta sleep-inducing peptide (DSIP): EEG and motor activity in rabbits following intravenous administration. Neuroscience Letters 1977;6(1):9-13. doi.org/10.1016/0304-3940(77)90057-x
- Monnier M, Schoenenberger GA. Transport of the synthetic peptide DSIP through the blood-brain barrier in rabbit. Experientia 1977;33(12):1609-1610. doi.org/10.1007/BF01934026
- PubChem, National Library of Medicine. Delta sleep-inducing peptide, CID 68816, C35H48N10O15, 848.8 g/mol, CAS 62568-57-4. Read 28 September 2026. pubchem.ncbi.nlm.nih.gov/compound/68816
Every product mentioned is sold for laboratory research use only and is not for human or animal use. Nothing on this page describes or recommends use of the material sold here in humans or animals.
