DSIP Results: What Studies Measured and When
What published studies measured for DSIP, when those outcomes were measured, and what is still unproven.
What studies measured
Each outcome below comes from a published study, with its type and size, strongest design first. Animal and cell results are labelled as such and are not human results.
| Outcome | Result | Study type | Source |
|---|---|---|---|
| Anaesthetic depth (BIS) | DSIP lightened anaesthetic depth (higher BIS, less delta rhythm) and raised heart rate; the opposite of the hypnotic effect predicted. | Human RCTn = 24 | European journal of anaesthesiology 2009, PMID 19142086 |
| Growth hormone and prolactin | DSIP did not change growth hormone or prolactin secretion. | Human controlled trialn = 8 | Psychoneuroendocrinology 1993, PMID 8475226 |
| Sleep efficiency and latency | Polysomnography showed higher sleep efficiency and shorter sleep latency with DSIP than placebo. | Human RCTn = 16 | Neuropsychobiology 1992, PMID 1299794 |
| Overall therapeutic benefit | The authors concluded short-term DSIP is unlikely to be of major therapeutic benefit in chronic insomnia; subjective sleep quality did not change. | Human RCTn = 16 | Neuropsychobiology 1992, PMID 1299794 |
| Sleep time and clinical significance | Sleep improved slightly under DSIP but the authors judged it of little clinical significance. | Human controlled trial | International journal of clinical pharmacology research 1987, PMID 3583493 |
| Night sleep | DSIP substantially improved night sleep with the first and with repeated doses. | Human controlled trialn = 14 | European neurology 1987, PMID 3622582 |
| Daytime alertness | Daytime alertness and performance increased significantly. | Human controlled trialn = 14 | European neurology 1987, PMID 3622582 |
| Sleep normalisation in insomniacs | Four consecutive injections normalised disturbed sleep in insomniacs in this early series. | Human controlled trial | Neuropsychobiology 1983, PMID 6689058 |
| Latency and duration | Sleep induction took about 1 hour to start and effects lasted up to 20 hours. | Human controlled trial | Neuropsychobiology 1983, PMID 6689058 |
| Total sleep time | Median total sleep time rose by 59% in the 130 minutes after a morning DSIP infusion versus placebo. | Human controlled trialn = 6 | International journal of clinical pharmacology, therapy, and toxicology 1981, PMID 6895513 |
| Plasma DSIP-like immunoreactivity | Endogenous DSIP-like immunoreactivity did not differ significantly between groups. | Human observationaln = 30 | Peptides 1995, PMID 8532601 |
| Sleep duration and quality | Longer, less interrupted sleep with no day-time sedation or other side effects in 6 insomniacs after a single dose. | Human uncontrolled trialn = 6 | Experientia 1981, PMID 7028502 |
| Sleep promotion by DSIP fusion peptide | A DSIP fusion peptide restored neurotransmitter imbalance better than DSIP alone and may enhance sleep in insomniac mice. | Animal · mouse (not a human result) | Frontiers in pharmacology 2024, PMID 39444618 |
| Seizures | DSIP and DSIP-12 reduced seizure incidence, grade and duration in rats and increased delta and theta EEG power. | Animal · rat (not a human result) | Seizure 2005, PMID 15911358 |
| CSF penetration | DSIP and analogs significantly crossed the blood-CSF barrier in dogs, depending on plasma level, half-life and lipophilicity. | Animal · dog (not a human result) | Brain research bulletin 1986, PMID 3768731 |
| Clearance and half-life | DSIP disappeared rapidly from dog plasma, with a mean half-life of 4.0 +/- 0.7 min. | Animal · dog, monkey and rat (not a human result) | Neuroendocrinology 1984, PMID 6379493 |
- All human DSIP trials found are from 1981-1992 (plus one 2009 anaesthesia study), small (6 to 16 participants per study), and used intravenous dosing of 25 nmol/kg. Results are mixed: some report improved sleep, but the largest double-blind insomnia study (n=16) concluded short-term DSIP is unlikely to be of major therapeutic benefit.
