Entry 0023Rev 1.0Nonapeptide

DSIP

Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu · C35H48N10O15

Reviewed

2 Nov 2026

Scientific editor

[Name, PhD]

References

16 sources

DSIP is a nine-residue peptide isolated in 1977 from the blood of rabbits during electrically induced sleep, by Schoenenberger and Monnier in Basel. Its name records what it was first reported to do: increase delta-wave sleep in rabbits.1,2

Fifty years on, no gene, precursor or receptor for it has been found, and its sleep effect has not held up across laboratories. A 2006 review called it "a still unresolved riddle".9 Its generic name is emideltide.

Residues

9

Avg mass

848.8 g/mol

Sleep effect

Inconsistent

Licensed

Nowhere

01

Identity

Value
SequenceTrp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), free acid
Generic nameEmideltide (INN)
FormulaC35H48N10O15
Avg mass848.8 g/mol
CAS62568-57-4
OriginRabbit cerebral venous blood, 1977
Gene or receptorNone identified
02

History

  1. Isolated and characterised from rabbit blood collected during induced sleep; synthetic and native forms compared.1,2,3

  2. First report of effects in people, described as "multifunctional" beyond sleep.5

  3. Review summarises claims in rabbits, rats, mice and people, and a U-shaped activity curve.4

  4. In rats, DSIP itself does not increase sleep, while D-amino-acid analogues do. Same year: an uncontrolled study in 18 people with insomnia.7,8

  5. Review concludes the sleep-factor hypothesis is "extremely poorly documented".9

  6. FDA places emideltide in category 2 of its compounding list, substances with significant safety risks.13

  7. FDA advisory committee votes 6 to 7 against adding it to the list of substances pharmacies may compound.14,15

03

What the studies measured

The animal rows show why the name is doubtful: the clearest sleep effects came from altered versions of the peptide, not the natural one. The human rows are small, old, and from one group.

StudyModelWhat was measuredFindingSource
Schoenenberger 1977RabbitsEEG delta activity after infusionDelta activity rose with native and synthetic peptide[1],[3]
Obál 1986Rats24-hour sleep after injection into the brainDSIP itself did not increase sleep; D-amino-acid analogues did[8]
Susić 198710 catsSleep latency and stages over 8 hoursShorter latency, more slow-wave sleep, no change in REM[10]
Dick 1984107 patients in alcohol or opiate withdrawal, open-labelClinician-rated symptomsImprovement reported; no control group[6]
Schneider-Helmert 198618 people with chronic insomnia, one weekSleep recordingsSleep reported to normalise; not placebo-controlled[7]
Vgontzas 1995People with sleep apnoea, narcolepsy and controlsDSIP-like immunoreactivity in bloodNo difference between groups[12]
04

Regulatory and sport status

As of this revision. General information, not legal advice.

WhereStatus
UK, EUNo marketing authorisation found.
USNot approved. Placed in the FDA's significant-safety-risk category in 2023, later recorded as nominated but withdrawn; in July 2026 an advisory committee voted narrowly against allowing pharmacy compounding.13,14,15
SportNot named on the 2026 WADA list. As a substance with no approval anywhere, it falls under class S0.16
05

Open questions

  1. Whether DSIP exists in the body at all. No gene, precursor or receptor has been found, and the "DSIP-like" signal in tissue may be a different molecule.9
  2. Why altered versions promote sleep in rodents when the natural peptide does not: rapid breakdown, or a different active structure.8,9
  3. Whether any 1980s human finding survives a placebo-controlled trial. None has been published.
06

Common questions

Does DSIP induce sleep?

In rabbits in 1977, yes. Since then the effect has been inconsistent: in rats the natural peptide did not increase sleep while altered versions did, and a 2006 review called the sleep hypothesis poorly documented.

Is DSIP made in the body?

Nobody knows. No gene, precursor protein or receptor for it has been identified in almost fifty years.

What is emideltide?

The international generic name for DSIP.

Has DSIP been tested in people?

In small studies in the 1980s, mostly from one group, for insomnia and withdrawal symptoms. None was placebo-controlled.

Is DSIP banned in sport?

It is not named on the 2026 WADA list, but as an unapproved substance it falls under class S0.

—

See also

Selank Entry 0011Semax Entry 0012Nootropic Shelf
07

References

  1. Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proc Natl Acad Sci USA. 1977;74(3):1282–1286. PMID 265572
  2. Schoenenberger GA, et al. A naturally occurring delta-EEG enhancing nonapeptide in rabbits. X. Final isolation, characterization and activity test. Pflugers Arch. 1977;369(2):99–109. PMID 560681
  3. Monnier M, et al. The delta sleep inducing peptide (DSIP). Comparative properties of the original and synthetic nonapeptide. Experientia. 1977;33(4):548–552. PMID 862769
  4. Graf MV, Kastin AJ. Delta-sleep-inducing peptide (DSIP): a review. Neurosci Biobehav Rev. 1984;8(1):83–93. PMID 6145137
  5. Schneider-Helmert D, Schoenenberger GA. Effects of DSIP in man. Multifunctional psychophysiological properties besides induction of natural sleep. Neuropsychobiology. 1983;9(4):197–206. PMID 6689058
  6. Dick P, et al. DSIP in the treatment of withdrawal syndromes from alcohol and opiates. Eur Neurol. 1984;23(5):364–371. PMID 6548969
  7. Schneider-Helmert D. Efficacy of DSIP to normalize sleep in middle-aged and elderly chronic insomniacs. Eur Neurol. 1986;25(6):448–453. PMID 3792404
  8. Obál F Jr, et al. Structure-activity relationship in the effects of delta-sleep-inducing peptide (DSIP) on rat sleep. Pharmacol Biochem Behav. 1986;24(4):889–894. PMID 3754970
  9. Kovalzon VM, Strekalova TV. Delta sleep-inducing peptide (DSIP): a still unresolved riddle. J Neurochem. 2006;97(2):303–309. PMID 16539679
  10. Susić V, Masirević G, Totić S. The effects of delta-sleep-inducing peptide (DSIP) on wakefulness and sleep patterns in the cat. Brain Res. 1987;414(2):262–270. PMID 3620931
  11. Augustijns PF, Borchardt RT. Transport and metabolism of delta sleep-inducing peptide in cultured human intestinal epithelial cell monolayers. Drug Metab Dispos. 1995;23(12):1372–1378. PMID 8689946
  12. Vgontzas AN, et al. Delta sleep-inducing peptide in normal humans and in patients with sleep apnea and narcolepsy. Peptides. 1995;16(6):1153–1156. PMID 8532601
  13. Alliance for Pharmacy Compounding. 503A categories update for September 2023, summarising the FDA's category changes of 29 September 2023. a4pc.org
  14. US Food and Drug Administration. Pharmacy Compounding Advisory Committee, 23–24 July 2026: evaluation of emideltide-related bulk drug substances. fda.gov
  15. Snow CD, et al. The PEPTIDE-L wave rolls on: PCAC adds two more bulk drug substances for the 503A list. FDA Law Blog, 28 July 2026. thefdalawblog.com
  16. World Anti-Doping Agency. The 2026 Prohibited List (in force 1 January 2026). wada-ama.org Class S0.

Peptidarium Library. DSIP (entry 0023), revision 1.0, 2 November 2026. peptidarium.com/library/dsip

08

Revision history

RevDateChangeBy
1.02 Nov 2026Entry created.[Scientific editor]

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