DSIP Safety Profile

Delta sleep-inducing peptide (DSIP; sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu; PubChem CID 68816) is a nine-residue nonapeptide first isolated in 1974 and studied over five decades across sleep biology, neuroprotection, and stress physiology. It carries no approved therapeutic indication in any major regulatory jurisdiction as of April 2026. The safety information available is therefore not derived from a regulatory toxicology package but from academic preclinical studies in rodents, limited human observational data, and clinical reports from opioid detoxification trials.

This page consolidates available safety-relevant data: acute and chronic preclinical findings, adverse events reported in human studies, populations that may be at elevated risk, and potential pharmacological interactions. All citations are identified by PMID.

DSIP (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu). PubChem CID 68816. MW 848.8 Da. Nonapeptide with net negative charge at physiological pH; serine-7 phosphorylation site.

Regulatory and Approval Status

DSIP is not approved by the FDA, EMA, Health Canada, or equivalent agencies for any indication. No investigational new drug (IND) application, clinical trial authorization (CTA), or equivalent regulatory filing for DSIP appears in public databases. ClinicalTrials.gov (queried April 2026) contains no registered trials with DSIP as the primary investigational agent.

The consequence for safety assessment is significant: the GLP toxicology studies that regulatory agencies require before human trials (single-dose and repeat-dose toxicology, genotoxicity, reproductive toxicology, carcinogenicity) have not been published in the peer-reviewed literature for DSIP. All safety inference comes from non-GLP academic experiments and human use outside structured regulatory oversight.

Preclinical Toxicology

Acute Toxicity

No formal LD50 determination for DSIP appears in indexed literature. The 1986 review by Graf and colleagues (PMID: 3550726; Peptides, 1986) summarized the state of DSIP safety at the time: the peptide had been administered to rats and rabbits across a range of doses and routes without lethal events or gross organ toxicity at pharmacologically active doses. The absence of formal LD50 data reflects the academic rather than pharmaceutical trajectory of DSIP research.

DSIP administered intracerebroventricularly (ICV) or into specific brain nuclei in rodents produces pharmacological effects at nanomolar concentrations. A study by Shandra et al. (PMID: 8581045; Fiziol Zh Im I M Sechenova, 1995) evaluated direct DSIP injection into the rat substantia nigra and reported an inducible rotational syndrome, a behavioral sign of asymmetric dopaminergic activation, at the injection site. A companion study (PMID: 9162398; Fiziol Zh Im I M Sechenova, 1996) characterized this as a site-specific effect: rotational behavior was observed when DSIP was injected into the reticular subdivision of the substantia nigra pars reticulata. These findings are relevant to intracranial administration only and do not reflect systemic safety at peripheral routes.

Chronic and Subchronic Rodent Studies

The most informative chronic exposure data come from aging rodent studies where DSIP was administered over extended periods.

Bondarenko group (aging Wistar and Sprague-Dawley rats). A series of papers from Bondarenko, Sorokina, Kutilin, and colleagues examined DSIP administered repeatedly over weeks to months in aged rats. Bondarenko et al. (PMID: 22866315; Bull Exp Biol Med, 2012) did not report any hematological, biochemical, or histopathological toxicity signals in animals receiving DSIP. Outcomes were positive for target tissues. Kutilin et al. (PMID: 25257425; Bull Exp Biol Med, 2014) similarly found no adverse markers across hepatic and renal profiles. These studies were not designed as formal toxicology studies and did not include histopathological examination of a comprehensive organ panel, so negative findings are informative but not conclusive.

Lifespan and spontaneous tumor incidence in SHR mice. Popovich, Voitenkov, and Anisimov (PMID: 12782416; Mech Ageing Dev, 2003) administered Deltaran, a DSIP-containing preparation, to female SHR mice over their lifespan. Spontaneous tumor incidence was monitored at necropsy. The Deltaran-treated group did not show elevated spontaneous tumor rates relative to controls; mean and maximum lifespan were modestly prolonged. This is a single-study observation in an inbred mouse strain prone to spontaneous neoplasia, and it does not constitute a carcinogenicity study under ICH S1B standards. However, the data do not suggest a pro-oncogenic signal.

