# DSIP Peptide: An Independent Map of the Delta Sleep-Inducing Peptide Research Literature > DSIP peptide — nine amino acids, isolated in 1974 — has been studied across more than two dozen human and animal trials for sleep, stress, and neuroprotection. Independent research digest. ## What DSIP peptide has been documented to do DSIP peptide has produced statistically significant improvements in sleep efficiency in double-blind, placebo-controlled human trials [1][3][4]. In the best-powered study (n=16 chronic insomniacs, Bes 1992), DSIP administered intravenously at 25 nmol/kg improved sleep efficiency and shortened sleep latency vs. placebo across three consecutive treatment nights [1]. A seven-night protocol (Schneider-Helmert 1987) found benefits beginning at the first dose and maintained after treatment ended [3]. A ten-injection course normalized sleep in six of seven severe insomniacs, with effects measured at three-to-seven-month follow-up [4]. Beyond sleep, the record covers growth hormone secretion [6][7], pineal indolamine release [19], LH modulation [20], pain reduction [18], opioid and alcohol withdrawal [15][16], and a narcolepsy case study showing reduced daytime sleep attacks and enhanced nighttime REM [17]. ## What Is Delta Sleep-Inducing Peptide? Delta sleep-inducing peptide (also called DSIP or emideltide) is a naturally occurring nonapeptide of nine amino acids: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. Molecular weight: 849 Da. It was isolated by Monnier and Schoenenberger from the cerebral venous blood of sleeping rabbits between 1963 and 1977, with chemical synthesis completed in 1977. An endogenous phosphorylated form, DSIP-P, is found in human plasma and is reported to be more potent and degradation-resistant than the unphosphorylated nonapeptide [23]. DSIP crosses the blood-brain barrier via a high-affinity saturable transport mechanism — confirmed in perfused guinea pig brain using radiolabeled tracer and competitive inhibition by L-tryptophan, the N-terminal residue [10]. Plasma half-life is 2-4 minutes in rat, monkey, and dog models [11], yet in-vivo effects persist hours to days. Carrier protein binding and downstream neuroendocrine cascade initiation are the proposed explanations. Endogenous DSIP levels show a distinct circadian pattern in humans: plasma concentrations peak at approximately 15:00 and reach a nadir at approximately 01:00, with levels falling during REM and slow-wave sleep — a circadian coupling to body temperature (r²=0.66, p<0.0001) rather than direct sleep onset [21]. DSIP (emideltide) is not approved by the FDA or EMA for any human therapeutic indication. It is under evaluation by the FDA Pharmacy Compounding Advisory Committee for possible inclusion on the 503A Bulk Drug Substances List (docket FDA-2025-N-6895, scheduled July 2026). ## Does DSIP help you sleep? Four controlled human studies address this question directly. Bes et al. (1992) found higher sleep efficiency and shorter sleep latency vs. placebo in 16 chronic insomniacs given DSIP at 25 nmol/kg IV across three consecutive nights [1]. Schneider-Helmert and Schoenenberger (1981) reported longer sleep duration, fewer nocturnal interruptions, a modest increase in REM sleep, and no daytime sedation in six middle-aged insomniacs given an acute IV dose [2]. Schneider-Helmert (1987) extended this to a seven-night protocol in 14 patients and found significant improvements in both sleep and daytime alertness that persisted after the treatment course ended [3]. Kaeser (1984) reported sleep normalization in six of seven severe insomniacs given a ten-injection course, with effects maintained at three-to-seven-month follow-up [4]. Effect sizes across these studies are modest; the Bes study concludes that short-term treatment alone is unlikely to provide major therapeutic benefit. No large Phase III trial has been completed. ## Is DSIP a sleeping pill? No. DSIP is a naturally occurring neuropeptide, not a sedative or hypnotic agent. It does not act on GABA-A receptors — the mechanism of action for benzodiazepines and Z-drugs. It appears to modulate sleep architecture: promoting slow-wave (delta) sleep while leaving REM sleep intact or slightly increased [2][13]. ## The open questions: receptor, gene, and mechanism A 2006 review by Kovalzon and Strekalova concluded that, despite four decades of research, neither a dedicated DSIP receptor nor a precursor gene encoding the nonapeptide has ever been isolated [24]. The authors proposed that a DSIP-like endogenous peptide — not DSIP itself — may underlie the full biological activity observed, and that DSIP's mechanistic link to sleep remains unresolved. --- Nine residues, twenty-five studies, one grid — the DSIP peptide research record indexed by finding, not by vendor.