Peptide Evidence Index

DSIP

Evidence last reviewed: September 2026

Quick answers

What is it?: DSIP (Delta Sleep-Inducing Peptide) is a synthetic chain of nine amino acids, first identified in the 1970s in the blood of rabbits during electrically induced sleep.
Why are people interested in it?: It's marketed as a sleep aid, and it actually has more human trial history than most peptides sold online — but that history is old and the results disagree with each other.
What has actually been studied?: Double-blind, placebo-controlled human trials tested it for chronic insomnia; separate studies looked at opioid withdrawal, use as a general-anaesthesia adjunct, and effects on stress-hormone secretion.
How strong is the evidence?: Mixed human evidence — a cluster of small, decades-old double-blind trials exist, but the more methodologically careful ones found effects too small to matter clinically.
What don't we know yet?: Whether DSIP does anything for sleep beyond a small, possibly not clinically meaningful effect, whether early positive reports would replicate under modern standards, and what long-term use does.
Where can I read the original research?: See the registry and study records below — five published studies from 1981 to 2009, with zero trials ever registered on ClinicalTrials.gov.

Plain-English overview

DSIP (Delta Sleep-Inducing Peptide) is a synthetic chain of nine amino acids, first identified in the 1970s in the blood of rabbits during electrically induced sleep, which is where its name comes from. It has never been approved as a medicine anywhere and has no accepted supplement use. DSIP has a real, if old, cluster of double-blind, placebo-controlled human trials — more direct human testing than several other peptides in this library — but the studies disagree with each other about whether it actually helps sleep. Zero trials are registered on ClinicalTrials.gov, and nothing has been published on DSIP in humans since 2009. All human evidence traces to roughly a dozen small studies published between 1981 and 2009, mostly from two research groups: the Swiss group that helped discover the peptide, and a Netherlands-based group that ran the largest and most skeptical of the sleep trials.

What researchers are studying it for

sleep / chronic insomnia
opioid withdrawal
general anaesthesia adjunct
HPA-axis and hormone secretion

Current evidence level

Mixed human evidence

Regulatory status: Not an approved medicine. Evidence strength and approval are scored separately; approval is a regulatory decision about a specific use, not a measure of how much research exists.

Human research

DSIP's human evidence centers on a handful of double-blind, placebo-controlled trials for chronic insomnia, most using the same intravenous dose of 25 nanomoles per kilogram of body weight. The earliest report (Schneider-Helmert & Schoenenberger, Lancet 1981) was a double-blind, randomized study describing improved sleep in insomniacs and was one of the first positive results. A follow-up study by Schneider-Helmert (1987, n=14) also reported improved night sleep and daytime alertness under double-blind, placebo-controlled conditions. But a separate double-blind, placebo-controlled crossover trial by Monti et al. (1987) concluded that "sleep improvement under DSIP treatment is of little clinical significance." The largest and most recent sleep trial, Bes et al. (1992, n=16), found statistically significant effects that were weak and possibly explained by chance changes in the placebo group, with the authors concluding that short-term DSIP treatment "is not likely to be of major therapeutic benefit." Outside of sleep, DSIP has been tested for other uses in small, separate studies: it suppressed the stress hormone marker ACTH in some experiments but had no measured effect on cortisol, growth hormone, prolactin, or vasopressin secretion; one open-label (unblinded) trial tested it as an aid for opioid withdrawal; and in the most recent human study located (Pomfrett et al., 2009, n=24, randomized), DSIP was tested as an adjunct to general surgical anaesthesia, where it paradoxically lightened anaesthetic depth rather than deepening it, as measured by bispectral index, EEG, and heart-rate variability. Zero trials of DSIP are registered on ClinicalTrials.gov. Individual study sizes across this body of work ranged from about 6 to 24 people, and no trial has been run in the modern era or tested repeated dosing beyond about a week.

Animal and preclinical research

DSIP was originally isolated from the blood of rabbits during electrically induced sleep in the 1970s, which is how it was discovered and named, but no animal efficacy or mechanism studies are described in the published research reviewed for this profile.

