DSIP — Delta Sleep-Inducing Peptide | Endogenous Nonapeptide (WAGGDASGE) for Sleep Architecture Research
Research-Grade Compound
DSIP (delta sleep-inducing peptide) is an endogenous nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), first isolated in 1977 from the cerebral venous blood of rabbits undergoing induced slow-wave sleep. Molecular formula C35H48N10O15, molecular weight 848.8 Da, CAS 62568-57-4.
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What is DSIP?
DSIP (delta sleep-inducing peptide) is an endogenous nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), first isolated in 1977 from the cerebral venous blood of rabbits undergoing induced slow-wave sleep. Molecular formula C35H48N10O15, molecular weight 848.8 Da, CAS 62568-57-4.
The name records the assay that found it, not a mechanism anyone has since pinned down. Monnier and Schoenenberger separated a fraction of blood from sleeping animals, transferred it to recipient animals, observed an increase in delta-frequency EEG activity, and named the responsible peptide accordingly. That is a functional definition from a single preparation, and nearly fifty years later it remains the strongest claim in the compound record.
DSIP is found endogenously in the hypothalamus, limbic structures, pituitary and plasma, and it crosses the blood-brain barrier — a property uncommon among peptides of this size and part of why it stayed interesting after the sleep findings proved hard to replicate. What DSIP does not have is a receptor. No DSIP receptor has been cloned or characterised, no consensus binding site exists, and every mechanism described below is an association rather than a pathway. Among the compounds in the Peptide.Express catalog, DSIP is the one where the gap between name recognition and characterised pharmacology is widest.
How Does DSIP Work? Mechanism of Action
Start with what is absent, because it governs how everything else should be read: there is no identified DSIP receptor. Without a binding target, the reported effects are observations of what happens after administration, not descriptions of a signalling cascade. Any account of DSIP mechanism that reads as confidently as a GPCR mechanism is overstating the evidence.
On sleep architecture, the original finding was increased delta-frequency (slow-wave) EEG power in rabbit and rat preparations. Replication across laboratories has been uneven — some groups reproduced an effect on slow-wave activity, others found none, and differences in species, administration route and EEG scoring criteria account for some but not all of the divergence. What DSIP does not appear to be is a conventional sedative: it does not behave as a GABA-A receptor agonist and does not produce the pharmacological signature of benzodiazepines or barbiturates in standard assays. Whatever it modulates, it modulates upstream of the classical sedative targets.
Outside sleep, the reported associations are broad and individually thin. Attenuation of CRF-induced corticosterone release appears in stress-axis models, though the same evidence found no effect on ACTH-induced corticosterone release specifically. Effects on LH secretion, interactions with somatostatin signalling, opioid-system interactions in analgesia preparations, and antioxidant activity have all been described. Each of these rests on a small number of studies rather than a replicated body of work, and none has been tied back to a receptor.
Blood-brain barrier transport is the mechanistic finding that has held up best. DSIP crosses into the CNS, which makes it usable in designs where a systemically administered compound needs to reach central tissue. Against that, plasma stability is poor — DSIP is degraded rapidly by circulating peptidases — so the exposure achieved after systemic administration is brief and hard to characterise. Researchers designing DSIP studies should treat both the transport and the degradation as first-order variables rather than background details.
Research Applications of DSIP
Sleep Architecture and EEG Research
- Delta-power quantification: spectral analysis of slow-wave EEG activity in rodent and rabbit preparations is the endpoint the compound was originally named for.
- Sleep-stage transition mapping: measuring changes in the distribution of sleep stages rather than total sleep duration is the more informative design given the inconsistency of the earlier literature.
- Sedative-mechanism exclusion: running DSIP alongside a GABA-A agonist arm distinguishes slow-wave modulation from general sedation.
Neuroendocrine and Stress-Axis Models
- Corticotropin-releasing signalling: attenuation of CRF-induced corticosterone release is among the more frequently reported non-sleep effects, though from a small evidence base, with no effect observed on ACTH-induced output specifically.
- Gonadotropin interaction studies: reported effects on LH secretion place DSIP loosely alongside the HPG-axis compounds, without a mechanism connecting the two.
- Opioid and somatostatin system interaction: analgesia and neuroendocrine preparations examining whether DSIP effects are blocked by opioid antagonists.
Blood-Brain Barrier Transport and Peptide Stability
- CNS penetration studies: DSIP is used as a reference compound in peptide transport research because it crosses the barrier at a measurable rate.
- Plasma degradation kinetics: rapid peptidase cleavage limits systemic exposure, and characterising that decay is necessary before any dose-response interpretation.
- Analog stabilisation work: modified DSIP sequences are studied primarily to extend plasma half-life rather than to alter target engagement, since no target has been identified.