A broader review by Anisimov and Khavinson (PMID: 19670728; Vopr Onkol, 2009) encompassing 35 years of peptide bioregulator research included DSIP-related data and concluded that peptide bioregulators, as a class, did not increase tumor incidence in the models evaluated. Again, this is a narrative review rather than a primary study; individual findings require independent verification.

Hepatic Safety in Stress Models

Bobyntsev, Kryukov, and Belykh (PMID: 26902351; Bull Exp Biol Med, 2016) evaluated hepatocyte function in rats under restraint stress. DSIP administration reduced aminotransferase (ALT/AST) elevation in the stressed group and normalized oxidative stress indices. Belykh et al. (PMID: 26470489; Ross Fiziol Zh, 2015) found the same hepatoprotective pattern in foot-shock stress. These studies indicate that DSIP does not exert hepatic toxicity at the doses used and may, if anything, buffer glucocorticoid-driven hepatocyte damage. Neither study examined DSIP’s hepatic effects at supraphysiological doses.

Adverse Events in Human Exposure

Opioid Detoxification Trials

The most structured human safety data for DSIP come from two studies in opioid-dependent patients undergoing detoxification.

Backmund et al. (1998). This open clinical trial (PMID: 9617990; J Clin Psychopharmacol, 1998) enrolled 22 patients dependent on heroin or prescription opioids. DSIP was administered intravenously over several days as an adjunct to standard detoxification. The authors reported that DSIP was generally well tolerated. Mild transient sedation and mild nausea were noted in some participants. No serious adverse events, respiratory depression, cardiovascular events, or seizures were attributed to DSIP. Withdrawal symptom scores improved in the treated group relative to historical comparison cohorts, though the uncontrolled design limits causal attribution.

Soyka et al. (1997). A companion report (PMID: 9137140; Am J Psychiatry, 1997) from a related group also described DSIP use in opioid detoxification. Tolerability was again characterized as acceptable, with no severe adverse events. The study was small and non-randomized. These two reports represent the most complete human adverse-event data available for DSIP.

Electrophysiological Observation in Surgical Patients

Pomfrett, Dolling, and Anders (PMID: 19142086; Eur J Anaesthesiol, 2009) studied DSIP as an adjunct to isoflurane anesthesia in elective surgical patients. Intravenous DSIP reduced bispectral index (BIS) values and altered EEG spectral power, indicating deeper CNS depression. Heart rate variability was also affected. No adverse events attributable to DSIP were reported in this prospective study, but the deepened sedation signal is a safety-relevant pharmacodynamic finding: DSIP augmented anesthetic CNS depression measurably, which has implications for combined use with sedative agents.

Sleep Studies and Insomnia Patients

Schneider-Helmert and colleagues conducted intranasal DSIP administration in insomnia patients through the 1980s (PMID: 3582201; Dtsch Med Wochenschr, 1987). Reported adverse events were absent or minimal across this work. Hruz et al. (PMID: 11763019; J Clin Psychopharmacol, 2001) administered intranasal DSIP in a study measuring P300 event-related potentials and similarly reported no adverse events. These are small studies with short follow-up and no standardized adverse-event monitoring, so absence of reported events should not be interpreted as absence of risk.

Elevated Endogenous Levels in Renal Failure

Hegbrant et al. (PMID: 1667974; Blood Purif, 1991) measured plasma DSIP in patients receiving chronic hemodialysis and found markedly elevated levels compared with healthy controls. A follow-up study (PMID: 1337953; Scand J Urol Nephrol, 1992) from the same group measured DSIP alongside corticotropin-releasing hormone (CRH) and opioid peptides during erythropoietin treatment in hemodialysis patients. The accumulation of DSIP in chronic renal failure indicates impaired clearance. Exogenous DSIP administered to patients with renal insufficiency could reach substantially higher and more prolonged plasma concentrations than in healthy individuals. This is a pharmacokinetic safety consideration, not a documented adverse event, but it identifies renal impairment as a clinically relevant variable in any future development program.

