DSIP peptide.
Nine amino acids. Forty-plus years of sleep research.

Delta sleep-inducing peptide — DSIP — is a nine-residue neuropeptide isolated from rabbit brain in 1977 by Schoenenberger and Monnier at the University of Basel. Named for its effect on slow-wave (delta) EEG activity, DSIP has been studied for sleep modulation, stress response regulation, pain attenuation, and opioid withdrawal over more than four decades. The mechanism remains incompletely characterized, the research literature is deep but uneven, and the peptide occupies an unusual position among research peptides for having both genuine clinical study and persistent mechanistic mystery.

SequenceWAGGDASGE
Length9 amino acids
Isolated1977 (Basel)
Primary study areaSlow-wave sleep
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What DSIP actually is

DSIP is a nine-amino-acid peptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE in single-letter notation). It was first isolated from rabbit brain by Guy Schoenenberger and Marcel Monnier at the University of Basel in 1977, identified while the researchers were studying substances transferable between sleeping and awake animals that modulated EEG activity. DSIP specifically increased delta-band EEG power — the slow-wave activity that characterizes deep NREM sleep — which is where its name comes from. In the decades since, DSIP has been investigated for sleep modulation, stress attenuation, pain modulation, opioid withdrawal mitigation, and broader neuroprotective effects. Its mechanism is still incompletely understood, which is unusual for a peptide with this much research history.

The short version

DSIP at a glance

FactDetail
Amino acid sequenceTrp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE). Nine residues, molecular weight approximately 849 g/mol.
Research heritageIsolated from rabbit brain by Guy Schoenenberger and Marcel Monnier at the University of Basel in 1977. The discovery came from cerebral dialysate studies examining sleep-active substances transferable between animals. Named for the delta-band EEG effect — slow-wave activity — that characterized its action.
Primary study areasSleep modulation (particularly NREM slow-wave sleep), stress response regulation, pain modulation, opioid withdrawal mitigation, chronic fatigue syndromes, and broader neuropeptide signaling research.
Mechanism statusIncompletely understood after 45+ years of research. Evidence implicates GABAergic, adrenergic, and opioid signaling modulation, but no single primary receptor or pathway has been conclusively identified. Unlike most peptides with deep research histories, DSIP remains mechanistically ambiguous.
Regulatory status (April 2026)DSIP (Emideltide) was removed from FDA Category 2 bulk drug substances list on April 15, 2026, after the nomination was withdrawn. FDA announced intent to consult the Pharmacy Compounding Advisory Committee on July 24, 2026, regarding potential inclusion of DSIP acetate and DSIP free base on the 503A bulks list.