Major findings

The earliest double-blind, randomized report (Schneider-Helmert & Schoenenberger, Lancet 1981) and a 1987 follow-up (Schneider-Helmert) described improved night sleep and daytime alertness in chronic insomniacs.
A separate 1987 double-blind, placebo-controlled crossover trial (Monti et al.) concluded sleep improvement under DSIP was "of little clinical significance."
The largest sleep trial (Bes et al., 1992, n=16) found weak, possibly chance-driven effects and concluded DSIP "is not likely to be of major therapeutic benefit."
DSIP suppressed the stress hormone marker ACTH in some experiments but had no measured effect on cortisol, growth hormone, prolactin, or vasopressin.
A 2009 randomized study (Pomfrett et al., n=24) testing DSIP as an anaesthesia adjunct found it paradoxically lightened anaesthetic depth rather than deepening it.
All the double-blind sleep trials used the same intravenous dose (25 nanomoles per kilogram), yet disagreed on whether that dose produced a clinically meaningful effect.
Zero trials of DSIP are registered on ClinicalTrials.gov, and nothing has been published on it in humans since 2009.

What has not been established

Whether DSIP does anything for sleep beyond a small, and possibly not clinically meaningful, effect.
Whether the early positive reports would replicate under modern trial standards.
What repeated or long-term use does — no study ran longer than about a week of dosing.
What an unregulated vial sold online today actually contains.
Whether cumulative benefit or harm occurs with repeated dosing beyond about a week — no trial has tested this.

Important limitations

All human trials are decades old; nothing has been published in humans since 2009.
Zero trials are registered on ClinicalTrials.gov.
The most methodologically careful trials found effects too small to be clinically meaningful.
Study sizes were small, ranging from about 6 to 24 people.
The earliest, most positive reports came from the same research group that discovered DSIP, while the larger, more skeptical trials came from an independent group.

Regulatory status

DSIP has never been approved as a medicine in the United States, the EU, or the UK, or in any other major jurisdiction identified in this review. It has no accepted clinical or supplement use anywhere.

Primary research sources

Schneider-Helmert & Schoenenberger, "Synthetic delta-sleep-inducing peptide improves sleep in insomniacs": The Lancet, 1981; DOI: 10.1016/s0140-6736(81)92417-x
Schneider-Helmert, "Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia": 1987; DOI: 10.1159/000116143
Monti et al., "Study of delta sleep-inducing peptide efficacy in improving sleep on short-term administration to chronic insomniacs": International Journal of Clinical Pharmacology Research, 1987; PMID: 3583493
Bes et al., "Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study.": 1992; DOI: 10.1159/000118919
Pomfrett et al., "Delta sleep-inducing peptide alters bispectral index, the electroencephalogram and heart rate variability when used as an adjunct to isoflurane anaesthesia": European Journal of Anaesthesiology, 2009; DOI: 10.1097/EJA.0b013e32831c8644

Full evidence entry (complete data, registry records, dosing evidence)

Mixed human evidence

Controlled human trials exist and disagree

At a glance

Also known as: Delta Sleep-Inducing Peptide
Class: Synthetic nonapeptide
Derived from: First identified in the blood of rabbits during electrically induced sleep in the 1970s; later synthesized as a nine-amino-acid peptide
Registered human trials: 0
…with published results: 0
Largest human trial: None registered on ClinicalTrials.gov. The largest published double-blind study is 16 chronic insomniacs (Bes et al., 1992).
Studied for: sleep / chronic insomnia, opioid withdrawal, general anaesthesia adjunct, HPA-axis and hormone secretion
Dosing evidence: No human dose establishedNo controlled human trial has established DSIP as effective at any dose; the studies that exist tested a single repeated intravenous amount without agreeing on whether it worked.
Regulatory status: Not approved as a medicine in the United States, the EU, or the UK. Not an approved drug in any major jurisdiction.

What it is

DSIP is a synthetic chain of nine amino acids. It was first identified in the 1970s in the blood of rabbits during electrically induced sleep, which is where the name comes from. It is not a hormone or a supplement with any approved medical use — it has never been approved as a medicine anywhere.