Pharmacokinetic Determinants of Safety

flowchart TD
    A["Exogenous DSIP\n(peripheral route)"] --> B["Serum peptidase\ndegradation\n(rapid; t½ minutes)"]
    A --> C["Intact DSIP reaches\ncirculation"]
    C --> D["BBB transport\n(documented; mechanism unclear)\n(Banks WA, PMID:25805003)"]
    D --> E["CNS compartment\nPharmacological effects"]
    C --> F["Peripheral organ distribution\n(liver, kidney, gut)\n(Graf MV, PMID:6548030)"]
    B --> G["Degradation fragments\n(biological activity uncertain)"]
    E --> H["HPA axis modulation\n(CRH suppression)"]
    E --> I["Opioid system interaction\n(enkephalin release)"]
    E --> J["Sleep architecture\nalternation"]
    F --> K["Renal clearance\n(impaired in ESRD;\nPMID:1667974)"]

DSIP is rapidly degraded by serum peptidases. The unmodified nonapeptide has a plasma half-life estimated in minutes after intravenous administration, based on extrapolation from animal pharmacokinetic data reviewed by Banks and colleagues (PMID: 25805003; Peptides, 2015). This short half-life limits systemic bioavailability and may partly explain inconsistencies in human efficacy data; it also constrains the duration of any adverse pharmacological effect following peripheral administration. The phosphorylated analog (pDSIP) shows reduced peptidase susceptibility and is biologically more active in several models (PMID: 30107169), which implies a different safety and exposure profile relative to the native peptide.

Degradation fragments of DSIP may themselves be biologically active. Graf et al. (PMID: 6548030; Proc Soc Exp Biol Med, 1984) demonstrated that DSIP-immunoreactive material in peripheral organs exists in dissociable higher-molecular-weight forms, suggesting endogenous processing complexity. The pharmacological activity of these processed forms has not been systematically characterized.

Renal clearance is impaired in end-stage renal disease (ESRD). Hepatic clearance has not been formally studied. Patients with severe hepatic impairment represent an unknown-exposure population.

Pharmacological Interaction Concerns

Opioid System Interactions

DSIP stimulates the release of immunoreactive Met-enkephalin from rat lower brainstem slices in vitro (PMID: 2706459; as cited in Graf 1986 review). This enkephalin-releasing activity suggests indirect engagement of the endogenous opioid system. Yehuda et al. (PMID: 3679693; Int J Neurosci, 1987) demonstrated that DSIP’s effects on pain threshold in rats were not reversed by naloxone, establishing that direct mu-opioid receptor agonism is not the mechanism. However, indirect potentiation of endogenous opioid tone could theoretically amplify the effects of exogenous opioid analgesics or produce additive CNS depression.

In the rodent alcohol withdrawal model, Viglinskaia et al. (PMID: 2268715; Biull Eksp Biol Med, 1990) found that DSIP normalized sleep electrophysiology during alcohol withdrawal, consistent with GABA-A or NMDA pathway modulation during withdrawal states. Combined administration with alcohol, benzodiazepines, or other CNS depressants in humans has not been studied under controlled conditions.

HPA Axis and Corticosteroid Interactions

DSIP modulates the hypothalamic-pituitary-adrenal (HPA) axis. Several preclinical studies show that DSIP reduces CRH-driven corticosteroid output in stressed animals (reviewed in Bobyntsev et al., PMID: 26902351). This HPA-dampening effect creates a theoretical interaction with exogenous glucocorticoid therapy: if DSIP suppresses CRH signaling, it could alter the dynamics of glucocorticoid negative feedback or mask adrenal insufficiency. This interaction has not been studied experimentally.

CNS Depressants and Anesthetics

The Pomfrett 2009 study (PMID: 19142086) provides direct evidence that intravenous DSIP deepens isoflurane anesthesia as measured by EEG and BIS. This is the strongest human pharmacodynamic safety signal in the published literature. Combined use of DSIP with volatile anesthetics, propofol, benzodiazepines, or other sedative-hypnotic agents should be considered a potential source of additive CNS depression. The magnitude of this interaction and its dose dependence in humans are not characterized.

Antioxidant Enzyme Induction and Cytochrome P450

DSIP upregulates superoxide dismutase, catalase, and glutathione peroxidase in rodent brain and peripheral tissues (PMID: 25257425). Antioxidant enzyme induction is generally protective but could theoretically modulate the oxidative metabolism of co-administered drugs if hepatic cytochrome P450 (CYP) activity is affected. CYP enzyme induction or inhibition by DSIP has not been examined in any published study.

