Two selected small studies examined delta sleep-inducing peptide (DSIP) in chronic insomnia. Their short observation periods and incompletely described formulations limit transfer to other preparations or uses.12
Bottom line from this bounded source set
The two reports differ: one described improved sleep and daytime measures, while the other found weak objective changes and no improvement in subjective sleep quality. These small studies do not establish durable benefit or adequately characterize harms.12
Reviewed study record
Chronic insomnia: matched-pairs study
Design
A blinded placebo-controlled parallel-group study used matched pairs and five consecutive laboratory nights.1
Population
Sixteen patients with chronic insomnia participated.1
Outcomes reported
Sleep efficiency and sleep latency differed from placebo, but the authors described the effects as weak and partly attributable to changes in the placebo group. Subjective sleep quality did not improve.1
Limitations
The abstract does not describe random allocation or detailed adverse events. A short, small study cannot establish sustained benefit or uncommon harms.1
Reviewed study record
Chronic insomnia: sleep and daytime performance
Design
A blinded placebo-controlled study observed sleep and daytime performance over seven successive treatment nights.2
Population
Fourteen middle-aged participants with chronic insomnia were studied.2
Outcomes reported
The authors reported improved sleep, alertness and daytime performance, with sleep effects maintained on the first post-treatment night.2
Limitations
The abstract does not clearly describe allocation, the full comparator sequence or adverse events. The findings do not establish longer-term efficacy or safety.2
No registered Crossref update in the reviewed snapshotChecked September 15, 2026 for DOI 10.1159/000118919. This bounded result is not proof that the publication has never been corrected or retracted. Open the pinned Crossref work endpoint ↗
No registered Crossref update in the reviewed snapshotChecked September 15, 2026 for DOI 10.1159/000116143. This bounded result is not proof that the publication has never been corrected or retracted. Open the pinned Crossref work endpoint ↗