What the studies actually found

DSIP has a real, if old, cluster of double-blind, placebo-controlled human trials — more direct human testing than several other peptides in this library. But the results don't agree with each other.

The earliest reports, published in the early-to-mid 1980s by the peptide's discoverers, described DSIP improving night sleep and daytime alertness in small groups of chronic insomniacs. Later, more methodologically careful double-blind trials found much less. A 1987 study concluded any sleep improvement was "of little clinical significance." A 1992 study — the largest of the group, at 16 patients — found the statistically significant effects were weak and possibly explained by chance changes in the placebo group, and its own authors concluded that short-term DSIP treatment "is not likely to be of major therapeutic benefit."

DSIP has also been tested for things unrelated to sleep. In small, separate studies it suppressed a stress hormone marker (ACTH) in some experiments but had no effect on cortisol, growth hormone, prolactin, or vasopressin secretion. One open-label (unblinded) trial tested it as an aid for opioid withdrawal. And in 2009 — the most recent human study found — it was tested as an adjunct to general surgical anaesthesia. There it did the opposite of what its name promises: instead of deepening anaesthesia, it paradoxically lightened it.

What exists in humans

Zero trials are registered on ClinicalTrials.gov. All human data traces to roughly a dozen small studies published between 1981 and 2009, mostly from two research groups — the Swiss group that helped discover the peptide, and a separate Netherlands-based group that ran the largest and most skeptical of the sleep trials. Individual study sizes ranged from about 6 to 24 people. Nothing has been published on DSIP in humans since 2009.

What doses have been studied in humans

The double-blind trials that exist almost all used the same intravenous dose — 25 nanomoles per kilogram of body weight, given by injection or slow infusion, as a single dose or repeated over several nights. That amount was consistent across the sleep trials (Bes et al., Monti et al., Schneider-Helmert et al.) and the separate neuroendocrine studies that measured hormone secretion.

What that consistency does not give you is a dose that works. The trials that used it disagree on whether it did anything meaningful for sleep — the two most methodologically careful studies found the effect too small to matter clinically. No trial has been run in the modern era, none tested repeated dosing beyond about a week, and none was designed to compare doses against each other to find an optimal or minimum effective amount.

All of this dosing evidence comes from intravenous administration under laboratory (polysomnography) conditions. None of it applies to the injectable or oral products sold online today, which are used outside any clinical or laboratory setting and at doses no trial has tested.

What remains unknown

Whether DSIP does anything for sleep beyond a small, and possibly not clinically meaningful, effect
Whether the early positive reports would replicate under modern trial standards
What repeated or long-term use does — no study ran longer than about a week of dosing
What an unregulated vial sold online today actually contains

Registry and study records

Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study.: PubMed · Bes et al., 1992. n=16, double-blind, placebo-controlled. Authors concluded short-term DSIP treatment 'is not likely to be of major therapeutic benefit.' DOI: 10.1159/000118919
Study of delta sleep-inducing peptide efficacy in improving sleep on short-term administration to chronic insomniacs: PubMed · Monti et al., 1987. Double-blind, placebo-controlled crossover. Concluded 'sleep improvement under DSIP treatment is of little clinical significance.'
Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia: PubMed · Schneider-Helmert, 1987. n=14, double-blind, placebo-controlled. Reported improved night sleep and daytime alertness. DOI: 10.1159/000116143
Synthetic delta-sleep-inducing peptide improves sleep in insomniacs: PubMed · Schneider-Helmert & Schoenenberger, Lancet 1981. Double-blind, randomized. One of the earliest positive reports. DOI: 10.1016/s0140-6736(81)92417-x
Delta sleep-inducing peptide alters bispectral index, the electroencephalogram and heart rate variability when used as an adjunct to isoflurane anaesthesia: PubMed · Pomfrett et al., 2009. n=24, randomized. Tested as a general-anaesthesia adjunct rather than a sleep aid; DSIP paradoxically lightened anaesthetic depth. DOI: 10.1097/EJA.0b013e32831c8644

See the full Evidence Index →

Evidence last reviewed: September 2026. Peptide Proof reports what studies found. We do not give medical advice, dosing guidance, or treatment recommendations.