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Isolated in 1977 as a “sleep factor”, given an INN, then never confirmed: DSIP is the textbook case of a peptide whose name outlived its evidence.
Also known as: delta sleep-inducing peptide · emideltide (INN) · DSIP nonapeptide · Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu
Part of the Neuropeptides & signaling cluster
Overview
DSIP (delta sleep-inducing peptide, INN emideltide) is a nonapeptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, isolated from rabbit cerebral venous blood in 1977 as a candidate sleep factor. Small 1980s injection studies in insomniacs reported improved sleep, but its gene, precursor and receptor were never found and a 2006 review called the sleep hypothesis extremely poorly documented. It has never been approved anywhere and has no registered trials.
Source & context
Biological / chemical source: Synthetic nonapeptide
Primary research or clinical context: Never approved anywhere; a 1970s–80s research compound with an INN (emideltide) but no established physiological role
What DSIP is
Delta sleep-inducing peptide is a nine-residue peptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, that the Schoenenberger–Monnier group in Basel isolated from the cerebral venous blood of rabbits in 1977 and proposed as a circulating sleep-promoting factor — the “delta” refers to slow-wave sleep. It was assigned the international non-proprietary name emideltide, which is why some databases list it under that name. Its molecular formula is C35H48N10O15 and its average mass about 849 Da. Half a century later it remains a research compound: no product containing it has ever been approved, and the biology it was named for has not been confirmed.
The unresolved riddle
The clearest summary of DSIP's status is the title of a 2006 review in the Journal of Neurochemistry: “a still unresolved riddle” (Kovalzon and Strekalova). The authors note that the link between DSIP and sleep was never characterised further after the initial reports, partly because no DSIP gene, precursor protein or receptor has ever been isolated, and they judge the hypothesis of DSIP as a sleep factor to be extremely poorly documented. DSIP-like immunoreactivity does occur in hypothalamic neurosecretory nuclei across vertebrate species, but those nuclei are not particularly relevant to sleep regulation; the reviewers propose that a related, uncharacterised peptide accounts for both the immunoreactivity and the biological activity attributed to DSIP.
What the 1980s human studies reported
The human data are small and old. Schneider-Helmert (European Neurology 1984, 1986) summarised double-blind studies in insomniacs in which single injections before sleep improved sleep measures, repeated administration appeared to normalise sleep structure after four doses, and morning injections increased daytime activity while still improving night sleep; a single narcolepsy case was also described. These reports predate modern trial standards, involve small numbers, and were not replicated in larger controlled studies. Graf and Kastin's 1986 update in Peptides reviewed additional animal work on sleep, pain and withdrawal and proposed therapeutic possibilities that were not subsequently developed.
Effects beyond sleep in animals
Animal studies attributed a broad range of actions to DSIP that do not fit a single mechanism. Yehuda and Carasso (International Journal of Neuroscience 1988) listed effects on thermoregulation, heart rate, blood pressure, pain threshold and the lymphokine system, noted that the effects depend on circadian phase, and suggested DSIP might trigger peripheral preparatory changes associated with sleep onset. Tsunashima et al. (Brain Research 1990) found that DSIP and its phosphorylated analogue enhanced apomorphine-induced hypothermia in rats with an inverted bell-shaped dose–response. Such non-monotonic responses and mechanistic breadth are, in hindsight, warning signs that the observed activity may not belong to the peptide as isolated.
Where sleep science left it
In a 2003 review of the biochemical regulation of non-REM sleep, Obal and Krueger (Frontiers in Bioscience) place DSIP among four candidate sleep factors identified by classical transfer experiments — alongside uridine, oxidised glutathione and a muramyl peptide — and state that a physiological sleep-regulatory role has not been determined for any of them, in contrast to substances such as adenosine and cytokines whose roles were established by other methods. A 2024 mouse study of a yeast-expressed DSIP fusion peptide engineered to cross the blood–brain barrier (Mu et al., Frontiers in Pharmacology) shows the name still attracts research, but it tests a different molecule.
Why the name persists
DSIP has persistent search demand out of proportion to its evidence, partly because the name itself is a claim, and partly because it is sold by research-chemical vendors alongside better-documented peptides. Nothing in the literature since the 1980s supports a sleep effect in humans, and nothing identifies what DSIP does at a receptor. Anyone reading a product page for DSIP should weigh it against the 2006 review's verdict rather than the 1977 name.
| Claim | Documentation |
|---|---|
| Endogenous sleep factor | Isolated 1977; gene, precursor and receptor never found |
| Improves sleep in humans | Small double-blind injection studies in the 1980s; not replicated |
| Physiological sleep role | “Not determined” per 2003 review of sleep biochemistry |
| Approved product | None, anywhere |
Status and what this page is not
DSIP is not approved in any jurisdiction and has no registered clinical trial. Material sold as DSIP online is unlicensed and unverified. This profile summarises the historical and current literature; it is not a recommendation for or against anything and is not medical advice.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), 9 residues, linear; a phosphorylated analogue (P-DSIP) has also been studied
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Not specified
Average reference mass
Reference policy updated: 2026-10-05
- PubChem molecular record · 2026-10-01
- Molecular formula
- C35H48N10O15
- Average reference mass
- ≈ 848.8
- Receptors
- None identified. No DSIP gene or precursor protein has been isolated; DSIP-like immunoreactivity in hypothalamic nuclei may reflect a related, uncharacterised peptide
- Backbone
- Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), 9 residues, linear; a phosphorylated analogue (P-DSIP) has also been studied
- Status
- Never approved in any jurisdiction; no registered clinical trial as of September 2026
- PubChem CID: 68816
- CAS RN: 62568-57-4
- UNII: YN28Z5YZ73
Chemistry values: curated profile, PubChem · fetched 2026-10-01.
