RESEARCH LOG / DELTA SLEEP-INDUCING PEPTIDE
DSIP is a nine-residue peptide studied for slow-wave sleep, the HPA axis, and chronic insomnia.
A dark, data-logged reading of the published record: the EEG findings, the small 1980s human trials, the unresolved mechanism, and the gaps the literature still leaves open.
The short version
DSIP (delta sleep-inducing peptide) is a tiny natural molecule, a chain of nine amino-acid building blocks, first found in 1977 in the blood of sleeping rabbits [1]. It is named for one thing it did in that experiment: it boosted the slow brain waves (called delta waves) that mark deep sleep. Since then, scientists have tested it for sleep, for the body's stress system, and a few other roles. The honest picture is messy. A handful of small European studies from the 1980s reported that it helped some people with long-term sleep trouble [2][7], but the results were modest and were never confirmed by large modern trials. After more than forty years, nobody has found the cell receptor it acts on, so how it works is still unknown [3]. Many people who try it report no effect at all. DSIP is not approved as a medicine anywhere. What people report, including the downsides, is on the effects page, and the studies themselves are summarized in plain English throughout this log.
What is dsip peptide
DSIP is a linear nonapeptide, a chain of nine amino acids in the order Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, with a molecular mass of 848.8 daltons (a dalton is the unit used to weigh single molecules) [1]. It was isolated by Schoenenberger and Monnier from the cerebral venous blood of rabbits whose brains had been put into an electrically induced sleep state, and infusing it into the brain produced a specific increase in delta and spindle EEG activity, the electrical signatures of deep sleep [1]. The peptide is reported to occur naturally in mammalian plasma, cerebrospinal fluid, and milk, which makes it an endogenous compound, one the body already makes, rather than a foreign drug. Its assigned International Nonproprietary Name is Emideltide, but no Emideltide product has ever been approved or marketed, and there is no Emideltide-specific clinical literature. This site catalogs DSIP strictly as a research compound.
What is dsip peptide used for
In the research literature, DSIP has been studied for several distinct purposes, none of them an approved treatment. The largest body of human work targeted chronic insomnia: small 1980s trials gave 25 nmol/kg by vein and reported longer, less interrupted sleep, with effects that emerged in the second hour after injection [2]. A later double-blind study confirmed higher sleep efficiency and shorter sleep latency versus placebo but described the benefit as modest and concluded short-term treatment alone was unlikely to be of major therapeutic value [7]. Beyond sleep, researchers probed DSIP for effects on the stress (HPA) axis [4], on growth-hormone and pineal melatonin pathways [13], and, in rodents, on lifespan and tumor incidence [5]. A 2024 study engineered a blood-brain-barrier-crossing DSIP fusion peptide that outperformed the native molecule in a mouse insomnia model [6]. Importantly, DSIP has not been shown to treat insomnia or any sleep disorder in modern controlled trials, and it is not approved for any use.
What the strongest findings actually measured
The single most reproduced observation is the one DSIP is named for: enhancement of delta-band (deep-sleep) EEG activity after central administration, first shown in rabbits in 1977 [1] and later seen as delta-wave increases in the rat putamen [12]. The clearest human signal is the 1980s insomnia work, where intravenous DSIP at 25 nmol/kg improved disturbed sleep in middle-aged chronic insomniacs without daytime sedation [2]. The most striking long-term animal result comes from a DSIP-containing preparation (Deltaran) given to female mice, which increased maximum lifespan by 24.1% and reduced spontaneous tumor incidence 2.6-fold [5], though this line of work comes from a small set of related research groups and awaits independent replication. Read against those positives, the defining feature of the DSIP record is what is missing: no identified receptor, no large modern randomized trial, and effects that several human neuroendocrine studies failed to reproduce [3]. The detail and the gaps are logged in DSIP research.
How to read this log
Every quantitative claim here, a dose, a percentage, a duration, points to a numbered source on the references page, drawn from the peer-reviewed literature. The findings render as a logged set-table: each study is a row carrying its species, route, dose, and outcome, with a status tag marking whether the result has been replicated, comes from a single pilot, or is a review. Where the record has a hole, it is logged as a hole, not papered over. DSIP is an unusual compound to document precisely because its most famous effect is also its least settled: a 2006 review in the Journal of Neurochemistry called it a still unresolved riddle whose sleep evidence is extremely poorly documented and still weak [3]. That tension, real findings beside real gaps, is the whole point of reading DSIP by the numbers.