DSIPWhat the studies show

Q: What kind of evidence exists for delta sleep-inducing peptide?

Small human studies. Small 1980s human sleep-laboratory studies from one group, a larger body of mixed animal work, and no identified gene, receptor or mechanism; there is no modern placebo-controlled trial.

A nine-amino-acid peptide pulled from sleeping rabbits in 1977 that, almost fifty years on, still has no known gene, receptor or mechanism.

5 min read · Small human studies · Updated November 2026

In short

Name: delta sleep-inducing peptide (sold by Progression Labs as DSIP)
Evidence: Small human studies
Bottom line: Small 1980s human sleep-laboratory studies from one group, a larger body of mixed animal work, and no identified gene, receptor or mechanism; there is no modern placebo-controlled trial.

Before you read this

This guide explains what published studies found. That is all it is.

It is not medical advice and it is not instructions for using anything. Where a dose appears, we are reporting what a named study gave the people or animals in it — a fact about the study, not an instruction to you.

The compounds here are not approved by the FDA for use in people and are sold for laboratory research only. A study tells you what happened to the subjects in it; it does not tell you what would happen to you. Talk to a doctor first.

What it is

Delta sleep-inducing peptide, usually shortened to DSIP, is a chain of nine amino acids (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu). It was isolated in 1977 by Schoenenberger and Monnier in Basel. They put rabbits to sleep by low-frequency electrical stimulation of the thalamus, collected blood draining from the sleeping animals' brains, infused it into awake rabbits, and found that the recipients showed more delta-wave (deep-sleep) activity on EEG. They then purified the active fraction down to this one peptide and named it for what it appeared to do ¹. The "delta" refers to the slow brain waves of deep sleep, not to anything about the molecule itself.

The studies below call this molecule delta sleep-inducing peptide. Progression Labs sells it as DSIP; the guide uses the store's name and the papers use theirs.

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The rabbit experiments

The 1977 paper reported that the purified peptide, infused into the brain ventricles of rabbits, raised delta-wave EEG activity and sleep time over the following hours compared with control infusions ¹. Through the 1980s many groups tried to repeat and extend this in rabbits, rats, cats and mice. A 1984 review by Graf and Kastin went through that work and found studies that saw more sleep, studies that saw none, and studies in which the peptide changed body temperature, blood pressure or stress-hormone levels instead; the sleep effect, where it appeared, was modest and depended on dose, timing and species ².

The human sleep studies

In the early 1980s Schneider-Helmert and colleagues, working with the peptide's discoverers, gave DSIP intravenously to small groups of healthy volunteers and people with chronic insomnia and recorded their sleep in a laboratory. They reported higher sleep efficiency and less time awake on some nights, with the clearest changes often appearing the night after the infusion rather than the night of it ³. A 1983 paper from the same group added daytime measures and argued that the peptide did more than induce sleep: some subjects reported feeling more alert and less stressed during the day, which the authors framed as a general normalising effect rather than a sedative one ⁴.

These studies were small, not always blinded, and came almost entirely from the group that found the peptide. Other laboratories had difficulty reproducing a reliable effect on sleep, and by the end of the 1980s the human work had largely stopped ⁵. There has been no modern randomised, placebo-controlled trial since.

Why the mechanism is still unknown

Nearly every peptide that acts in the body is cut from a larger precursor protein, and that precursor is encoded by a gene. No gene for DSIP has ever been found, in rabbits, rats or humans, and no receptor for it has been identified. A 2006 review in the Journal of Neurochemistry put the problem in its title: DSIP is "a still unresolved riddle" ⁵. Antibodies raised against the peptide do bind something in brain tissue and blood, which suggests a related molecule exists in the body, but what that molecule is, and whether the synthetic nine-amino-acid chain is the same thing, remains open ⁵.

The same review notes that the peptide is broken down within minutes in blood, which makes it hard to explain how a single infusion could change sleep hours later, and lists the other effects reported in animals over the years: shifts in body temperature, in stress-hormone release and in pain thresholds. That spread of effects, with no receptor to tie them together, is a large part of why no single mechanism has stuck ⁵.

People

The entire human record is the handful of 1980s sleep-laboratory studies described above, in small numbers of subjects. DSIP is not an approved medicine anywhere. The 2006 review also mentions Russian clinical work on a DSIP preparation in alcohol withdrawal; those studies were small and have not been repeated elsewhere ⁵. What a person can honestly be told is that the peptide was named for an effect seen in rabbits, that the effect was hard to reproduce, and that nobody has yet shown how it would work.

What these studies are, and aren't

Small human studies. Small 1980s human sleep-laboratory studies from one group, a larger body of mixed animal work, and no identified gene, receptor or mechanism; there is no modern placebo-controlled trial.