DSIP vs Melatonin
| Feature | DSIP | Melatonin |
|---|---|---|
| Chemical class | Nonapeptide (WAGGDASGE) | Indoleamine, tryptophan-derived small molecule |
| Molecular weight | 848.8 Da | Small molecule, far below peptide range |
| Source of discovery | Cerebral venous blood of sleeping rabbits, 1977 | Pineal gland extract, 1958 |
| Receptor | None identified | MT1 and MT2 G protein-coupled receptors |
| Primary research framing | Slow-wave (delta) EEG power | Circadian phase shifting and entrainment |
| Endogenous rhythm | Not established | Strongly circadian, suppressed by light exposure |
| Evidence base | Sparse and inconsistently replicated | Large, replicated across species and laboratories |
| Regulatory status (US) | Research compound, no approval | Marketed as a dietary supplement |
These two get filed together in consumer discussion under the heading of sleep compounds, and mechanistically that is a category error — which is exactly why the comparison is worth drawing. Melatonin has cloned receptors, a characterised circadian role and decades of replicated work behind it. DSIP has a name derived from one 1977 preparation and no identified receptor at all. A study design that treats them as members of the same pharmacological class starts from a false premise.
DSIP Technical Specifications
| Compound Name | DSIP (delta sleep-inducing peptide) |
|---|---|
| Common Synonyms | Delta sleep-inducing peptide, delta sleep peptide, DSIP peptide |
| Classification | Endogenous linear nonapeptide |
| Amino Acid Sequence | Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE) |
| Amino Acid Count | 9 (nonapeptide) |
| CAS Number | 62568-57-4 |
| Molecular Formula | C35H48N10O15 |
| Molecular Weight | 848.8 Da |
| Receptor Target | None identified — no DSIP receptor has been cloned or characterised |
| Blood-Brain Barrier | Crosses the barrier at a measurable rate |
| Endogenous Distribution | Hypothalamus, limbic structures, pituitary, plasma |
| First Isolated | 1977, from cerebral venous blood of rabbits in induced slow-wave sleep |
| Purity | ≥99% by HPLC |
| Purity Confirmation | LC-MS/MS molecular weight verification |
| Endotoxin Testing | LAL (Limulus Amebocyte Lysate) method |
| Physical Form | Lyophilized powder |
| Appearance | White to off-white powder |
| Reconstitution | Bacteriostatic water or sterile 0.9% sodium chloride |
| Storage (lyophilized) | -20°C, desiccated, protected from light |
| Storage (reconstituted) | 2–8°C, use within 14–28 days |
| Shelf Life | 24 months from manufacture (lyophilized) |
| Testing Methods | HPLC, LC-MS/MS, LAL Endotoxin |
| Documentation | Certificate of Analysis (CoA) per batch |
| FDA Status | Not approved for human use |
| Intended Use | In-vitro laboratory research only |
How to Reconstitute DSIP for Research
DSIP is a small, highly polar peptide with two acidic residues, and it dissolves quickly — often within 30 seconds of gentle swirling. The tryptophan at position 1 makes the reconstituted solution light-sensitive, so keep the vial covered rather than parked under bench lighting.
- Allow the vial to reach room temperature before opening.
- Draw the calculated volume of bacteriostatic water. For a 10 mg vial, 2 mL yields 5 mg/mL and 5 mL yields 2 mg/mL.
- Swab the septum with alcohol and allow 30 seconds to dry.
- Inject the diluent slowly against the inner vial wall.
- Swirl gently until dissolution is complete. DSIP goes into solution faster than most peptides in this catalog — do not add agitation it does not need.
- Confirm the solution is clear and colorless with no visible particulate.
- Label with the reconstitution date and resulting concentration.
- Store at 2–8°C, protected from light, and use within 14–28 days.
Diluent: bacteriostatic water for peptide reconstitution. Full protocol: step-by-step peptide reconstitution guide. Concentration maths: peptide reconstitution calculator.
Frequently Asked Questions — DSIP
What is DSIP peptide?
What does delta sleep-inducing peptide do in research models?
What is DSIP mechanism of action?
Is DSIP related to GABA or standard sedative pathways?
Does DSIP cross the blood-brain barrier?
What is the difference between DSIP and melatonin?
Why is DSIP considered under-characterised?
How stable is DSIP in plasma?
Where is DSIP found endogenously?
What purity standard and testing does Peptide.Express apply to DSIP?
How should DSIP be stored before and after reconstitution?
Where is the Certificate of Analysis for DSIP?
Research References
- Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram(-sleep)-inducing peptide. Proc Natl Acad Sci U S A. 1977. Read Schoenenberger and Monnier's 1977 isolation and characterization of DSIP
- Banks WA, Kastin AJ, Coy DH. Evidence that [125I]N-Tyr-delta sleep-inducing peptide crosses the blood-brain barrier by a non-competitive mechanism. Brain Res. 1984. Read Banks, Kastin and Coy on DSIP blood-brain barrier transport
- Graf MV, Kastin AJ, Coy DH, Fischman AJ. Delta-sleep-inducing peptide reduces CRF-induced corticosterone release. Neuroendocrinology. 1985. Read Graf et al. on DSIP's effect on CRF-induced corticosterone release
All products are sold for in-vitro laboratory research use only. Not intended for human consumption, clinical use, or veterinary use. Peptide.Express makes no medical claims. Consult the published literature for research application guidance.