DSIP — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), 9 residues, linear; a phosphorylated analogue (P-DSIP) has also been studiedAverage reference mass: 848.8 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
Change log
Dated observations from the data pipeline (registry flags, trial footprints, identifiers) and editorial reviews of this profile.
- EditorialProfile content reviewed and updated by the editorial team.
FAQ about DSIP
What is DSIP?+
DSIP (delta sleep-inducing peptide, INN emideltide) is a nonapeptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, isolated from rabbit cerebral venous blood in 1977 as a candidate sleep factor. Small 1980s injection studies in insomniacs reported improved sleep, but its gene, precursor and receptor were never found and a 2006 review called the sleep hypothesis extremely poorly documented. It has never been approved anywhere and has no registered trials.
What Canadian product status is recorded for DSIP?+
Canadian product status for DSIP has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of DSIP?+
DSIP is commonly described as approximately 9 amino acids (Research nonapeptide (historical sleep-factor candidate)).
What is DSIP?+
Delta sleep-inducing peptide, a nonapeptide (WAGGDASGE) isolated from rabbit blood in 1977 as a candidate sleep factor. Its INN is emideltide.
Does DSIP work for sleep?+
Small double-blind injection studies in the 1980s reported improved sleep in insomniacs, but the link was never confirmed, no receptor or gene was found, and a 2006 review called the hypothesis extremely poorly documented.
Is DSIP approved?+
No, nowhere, and there is no registered clinical trial as of September 2026.
What is the sequence of DSIP?+
Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu; formula C35H48N10O15, average mass about 849 Da.
How does DSIP work?+
Unknown. No receptor has been identified; animal studies reported diverse effects on temperature, heart rate, pain threshold and immune markers that do not fit one mechanism.
Further reading
- FoundationsWhat Are Research Peptides? A Clear Educational GuideLearn what “research peptides” means, how they differ from approved peptide drugs, quality markers (COA, purity), and how to study them responsibly.
- SafetyPeptide Safety and Risks: A Balanced Educational OverviewAn objective, balanced overview of what research does and does not establish about peptide risks—unknowns, purity and contamination concerns, and why unapproved compounds carry uncertainty. Not reassurance and not medical advice.
- Handling & stabilityDo Peptides Expire? Shelf Life, Degradation, and Stability SignalsHow and why peptides degrade, what shelf life means for lyophilized powder versus reconstituted solution, and the physical signs researchers watch for. Educational stability literacy.
Related peptides
References & further reading
- 1.Kovalzon et al. (2006). Delta sleep-inducing peptide (DSIP): a still unresolved riddle. J Neurochem
- 2.Graf et al. (1986). Delta-sleep-inducing peptide (DSIP): an update. Peptides
- 3.Graf et al. (1984). Delta-sleep-inducing peptide (DSIP): a review. Neurosci Biobehav Rev
- 4.Schoenenberger (1984). Characterization, properties and multivariate functions of delta-sleep-inducing peptide (DSIP). Eur Neurol
- 5.Sahu et al. (1987). Delta sleep-inducing peptide (DSIP) stimulates LH release in steroid-primed ovariectomized rats. Life Sci
- 6.Pollard et al. (2001). Delta sleep-inducing peptide. Eur J Anaesthesiol
- 7.Stanojlović et al. (2005). Antiepileptic activity of delta sleep-inducing peptide and its analogue in metaphit-provoked seizures in rats. Seizure
- 8.Tukhovskaya et al. (2021). Delta Sleep-Inducing Peptide Recovers Motor Function in SD Rats after Focal Stroke. Molecules
- 9.Schneider-Helmert (1984). DSIP in insomnia. European Neurology
- 10.Schneider-Helmert (1986). DSIP in sleep disturbances. European Neurology
- 11.Yehuda & Carasso (1988). DSIP — a tool for investigating the sleep onset mechanism: a review. International Journal of Neuroscience
- 12.Obal & Krueger (2003). Biochemical regulation of non-rapid-eye-movement sleep. Frontiers in Bioscience
- 13.Mu et al. (2024). Pichia pastoris secreted peptides crossing the blood-brain barrier and DSIP fusion peptide efficacy in PCPA-induced insomnia mouse models. Frontiers in Pharmacology
- 14.PubChem — Delta sleep-inducing peptide (CID 68816)