Special Populations and Potential Contraindications

The table below summarizes populations for whom available data suggest either known or theoretical safety concerns. None of these are formal contraindications, as no regulatory review has occurred.

DSIP Immunoreactivity in Small-Cell Lung Cancer

Paulin et al. (PMID: 1318772; C R Acad Sci III, 1992) demonstrated DSIP immunoreactivity in a human small-cell lung carcinoma (SCLC) cell line, suggesting that some neuroendocrine tumors may produce DSIP-like material. Whether exogenous DSIP would exert autocrine or paracrine effects in SCLC or related neuroendocrine malignancies has not been investigated. This is a theoretical concern rather than an established risk; it warrants mention because neuroendocrine tumors are a biologically plausible setting for dysregulated neuropeptide effects.

Dose-Adverse Event Relationship

No dose-response relationship for adverse effects has been established in humans. Preclinical studies used doses spanning several orders of magnitude depending on route (nanomolar ICV versus microgram-per-kilogram intraperitoneal). In the Backmund 1998 opioid detoxification trial (PMID: 9617990), DSIP was administered intravenously over several days; the doses used were not disclosed in full detail in the abstract-accessible record. The Schneider-Helmert 1980s intranasal studies similarly did not publish dose-response adverse-event data.

The substantia nigra microinjection studies (PMID: 8581045, PMID: 9162398) indicate that site-specific CNS administration at inappropriate locations produces behavioral toxicity (rotational syndrome). This is an anatomical-targeting concern for any intracranial delivery approach, not a systemic safety concern at peripheral routes.

Evidence Gaps

The following safety-relevant questions remain unanswered in the published literature as of April 2026:

1. No formal LD50 or NOAEL (no-observed-adverse-effect level) for any species or route. Regulatory-standard single and repeat-dose toxicology studies have not been published.
2. No genotoxicity data. Ames test, chromosomal aberration assay, and in vivo micronucleus test results are absent from the literature.
3. No reproductive or developmental toxicology. Effects on fertility, embryotoxicity, and teratogenicity have not been studied.
4. No immunogenicity assessment. DSIP is a foreign peptide in the context of therapeutic administration. Antibody formation, hypersensitivity, and anaphylaxis risk have not been evaluated in any human trial.
5. No controlled drug-drug interaction studies. All interaction concerns identified above are theoretical or inferred from mechanism; no prospective DDI study exists.
6. Pediatric and geriatric pharmacokinetics are unstudied. Age-related differences in peptidase activity and renal clearance may substantially alter exposure.
7. Long-term human exposure data are absent. The longest human studies administering DSIP span days (opioid detox) to weeks (insomnia studies). Organ-level effects of months-to-years exposure are entirely unknown.

Summary

DSIP’s available safety record is thin by regulatory standards. Acute preclinical data, chronic rodent aging studies, and limited human opioid detoxification and sleep trials have not identified severe or dose-limiting toxicity at the doses and routes studied. The peptide’s short plasma half-life after peripheral administration likely limits cumulative exposure and may contribute to the favorable short-term tolerability observed.

The primary pharmacologically driven safety concerns arise from DSIP’s documented interactions with the opioid system (enkephalin release; PMID: 2706459), HPA axis (CRH modulation; PMID: 26902351), and CNS depressant pathways (additive sedation with isoflurane; PMID: 19142086). These mechanism-based risks require prospective evaluation before any clinical development proceeds. Populations with impaired renal clearance accumulate endogenous DSIP (PMID: 1667974) and represent an unknown-risk group for exogenous exposure. Standard regulatory toxicology studies, genotoxicity panels, immunogenicity assessment, and controlled drug-drug interaction studies are absent from the public domain.

This page summarizes published research for scientific and educational reference. It does not constitute medical advice. DSIP has no approved therapeutic indication.

See also

More on Dsip:

• Dsip research overview
• Dsip: Mechanism of action
• Dsip: Clinical & preclinical evidence
• Dsip: Pharmacokinetics
• Dsip: Dose-response

Related peptide family:

• Nootropic Peptides

Pathway context:

• Neuropeptides & Cognitive Function

Head-to-head comparisons:

• Dsip vs GHK-Cu
• Selank vs Dsip
• Semax vs Dsip