DSIP

What is DSIP?

DSIP (Delta Sleep-Inducing Peptide) is a nonapeptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), molecular weight 848.8 g/mol, CAS 62568-57-4. It was isolated in 1977 by Schoenenberger and Monnier from the cerebral venous blood of rabbits in which slow-wave sleep had been induced by electrical stimulation of the intralaminar thalamus, and named for the delta-wave EEG activity that transfusion of the dialysate appeared to promote in recipient animals. Nearly five decades on, DSIP remains one of the most genuinely unresolved compounds in peptide research: no receptor has ever been identified, the gene encoding it has never been found in any genome, and attempts to confirm its endogenous existence by modern analytical methods have not succeeded. Replication of the original sleep findings has been inconsistent, with both positive and null results in animal and human EEG studies. It is precisely this contradictory record that keeps DSIP in use as a research subject. Supplied as lyophilised powder for in-vitro research use only.

DSIP vs Conventional Sleep-Pathway Peptides

The instructive contrast is between DSIP and the sleep-relevant peptide systems whose biology is actually established. Orexin-A and orexin-B act at defined receptors, OX1R and OX2R, their loss causes narcolepsy, and antagonists at those receptors are licensed medicines; melanin-concentrating hormone has mapped receptors and characterised REM-promoting circuitry; galanin and growth hormone releasing hormone have documented roles in sleep-active hypothalamic neurons. Against every one of those systems DSIP fails the basic tests: no receptor has been identified despite decades of searching, no precursor gene exists in any sequenced genome, and its presence in tissue has depended on immunoassays whose specificity was later questioned rather than on mass-spectrometric confirmation. Human studies through the 1980s and 1990s reported improved sleep in some trials and no effect in others, and the field never converged. Researchers should therefore treat DSIP not as a validated sleep-pathway ligand but as an open analytical and pharmacological question, and any experimental design should include the controls that the historical literature often lacked.

DSIP Research Applications

DSIP is studied across sleep physiology and chronobiology, where the original delta-wave EEG claims continue to be tested in rodent models, and in a scattered secondary literature that grew up around the peptide in the 1980s and 1990s: hypothalamic-pituitary axis interactions including reported effects on cortisol, ACTH and somatostatin secretion, stress-response paradigms, opioid receptor pathway interactions including reported modulation of opioid withdrawal in animal models, and free-radical scavenging and membrane-stabilising activity in oxidative stress models. A further strand uses DSIP itself as the analytical target, applying modern LC-MS methods to the still-open question of whether the peptide exists endogenously at all. Because the primary literature is old, methodologically uneven and contradictory, DSIP is best treated as a compound for hypothesis-testing and replication work rather than as a tool with an established mechanism.

Reconstitution Guide

Allow vials to reach room temperature, then sterilise the rubber stopper of both the peptide vial and the bacteriostatic water vial with an alcohol swab. Slowly draw your bacteriostatic water into a sterile insulin syringe, then inject it gently down the inner glass wall of the peptide vial, never directly onto the lyophilised powder. Once added, gently swirl the vial in a slow circular motion until fully dissolved. Never shake or vortex. The N-terminal tryptophan is the oxidation- and light-sensitive residue in this sequence, so reconstitute away from direct sunlight and fluorescent lighting; it also provides a usable chromophore for concentration checks by UV absorbance at 280 nm. The solution should be clear and colourless. Label the vial with the reconstitution date and refrigerate immediately.

See our full peptide reconstitution guide and reconstitution calculator for step-by-step protocol.

Storage Instructions

Lyophilised vials should be stored at -20°C, protected from light and moisture, and remain stable for up to 24 months. Once reconstituted with bacteriostatic water, store the solution at 2-8°C in a light-protected container and use within approximately 4 weeks, preparing single-use aliquots at -20°C for longer storage. Tryptophan oxidation is the degradation route to monitor, resolving as a new RP-HPLC peak after extended or light-exposed storage, and repeated freeze-thaw cycling accelerates it, so keep aliquots single-use and amber or foil-wrapped. Handle under sterile laboratory conditions throughout.

Frequently Asked Questions

Research References

• Delta sleep-inducing peptide, discovery and characterisation (Experientia, 1977)
• DSIP and sleep regulation, review (Pharmacol Biochem Behav, 1984)

Related Research Compounds

• → Selank 10mg
• → Semax 10mg
• → Bacteriostatic Water 10ml