What it is
DSIP is a short chain of nine amino acids. Its name comes from the experiments that found it: Swiss researchers reported that when they infused it into the brains of rabbits, the animals’ brain waves shifted towards “delta” waves, the slow pattern seen in deep sleep. Its official generic name is emideltide.
Nearly fifty years later its role in the body is still unclear. Nobody has found the gene that makes it or a receptor it acts on, and a natural source in humans has not been confirmed. Versions studied today are made synthetically. It is not an approved medicine in the United States.
DSIP (emideltide) is H-Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu-OH (C35H48N10O15, 848.8 g/mol, CAS 62568-57-4). Schoenenberger and Monnier (1977) reported that intraventricular infusion of the synthetic nonapeptide in rabbits enhanced delta and spindle EEG activity, while five fragments, two nonapeptide analogues and a related tripeptide did not.
No precursor gene, protein or receptor has been identified (Kovalzon and Strekalova 2006). DSIP-like immunoreactivity is found in hypothalamic neurosecretory nuclei and elsewhere, and those authors propose that an as-yet-unidentified DSIP-like peptide may account for it. Sleep-promoting activity in later rodent and rabbit work was more consistent for certain synthetic analogues than for DSIP itself. Other actions reported in animal and in-vitro studies are broad and inconsistent, including a proposed interaction with opioid systems that prompted the withdrawal studies.
Pharmacokinetics: half-life is about 2–3 minutes in rats and a monkey and 3–6 minutes in dogs after intravenous dosing (Kato et al. 1984), 5–10 minutes in human serum in vitro (Graf et al. 1987), and about 8 minutes in plasma as cited by FDA, driven by aminopeptidase cleavage from the N-terminus. A saturable transport route across the choroid plexus has been described in animals. No data exist for subcutaneous dosing.
Who made it and when
DSIP came from a laboratory in Basel, Switzerland. Marcel Monnier’s group had been studying substances in the blood of rabbits kept asleep by electrical stimulation of a deep brain region, the thalamus, since the 1960s. In 1977 Guido Schoenenberger and Monnier published its structure and showed that a lab-made copy produced the same brain-wave effect. Through the late 1970s and 1980s, researchers in Basel and Geneva gave it by vein to people with insomnia, narcolepsy and drug or alcohol withdrawal. No pharmaceutical company ever brought it to market.
Monnier’s group first described a sleep-inducing factor in rabbit cerebral venous blood collected during thalamic stimulation in the 1960s; Schoenenberger and Monnier characterised the nonapeptide and its synthetic analogue in PNAS in 1977. Kovalzon and Strekalova (2006) credit the “Schoenenberger–Monnier group from Basel” with the 1977 isolation.
Clinical work followed quickly: Schneider-Helmert, Graf and Schoenenberger reported in the Lancet (1981) that synthetic DSIP improved sleep in insomniacs, followed by further Basel studies in chronic insomnia and a single narcolepsy case (Schneider-Helmert 1984–1987). Tissot’s group in Geneva studied it in alcohol and opiate withdrawal (Dick et al. 1983 and 1984), and a German group reported an open study in opioid detoxification (Backmund et al. 1998), with study drug supplied by Strathmann AG of Hamburg. WHO assigned the INN emideltide in 1993. No marketing authorisation was found in any country, and no developer patent was verified for this article.
What the data say
In animals, the early rabbit experiments reported deeper, slow-wave sleep after DSIP, but later animal work often failed to confirm a reliable sleep effect for DSIP itself.
In people, the studies are small and old. Short courses given by vein to adults with chronic insomnia produced, at best, modest changes: one double-blind study of 16 patients concluded that the effects were weak and unlikely to be of major therapeutic value. Open studies in drug and alcohol withdrawal reported fewer symptoms, but they had no comparison group or blinding. No trial is registered on ClinicalTrials.gov, and the FDA’s 2026 review found the evidence insufficient for insomnia, narcolepsy or opioid withdrawal.
FDA (2026) counted about 209 people given intravenous DSIP (25–150 nmol/kg, 1–15 days) across published studies; none received it subcutaneously.
Chronic insomnia: Schneider-Helmert and Schoenenberger (1981) ran a randomised, double-blind, within-subject crossover in six patients (25 nmol/kg IV before bedtime), reporting fewer awakenings from the second hour onward but no change in sleep-onset latency. Schneider-Helmert (1987) gave seven nightly injections of 30 nmol/kg to 14 patients with placebo only on the first and last nights. Bes et al. (1992), in a double-blind matched-pairs parallel study of 16 patients (25 nmol/kg IV on three afternoons), found higher sleep efficiency and shorter latency, but the authors judged the effects weak, possibly driven by a change in the placebo group, and concluded that short-term treatment was unlikely to be of major therapeutic value.
Withdrawal: Dick et al. (1984) gave 25 nmol/kg IV, up to six injections daily, to 107 inpatients (60 opiate, 47 alcohol) in an uncontrolled open study and reported marked improvement in most evaluable patients, with anxiety slower to resolve and insomnia often recurring. Backmund et al. (1998) treated seven patients (35 nmol/kg IV); only two completed the schedule. Narcolepsy data consist of a single case report.
Regulatory picture
Approval: no medicine containing DSIP is approved by the FDA. Compounding: in September 2023 the FDA put it in “Category 2”, the group of substances pharmacies should not compound from, citing possible immune reactions, impurities and a lack of safety information. By April 2026 the FDA listed it as withdrawn from that category by its nominators, and FDA staff reviewed it for insomnia, narcolepsy and opioid withdrawal. In July 2026 an FDA advisory committee voted narrowly against adding it to the list of allowed compounding ingredients, agreeing with FDA staff. It is the only one of the seven peptides discussed at that meeting that the committee rejected. Enforcement: a 2020 FDA warning letter to a compounding pharmacy named DSIP among ingredients it should not have compounded.
Approval: none, and no US IND-stage programme could be verified.
Compounding: “Emideltide (DSIP)” entered Category 2 of the interim 503A policy on 2023-09-29, with FDA citing immunogenicity risk, peptide-related impurities and API-characterisation complexity. FDA’s safety-risk page (updated 2026-04-22) lists it among substances withdrawn by the nominators. It is not on the 503A bulks list (21 CFR 216.23), so this article records compounding status as unknown.
FDA’s 2026 briefing document evaluated emideltide free base and acetate for opioid withdrawal, chronic insomnia and narcolepsy. It judged neither form well characterised (non-standard naming, missing impurity, aggregate, endotoxin and bioburden data), noted the very short half-life and absence of subcutaneous data, and found the clinical studies too small, unblinded or inconsistently reported to establish effectiveness; FDA-approved therapies exist for all three conditions. On 2026-07-24 the Pharmacy Compounding Advisory Committee voted against inclusion; published accounts give the tally as 6 yes, 7 no and 1 abstention, and official minutes had not been posted when this was written.
