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What it is
Delta sleep-inducing peptide, usually shortened to DSIP, is a short peptide first isolated during experiments on sleep in rabbits. Its name reflects those early observations, but the name is more confident than the evidence. Researchers have not established DSIP as a normal circulating sleep hormone with one clear receptor or one predictable effect.
Human research exists, which puts DSIP ahead of many compounds sold as research peptides. The problem is that the trials were tiny, used intravenous infusions, and produced inconsistent sleep findings. DSIP is not FDA approved, and modern research-vial products are not equivalent to a regulated medicine.
What people research it for
Possible improvement in sleep efficiency
Early human dataA double-blind study in 16 people with chronic insomnia found higher sleep efficiency and shorter sleep latency than placebo, but the authors judged the effects weak and unlikely to provide major therapeutic benefit.
Possible effects on sleep timing and stage 2 sleep
Early human dataSmall controlled studies reported shorter sleep onset or more stage 2 sleep. The findings were not consistent across outcomes, and baseline differences complicated interpretation.
Stress-axis signaling
Early human dataA randomized crossover study in 11 healthy men found reduced ACTH-like immunoreactivity after intravenous DSIP, suggesting an effect on stress-axis signaling. It did not establish a clinical benefit.
Sleep without classic sedation
Early human dataAn early six-person experiment reported more sleep after DSIP without the behavioral pattern of a conventional sedative. The sample was too small to establish efficacy or safety.
How it works
DSIP does not have a well-established receptor-level mechanism. Older experiments suggest it may influence sleep regulation, stress signaling, and the hypothalamic-pituitary-adrenal axis rather than acting like a conventional sedative that simply suppresses brain activity.
That distinction fits the early human findings. Some studies reported changes in sleep onset, sleep efficiency, or stage 2 sleep without classic daytime sedation. Another randomized study found lower ACTH-like immunoreactivity after an intravenous exposure, but cortisol did not show the same clear change. These observations are clues, not a settled explanation.
What the research actually shows
The earliest controlled human experiment included six healthy volunteers in a double-blind crossover design. Investigators infused DSIP intravenously in the morning and reported a 59 percent median increase in sleep during a 130-minute observation period compared with placebo. They also reported shorter sleep onset and better sleep efficiency that night, but six participants is far too small for a dependable treatment conclusion.
A separate 1981 study tested intravenous DSIP in six middle-aged people with chronic insomnia. It reported longer sleep, fewer interruptions, and slightly more REM sleep, with no daytime sedation. The apparent sleep-promoting effect emerged mainly in the second hour after exposure, while the first hour showed a slight arousing signal. This small study was encouraging but not independently decisive.
Later controlled work was less persuasive. In a four-night double-blind crossover study of people with insomnia, DSIP increased total sleep and stage 2 sleep, but several differences were already present at baseline. Slow-wave sleep and REM sleep were unchanged. The authors concluded that the improvement had little clinical significance.
The largest clearly described trial in this group enrolled 16 chronic insomnia patients for five laboratory nights. DSIP improved sleep efficiency and sleep latency versus placebo, yet subjective sleep quality and most other measures did not improve. The authors wrote that the statistically significant effects were weak and partly may have reflected an incidental change in the placebo group.
DSIP has also been studied outside sleep scoring. Eleven healthy men ages 25 to 39 received DSIP or saline in a randomized double-blind crossover experiment. ACTH-like immunoreactivity fell after DSIP, while the study did not establish that this laboratory change improved sleep, stress, or health. A later review called DSIP a still unresolved riddle, which remains a fair summary of the evidence.
Handling & storage
Storage at a glance
Published stability data- Lyophilized
- below -18°C for long-term storage
- about 3 weeks at room temperature according to the manufacturer technical sheet
- Store dry and tightly sealed.
- Reconstituted
- 4°C
- Use within 2-7 days
- Technical product guidance. Longer retail claims were not treated as equivalent evidence.
- Light
- Protect from light and moisture.
- Room temperature
- Dry lyophilized DSIP is listed as stable for about 3 weeks at room temperature.
- Reconstitution
- manufacturer-specified sterile diluent
- For longer laboratory storage, freeze single-use aliquots and avoid repeated freeze-thaw cycles.
Basis: Published stability data. Sources: ProSpec DSIP technical product page, GenScript general peptide storage
The available technical product sheet describes dry DSIP as a lyophilized research material. It calls for storage below -18°C for long-term use, protected from light and moisture, while noting that dry material can remain stable for about three weeks at room temperature.
After reconstitution, the same technical guidance gives a short 2 to 7 day window at 4°C. Longer refrigerated periods repeated by retail sellers were not treated as equivalent evidence. General peptide guidance supports keeping solutions cold, using single-use aliquots for longer laboratory storage, and avoiding repeated freeze-thaw cycles.
Safety & cautions
The small early trials described DSIP as generally well tolerated and did not identify classic next-day sedation. Those studies involved only a few dozen people in total, brief observation periods, and intravenous research exposures. They cannot establish uncommon adverse effects, interactions, or long-term safety.
DSIP has no FDA-approved medical use and no modern prescribing label. Research vials may vary in identity, purity, fill amount, sterility, and endotoxin burden. Pregnancy, childhood, older age, major illness, and use with sedatives have not been adequately studied.
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Frequently asked questions
Is DSIP FDA approved?
No. DSIP is not FDA approved as a medicine for insomnia or any other condition.
Does DSIP reliably increase deep sleep?
The human evidence does not show a reliable increase in deep slow-wave sleep. One controlled insomnia study found more stage 2 sleep but no change in stages 3 and 4 or REM sleep.
How strong is the human evidence?
Early human research exists, but the studies were small, old, and inconsistent. The best-described 16-person trial found weak objective changes and no improvement in subjective sleep quality.
Is DSIP a sedative?
Early investigators reported sleep-related changes without the usual behavioral signs of a conventional sedative. That does not prove DSIP is effective or safe.
Why is DSIP called an unresolved peptide?
Researchers have not established one clear receptor, a consistent effect across studies, or a convincing modern clinical use. A scientific review described it as a still unresolved riddle.
How should laboratory DSIP be stored?
The checked technical sheet calls for dry long-term storage below -18°C, protection from light and moisture, and only 2 to 7 days at 4°C after reconstitution.
Sources
- Bes et al., double-blind study in 16 chronic insomnia patients
- Schneider-Helmert et al., acute and delayed effects in six volunteers
- Schneider-Helmert and Schoenenberger, disturbed sleep study
- Monti et al., short-term study in chronic insomnia
- Graf et al., ACTH study in 11 healthy men
- Delta sleep-inducing peptide, a still unresolved riddle
- ProSpec DSIP technical product page
- GenScript peptide storage and handling guidance
Last reviewed September 17, 2026. This guide is educational and research-focused, not medical advice. DSIP products referenced on PeptidePub are sold by third parties as materials for laboratory research use only, not for human or animal consumption.
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