- No recent human trial of DSIP for sleep has been published in PubMed as of 2 October 2026. Evidence for sleep rests on these older small trials; no goal other than sleep has human support, and DSIP's natural role is described as still unresolved in the literature.
- Half-life is only available from animals (dog, monkey, rat; minutes); no human half-life was found. The human trials used intravenous injection, not the nasal or subcutaneous routes sold online.
- The 2009 randomized trial found DSIP lightened rather than deepened anaesthesia, the opposite of the hypothesis tested; it is included for completeness.
- DSIP is not FDA-approved.
Typical timeline
When the studies above measured their outcomes. This is the study schedule, not a promise of when anyone will notice a change.
| When | What was measured | Study type | Source |
|---|---|---|---|
| second hour after injection | sleep-promoting effect onset | Human uncontrolled trialn = 6 | Experientia 1981, PMID 7028502 |
Before-and-after photos
We don't publish before-and-after photos. They can't be verified, rarely show dose, diet or other drugs, and only the most dramatic results get posted.
Common questions
How long does DSIP take to work?
The studies we summarise measured outcomes at set points, for example sleep-promoting effect onset at second hour after injection. Timelines outside studies vary.
Do you show DSIP before and after photos?
No. Photos can't be verified, rarely show dose, diet or other drugs, and only the most dramatic ones get posted. We summarize measured outcomes instead.
More on DSIP
Sources
- 1Delta sleep-inducing peptide alters bispectral index, the electroencephalogram and heart rate variability when used as an adjunct to isoflurane anaesthesia.European journal of anaesthesiology · 2009PMID 19142086Accessed 2 Oct 2026
- 2Delta sleep-inducing peptide administration does not influence growth hormone and prolactin secretion in normal women.Psychoneuroendocrinology · 1993PMID 8475226Accessed 2 Oct 2026
- 3Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study.Neuropsychobiology · 1992PMID 1299794Accessed 2 Oct 2026
- 4Study of delta sleep-inducing peptide efficacy in improving sleep on short-term administration to chronic insomniacs.International journal of clinical pharmacology research · 1987PMID 3583493Accessed 2 Oct 2026
- 5Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia.European neurology · 1987PMID 3622582Accessed 2 Oct 2026
- 6Effects of DSIP in man. Multifunctional psychophysiological properties besides induction of natural sleep.Neuropsychobiology · 1983PMID 6689058Accessed 2 Oct 2026
- 7Acute and delayed effects of DSIP (delta sleep-inducing peptide) on human sleep behavior.International journal of clinical pharmacology, therapy, and toxicology · 1981PMID 6895513Accessed 2 Oct 2026
- 8Delta sleep-inducing peptide in normal humans and in patients with sleep apnea and narcolepsy.Peptides · 1995PMID 8532601Accessed 2 Oct 2026
- 9The influence of synthetic DSIP (delta-sleep-inducing-peptide) on disturbed human sleep.Experientia · 1981PMID 7028502Accessed 2 Oct 2026
- 10Pichia pastoris secreted peptides crossing the blood-brain barrier and DSIP fusion peptide efficacy in PCPA-induced insomnia mouse models.Frontiers in pharmacology · 2024PMID 39444618Accessed 2 Oct 2026
- 11Antiepileptic activity of delta sleep-inducing peptide and its analogue in metaphit-provoked seizures in rats.Seizure · 2005PMID 15911358Accessed 2 Oct 2026
- 12Entry of DSIP peptides into dog CSF: role of physicochemical and pharmacokinetic parameters.Brain research bulletin · 1986PMID 3768731Accessed 2 Oct 2026
- 13Development of an enzyme immunoassay for delta sleep-inducing peptide (DSIP) and its use in the determination of the metabolic clearance rate of DSIP administered to dogs.Neuroendocrinology · 1984PMID 6379493Accessed 2 Oct 2026
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