Does DSIP induce sleep?

The 1977 work reported delta-wave EEG activity in rabbits after administration. That an effect was observed in that experiment is not the same as the effect being established, and the subsequent literature has not resolved it.

Is DSIP a natural human peptide?

It was isolated from rabbit blood. No DSIP gene has been identified in any species, so its status as an endogenous peptide remains unconfirmed.

The International Nonproprietary Name assigned to DSIP. An INN is a naming decision, not an approval.

Is DSIP approved anywhere?

No. It holds no marketing authorisation and is supplied for laboratory research only.

DSIP (Delta Sleep-Inducing Peptide)

What Is DSIP? A Research Overview

JMWritten & reviewed by Jack Muncaster · Founder, UK PeptidesLast reviewed 2026-08-234 cited sources

DSIP is a nine-residue peptide, Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, isolated from rabbit cerebral venous blood in 1977 and named for delta-wave EEG activity observed after administration. Despite the name, no DSIP gene, precursor protein or receptor has been characterised in the decades since.

Key facts

Sequence: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu
Single-letter: WAGGDASGE
Length: 9 residues (nonapeptide)
Molecular weight: 848.8 Da
Molecular formula: C35H48N10O15
CAS number: 62568-57-4
PubChem CID: 68816
INN: Emideltide
Gene / receptor: Neither identified

Where it came from

Schoenenberger, Monnier and colleagues in Basel electrically stimulated the thalamus of a sleeping rabbit, collected blood draining from its brain, and isolated a small peptide from it. Administered into the cerebral ventricles of awake rabbits, the fraction was reported to produce the slow delta-wave EEG pattern characteristic of deep sleep. The isolation was published in the Proceedings of the National Academy of Sciences in March 1977; the sequence followed in Pflügers Archiv in 1978.

The name is a hypothesis, not a finding

Delta sleep-inducing peptide describes what the discoverers believed they had found. That is normal for the era and not a criticism of the original work. It becomes a problem when the name is treated as a summary of established pharmacology, because the evidence behind it has never firmed up. A compound whose name asserts an effect will be read as having that effect, and readers rarely check whether the name was ever earned.

Research material referenced

DSIP 5mg — third-party HPLC tested

View — £13.99

What was never established

This is the central fact about DSIP and it is routinely omitted. No DSIP gene has been isolated. No precursor protein has been identified. No receptor has been characterised. For a peptide proposed as an endogenous signalling molecule, that combination is remarkable — the usual route from isolation to accepted biology runs through exactly those three things, and DSIP has completed none of them in nearly fifty years.

How the field describes it

Kovalzon's 2006 review in the Journal of Neurochemistry is titled 'Delta sleep-inducing peptide (DSIP): a still unresolved riddle'. That is a fair summary of the literature's own assessment: a peptide with a substantial body of published work — roughly 519 indexed records — that has neither been confirmed as a sleep factor nor definitively dismissed.

A species detail worth noting

The peptide was isolated from rabbit. The relationship between the rabbit sequence and any human counterpart is part of what remains unresolved, and it matters because a peptide's endogenous role in one species does not establish one in another. Without an identified gene in any species, even this question stays open.

Regulatory position

DSIP holds no marketing authorisation from the MHRA, EMA or FDA. It carries an International Nonproprietary Name, emideltide, which reflects that a name was assigned rather than that a product was approved. It is supplied for laboratory research only.

Extended research context

The DSIP (Delta Sleep-Inducing Peptide) deep dive

Deep dive: a name that was a hypothesis, not a finding

In 1977 the Schoenenberger-Monnier group in Basel electrically stimulated the thalamus of a sleeping rabbit, collected blood draining from its brain, isolated a peptide fraction, and reported that administering it into the ventricles of awake rabbits produced delta-wave EEG activity. They named it delta sleep-inducing peptide. By the standards of the time this was careful, imaginative work, and they followed it properly - the 1978 Pflugers Archiv paper reported sequence, synthesis and activity of the synthetic nonapeptide rather than stopping at a suggestive fraction. The problem is not the original research. It is that a name recording a hypothesis has been read ever since as a summary of established pharmacology, and almost nobody checks whether it was earned.

