# What Is DSIP? The Delta Sleep-Inducing Peptide Explained

> What is DSIP? The delta sleep inducing peptide is a natural nine-amino-acid molecule (WAGGDASGE) named for enhancing deep-sleep delta brain waves — with no identified receptor, gene, or regulatory approval.

Nine amino acids, a famous EEG effect, an endogenous presence across the body — and no receptor anyone has found.

## In plain English

DSIP is short for delta sleep inducing peptide. A peptide is a small chain of amino acids — the building blocks of proteins — and this one is just nine links long (sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, or WAGGDASGE for short). It is something your body makes naturally; it has been found in blood, in the fluid around the brain and spinal cord, and even in milk. It got its name in 1977, when scientists infused it into rabbit brains and the slow "delta" waves of deep sleep grew stronger [1]. People interested in better sleep have taken an interest in it ever since. The strange part: despite decades of study, no one has found the receptor it acts on, the gene that makes it, or a clear mechanism. It is not an approved medicine anywhere. The rest of this page explains what it is, where it comes from, and what is genuinely known.

## What is dsip peptide

Answering "what is dsip peptide" precisely: DSIP is a linear nonapeptide (a nine-amino-acid chain), sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, molecular formula C35H48N10O15, molecular weight about 848.8 daltons, CAS number 62568-57-4. It was first isolated by Schoenenberger and Monnier from the cerebral venous blood of rabbits during electrically induced sleep, and characterized by its ability to enhance delta and spindle EEG activity [1]. A naturally phosphorylated form, DSIP-P, is also described and reported as more potent in some assays [11]. Its international nonproprietary name is Emideltide — but no Emideltide drug product has ever been approved or marketed, so the INN is essentially the only formal trace of it as a candidate medicine.

## What is dsip peptide used for

On "what is dsip peptide used for": in practice, the only context where DSIP is genuinely used is research, and the dominant interest is sleep — specifically the hope that it deepens slow-wave sleep, as its name and EEG signature suggest [1]. In the research literature it has been investigated far more broadly: small human pilot trials for chronic insomnia [2], pain, and alcohol and opiate withdrawal; animal work on the stress (HPA) axis [4], growth hormone, and neuroprotection; and aging studies using the Deltaran preparation [5]. It is important to be exact: none of these is an approved use. DSIP is not approved by the FDA or any other regulator for sleep or anything else, and it is sold only as a research chemical.

## Where DSIP comes from in the body

DSIP is endogenous — your body produces it — which sets it apart from purely synthetic research peptides. It has been detected in plasma, cerebrospinal fluid, and milk, usually bound to a carrier protein. It also turns up outside the brain: DSIP-like immunoreactivity has been mapped to gut endocrine cells across human, pig, and rat, with the human gut the richest known source, located in gastrin/CCK, secretin, and PYY/glicentin cells [13]. In dissociated mouse pituitary cells it was co-localized with TSH in thyrotrophs [12]. This wide distribution is part of the puzzle: a molecule found in so many tissues, with such a specific name, that still has no identified receptor or gene [3].

## Why DSIP is still a riddle

The defining feature of DSIP is how much remains unknown. After more than 40 years, no DSIP receptor, gene, or precursor protein has been conclusively identified, and a 2006 Journal of Neurochemistry review summarized the whole field as a "still unresolved riddle," judging the sleep evidence "extremely poorly documented and still weak" and observing that native DSIP's brain distribution lies in regions not clearly tied to sleep [3]. Its dose-response is parabolic — non-monotonic — so more is not reliably stronger [11]. Add the absence of a validated human pharmacokinetic profile and a plasma half-life of only minutes in animals, and DSIP emerges as a real, naturally occurring molecule with a famous name and a stubbornly incomplete biology. For the sleep angle specifically, see [DSIP for sleep](/for-sleep).

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A data-forward digest of the delta sleep-inducing peptide literature — every figure sourced, every gap named, and no clinic, vendor, or prescription behind the numbers.