Delta Sleep-Inducing Peptide (DSIP) is a nonapeptide (9 amino acids) with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), first isolated in 1977 by Marcel Monnier and colleagues at the University of Basel, Switzerland. The discovery arose from a remarkable experiment: when cerebral venous blood from electrically sleep-induced rabbits was transfused into awake rabbits, the recipients showed EEG changes consistent with delta-wave sleep induction. DSIP was purified from these dialysates as the active factor.
DSIP occupies a uniquely paradoxical position in peptide science. It is one of the most studied sleep-related peptides, yet after nearly 50 years of research, fundamental questions remain unanswered: no precursor gene or protein has been identified, no specific receptor has been found, and the exact mechanism by which it promotes sleep remains unknown. It has a very short half-life (~15 minutes in free form) due to rapid aminopeptidase degradation, yet it has been found in both free and carrier-bound forms across the hypothalamus, limbic system, pituitary, gut, pancreas, and in body fluids including breast milk.
DSIP has been described as a "sleep-promoting substance rather than a sedative." It appears to modulate sleep-wake patterns with greater effect when sleep is disturbed than in healthy subjects. A dose given during the day can improve sleep quality that night and for several nights afterward, which is pharmacologically unusual for a peptide with a 15-minute half-life. This suggests DSIP may trigger downstream cascading effects rather than directly inducing sleep.
Evidence context: The clinical evidence for DSIP is genuinely conflicting. Some studies show benefits in chronic insomnia, others show minimal effects. One double-blind placebo-controlled trial in 16 chronic insomnia patients found modestly improved sleep efficiency and latency, but the authors concluded that short-term DSIP treatment "is not likely to be of major therapeutic benefit." Synthetic analogs with greater stability have shown stronger effects in some studies. The basic science is intriguing; the clinical translation is unresolved.
| Weeks | Dosage | Syringe units (U-100) |
|---|---|---|
| Week 1 | 0.1 mg | 6 units0.06 mL |
| Week 2 | 0.15 mg | 9 units0.09 mL |
| Week 3 | 0.2 mg | 12 units0.12 mL |
| Weeks 4–8 | 0.25–0.3 mg | 15–18 units0.15 mL – 0.18 mL |
| Weeks | Dosage | Syringe units (U-100) |
|---|---|---|
| Week 1 | 0.1 mg | 2 units0.02 mL |
| Week 2 | 0.15 mg | 3 units0.03 mL |
| Week 3 | 0.2 mg | 4 units0.04 mL |
| Weeks 4–8 | 0.25–0.3 mg | 5–6 units0.05 mL – 0.06 mL |
FrequencyOnce daily, subcutaneous, in the evening before sleep.
For review — not established human dosing. No modern trial establishes an amount, a schedule or a frequency for DSIP; the rows in the chart follow a circulated research protocol rather than the clinical reports cited on this page. The concentration strip above the chart is calculated from the vial and water volume and is correct.
Unverified — no cited human study establishes a daily subcutaneous frequency for DSIP.
The human reports behind DSIP date from the 1970s and 1980s, used inconsistent routes and preparations, and were never followed by dose-ranging work, so the week-by-week amounts charted here are a circulated protocol and are flagged for review rather than presented as established dosing. The evening timing is part of that protocol and reflects what the peptide was named for — delta sleep-inducing peptide — not a schedule any trial tested. A 5 mg vial made up with 3 mL is about 1.67 mg/mL and a 15 mg vial with 3 mL is 5 mg/mL, so the final 0.25 to 0.3 mg step is 15 to 18 units from the smaller vial and 5 to 6 units from the larger; every amount on either chart fits inside one 50-unit syringe, and the draws from the 15 mg vial are small enough that a unit or two of measurement error is a large proportional change. The final row is shown as the range the protocol gives rather than collapsed to a single figure, because narrowing it would be a claim the source does not make.
What this evidence establishes. No reliable human dosing exists for DSIP. The small clinical reports that exist date from the 1970s and 1980s, used inconsistent routes and preparations, and were not followed by dose-ranging work. There is no established dose, no established frequency, and no modern trial to anchor either. The table below is reconstitution arithmetic only — it converts a volume to a quantity and implies nothing about how much of it should be used.
For educational and laboratory research purposes only. It does not provide medical advice, dosing recommendations, or instructions for human or veterinary use. Syringe units assume a U-100 syringe, on which 1 mL is 100 units and a 50-unit syringe holds 0.5 mL.