Deep dive: the three things that are missing

A proposed endogenous peptide becomes accepted biology by a recognisable route. The gene is located. The precursor protein is characterised. A receptor is identified, giving a mechanism and a testable target. DSIP has completed none of these in nearly fifty years. The receptor gap is the most disabling - without one there is no mechanism to test, no dose-response to build, no antagonist to design, and no way to establish that an observed effect runs through the proposed pathway at all. The gene gap is the hardest to explain away: modern genomics located MOTS-c inside a short open reading frame nested within the mitochondrial 12S rRNA gene, sequence already annotated as something else. That a peptide described in 1977 still has no identified gene in any genome is a substantive observation, not an accident of effort.

Deep dive: why 519 papers is not 519 confirmations

DSIP has roughly 519 indexed PubMed records - more than Selank's 135 or Semax's 231. Publication volume tracks how interesting a question is, not how well it has been answered. A tractable question generates a burst of work and then stops; a question that resists resolution generates papers indefinitely, each a further attempt rather than a further confirmation. Kovalzon's 2006 review in the Journal of Neurochemistry states the field's own assessment in its title: a still unresolved riddle. Reading any individual DSIP paper without that context invites mistaking activity for consensus.

Research applications

▸Historical study of humoral sleep-factor hypotheses
▸Electroencephalography and delta-wave research methodology
▸Structure-activity work on flexible, acidic short peptides
▸Comparative work on peptides lacking identified receptors
▸Analytical method development for tryptophan-containing peptides

Handling checklist

✓Store lyophilised material cold, dry and protected from light
✓No reducing agent needed — the sequence contains no cysteine
✓No methionine oxidation to expect; a +16 Da satellite warrants explanation
✓Protect from prolonged light — the single tryptophan is mildly photosensitive
✓Expect pH-dependent solubility; the peptide is strongly acidic with no basic residue
✓Aliquot to avoid repeated freeze-thaw cycles

Common research-handling mistakes

Learnt from thousands of researcher orders across our UK labs.

✗ Treating the name as evidence of the effect

Fix: The name records a 1977 hypothesis from a single rabbit EEG study. It is not a summary of established pharmacology.

✗ Citing the 1977 paper as proof DSIP induces sleep

Fix: It reports delta-wave EEG activity in rabbits after intraventricular administration — a narrower claim than inducing sleep, in one species, by a route that bypasses every normal barrier.

✗ Assuming DSIP is an established endogenous human peptide

Fix: No gene has been identified in any species, no precursor characterised and no receptor found.

✗ Reading 519 papers as 519 confirmations

Fix: Volume reflects an unresolved question attracting sustained attempts, not accumulated confirmation.

✗ Making any sleep claim about supplied material

Fix: The evidence does not support it and a therapeutic claim about research material is what MHRA enforcement targets.

Continue researching

Peer-reviewed guides, comparators and matched reference materials.

Frequently asked questions

Does DSIP induce sleep?: The 1977 work reported delta-wave EEG activity in rabbits after administration. That an effect was observed in that experiment is not the same as the effect being established, and the subsequent literature has not resolved it.
Is DSIP a natural human peptide?: It was isolated from rabbit blood. No DSIP gene has been identified in any species, so its status as an endogenous peptide remains unconfirmed.
What is emideltide?: The International Nonproprietary Name assigned to DSIP. An INN is a naming decision, not an approval.
Is DSIP approved anywhere?: No. It holds no marketing authorisation and is supplied for laboratory research only.

Primary sources & clinical trials

Peer-reviewed research and registered trials from PubMed, ClinicalTrials.gov, PubChem, FDA and NIH. All links open in a new tab and point to the primary source, so every claim can be verified at origin.

Written and reviewed by

Jack Muncaster · Founder, UK Peptides

Jack founded UK Peptides in Manchester after repeatedly receiving research compounds with missing or recycled paperwork. He is responsible for supplier selection, batch release decisions and the content published in this research library. Every article here is sourced to primary literature and every product page to a signed third-party certificate.

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