DSIP

DSIP was isolated in 1977 from cerebral venous blood of rabbits whose brains had been electrically stimulated to induce sleep ^[1][2]. The Basel group led by Schoenenberger and Monnier determined its sequence as Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu and showed that the synthetic peptide, infused into rabbit brain ventricles, increased delta (slow-wave) EEG activity by about 35% compared with controls ^[2].

Despite its name, DSIP has never been firmly established as a natural sleep factor. A 2006 review noted that no gene, precursor protein or specific receptor for DSIP had been identified, and described the evidence that it regulates sleep as “extremely poorly documented” ^[3]. DSIP is now sold by research peptide vendors for sleep, a use not supported by modern trials.

How DSIP acts is not known. Researchers have proposed that it modulates the body’s opioid systems and influences stress hormones such as cortisol, describing a “programming” rather than a directly sedating action ^[7]. In the first human study, sophisticated EEG and behavioural analyses found no classic sedation even though participants slept more ^[4]. The 2006 review proposed that a still-unidentified DSIP-like peptide may explain the DSIP-like activity measured in tissues ^[3].

DSIP is broken down quickly in blood: when incubated in human or rat blood it released tryptophan-like fragments, and the authors concluded that the rapid disappearance of injected DSIP was due to degradation ^[8].

In rabbits, the synthetic peptide enhanced delta and spindle EEG activity ^[2]. Beyond sleep, researchers reported effects on stress responses and interactions with opioids and other drugs, mostly in animals ^[7]. These remain hypotheses rather than established effects, and the 2006 review concluded that DSIP’s biological role is still obscure ^[3].

The first human study, in six healthy volunteers, gave DSIP by slow intravenous infusion in a double-blind crossover design; total sleep in the following 130 minutes rose by a median of 59% compared with placebo, with no side effects observed ^[4].

Later independent double-blind trials were less encouraging. In a study of 16 people with chronic insomnia, DSIP produced slightly higher sleep efficiency and shorter time to fall asleep, but the effects were weak, partly explained by changes in the placebo group, and subjective sleep quality did not improve; the authors concluded DSIP was unlikely to be of major benefit ^[5]. A crossover study in insomniacs found that sleep improvements under DSIP were not significantly different from placebo or baseline, and judged them of little clinical significance ^[6].

A 1984 pilot study in seven patients with chronic pain conditions reported reduced pain in six after intravenous DSIP, but had no control group ^[7]. In a 2009 randomised study in 24 women having anaesthesia, DSIP unexpectedly lightened rather than deepened anaesthesia and increased heart rate ^[9].

The insomnia and volunteer studies used 25 nmol/kg by intravenous infusion ^[4][5][6]. The anaesthesia study gave intravenous bolus doses of 25, 50 or 100 nmol/kg ^[9]. In rabbits, 6 nmol/kg was infused into the brain ventricles ^[2]. All human doses were given intravenously under supervision; these are study doses, not recommendations.

The small early studies reported DSIP as well tolerated ^[4], but the total number of people studied is small and follow-up was short. In the anaesthesia study DSIP increased heart rate and reduced heart rate variability ^[9]. The US FDA’s compounding page (as of April 2026) lists emideltide (DSIP) among substances previously placed in its category of bulk substances that may present significant safety risks, citing possible immunogenicity and difficulties with peptide-related impurities and characterisation; the nomination was later withdrawn ^[10].

DSIP is not approved as a medicine in the UK, US, Canada, Australia or New Zealand, and we found no approval elsewhere. See our legal status overview and the UK page.

Research DSIP is usually sold as a freeze-dried powder. Because DSIP degrades quickly in blood ^[8], its stability in solution should not be assumed; see our peptide storage guide and the bacteriostatic water guide.

You can compare prices, learn how to read a COA, and see our list of third-party tested suppliers. Other neuropeptides sold as research compounds include Selank and Semax.