DSIP's mechanism remains incompletely understood. Unlike most peptides profiled on this site, no specific receptor has been identified. Current evidence suggests it modulates multiple systems simultaneously:
Increases slow-wave (delta) sleep on EEG in rabbits, rats, mice, cats, and humans. Effects on REM sleep vary by species. Promotes sleep depth rather than acting as a sedative.
May affect GABA-A receptors, the same inhibitory pathways targeted by benzodiazepines and other sleep medications. Action may be via NMDA receptor interaction in the brain.
Regulates cortisol and ACTH secretion, potentially normalizing the stress axis. May reduce elevated cortisol levels, addressing a root cause of stress-related insomnia.
Plasma DSIP levels exhibit marked diurnal variation: low in mornings, higher in afternoons. Constant light exposure abolishes this rhythm. Correlation with circadian regulation established.
Homologous to glucocorticoid-induced leucine zipper (GILZ). May interact with components of the MAPK cascade, inhibiting Raf-1 activation and ERK phosphorylation.
Beyond sleep: analgesic activity, anticonvulsant effects in epilepsy models, anticarcinogenic properties (2.6-fold tumor reduction in lifetime mouse study), and geroprotective effects (24% maximum lifespan increase in mice).
The central mystery: After nearly 50 years of research, no gene encoding a DSIP precursor protein has been found, and no specific DSIP receptor has been identified. It is hypothesized that DSIP may complex with carrier proteins in vivo to prevent degradation, or exist as a component of a larger precursor molecule. Its regulation appears linked to glucocorticoids. This fundamental gap in understanding is unusual for a peptide this well-studied and raises questions about whether "DSIP" as measured in immunoassays always represents the same molecular entity.
DSIP has limited human safety data from small clinical studies conducted primarily in the 1980s-1990s:
| Concern | Risk Level | Rationale |
|---|---|---|
| Human clinical evidence | CONFLICTING | Some studies show sleep benefits, others show minimal effects. One controlled insomnia trial found modest improvements. Evidence base is small and contradictory. |
| No identified receptor | FUNDAMENTAL GAP | No specific DSIP receptor has been identified in nearly 50 years. This means the molecular target of exogenous DSIP administration is unknown. |
| Very short half-life | PHARMACOKINETIC | ~15 minutes in free form due to aminopeptidase degradation. May complex with carrier proteins in vivo. Raises questions about effective dosing and duration. |
| Pregnancy / breastfeeding | UNKNOWN | DSIP-like material found in breast milk. Effects on fetal/neonatal development are unstudied. Standard precaution for unstudied compounds. |
| Depression / psychiatric conditions | COMPLEX | Plasma and CSF DSIP levels deviate from normal in major depressive disorder, though studies conflict on direction (higher vs. lower). Caution warranted in psychiatric contexts. |
| HPA axis disorders | MODERATE | DSIP modulates cortisol and ACTH. Effects in patients with adrenal disorders, Cushing's syndrome, or Addison's disease are unknown. |
| Drug interactions | UNKNOWN | No drug interaction studies. DSIP may affect neurotransmitter levels and modulate sleep medication pathways (GABAergic, serotonergic). Concurrent use with sedatives, benzodiazepines, or antidepressants is unstudied. |
| Acute tolerability (clinical studies) | FAVORABLE | Human studies from the 1980s-90s report good acute tolerability. No serious adverse events attributed to DSIP in published clinical trials. |
| Long-term safety | UNKNOWN | No long-term human safety studies. The geroprotective mouse data is intriguing but unreplicated. |
FDA: DSIP is not FDA-approved for any indication. It has not entered formal clinical development in the United States. No IND application is known to have been filed.
Availability: DSIP is available from peptide suppliers and is used in integrative medicine and biohacking contexts for sleep optimization.
Key distinction: DSIP is a scientifically fascinating but clinically unresolved peptide. The discovery story is compelling. The pleiotropic biology is real. The longevity data in mice is remarkable. But the absence of a known receptor, the conflicting clinical data, and the nearly 50-year failure to identify a precursor gene make DSIP fundamentally different from most other peptides on this site. "Interesting biology" and "clinically useful sleep aid" remain separated by gaps that have not been bridged despite decades of research.
Test your understanding of DSIP biology, its enigmatic status, and the conflicting clinical evidence.
This profile is for educational and research purposes only. It is not medical advice, and nothing on it is a protocol, a recommendation, or an instruction for use in a person or an animal.
Athena Peptides Education does not prescribe, sell, or recommend any compound. Compounds discussed here are for laboratory research only and are not for human consumption. Always consult a qualified physician before making any decision about your health.