DSIP 5mg

What is DSIP ?

DSIP (delta sleep-inducing peptide, INN emideltide) is a nonapeptide first isolated from rabbits in 1977. It is studied in sleep, stress-hormone and circadian research. We supply it as lyophilised powder in 5mg and 10mg vials.

The sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), with a free acid C-terminus. The formula is C₃₅H₄₈N₁₀O₁₅, the molecular weight 848.8 g/mol and the CAS number 62568-57-4. Schoenenberger and Monnier isolated it from rabbit cerebral venous blood and named it for the delta-wave EEG activity it produced (PNAS, 1977).

No DSIP gene, parent protein or receptor has been isolated, and its natural occurrence is still unclear. Kovalzon and Strekalova (J Neurochem, 2006) called it a still unresolved riddle.

DSIP Research Applications

• Sleep EEG : in a double-blind test in 58 rabbits, only synthetic DSIP, of nine related peptides, enhanced delta and spindle EEG patterns (Schoenenberger and Monnier, 1977).
• Species : Graf and Kastin (1984) reported mainly delta sleep in rabbits, rats and mice, a stronger REM effect in cats, and a U-shaped dose curve.
• Stress axis : DSIP inhibited CRF-induced ACTH release from rat anterior pituitary in vitro, most strongly at 10 nM. Basal ACTH did not change (Okajima and Hertting, 1986).
• Replication : Kovalzon and Strekalova (2006) call the sleep-factor case weak. Some synthetic DSIP analogues promoted slow-wave sleep in rabbits and rats, but DSIP itself did not.

Graf and Kastin (1984) also list effects on electrophysiological activity, brain neurotransmitter levels, locomotor patterns and the withdrawal of neuropharmacological drugs. Much of this literature is decades old and poorly replicated, so DSIP suits hypothesis testing and replication work.

DSIP vs Conventional Sleep-Pathway Peptides

Established sleep-regulating peptides have a known gene, a precursor protein and a receptor. DSIP has none of the three on record, and its structure matches no known peptide family (Kovalzon and Strekalova, 2006). DSIP-like immunoreactivity sits in hypothalamic neurosecretory nuclei that are not particularly relevant to sleep regulation. The authors propose that an undiscovered DSIP-like peptide accounts for at least part of that signal and of DSIP's reported activity.

Research Overview

DSIP (Delta Sleep-Inducing Peptide) is a neuropeptide consisting of nine amino acids with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. First identified in 1977 from cerebral venous blood of rabbits during electrically induced sleep by Swiss researchers Schoenenberger and Monnier, DSIP has since been studied for its role in sleep architecture regulation, stress response modulation, and neuroendocrine activity. Research has examined DSIP's effects on circadian rhythm regulation, its interactions with the hypothalamic-pituitary axis, and its potential influence on cortisol and ACTH levels during stress responses. Studies have documented effects on delta wave sleep patterns, from which the peptide derives its name. DSIP research extends beyond sleep physiology into areas including opioid receptor modulation, withdrawal symptom attenuation, and free radical scavenging activity. The peptide's stability in serum and its ability to cross the blood-brain barrier make it a practical research tool in sleep physiology and chronobiology. Its effects on reducing corticotropin levels suggest involvement in stress-adaptive pathways, adding complexity to its pharmacological profile beyond simple sleep induction.

DSIP was isolated by Schoenenberger and Monnier, who reported recovering it from the cerebral venous blood of rabbits during electrically induced sleep and published the characterisation in 1977. The sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, an unusually acidic nonapeptide.

It is worth being direct about the state of the evidence, because DSIP is a compound where the name promises more than the literature delivers. No specific DSIP receptor has ever been identified, the original sleep-induction findings have proved difficult to replicate consistently, and its status as a genuine endogenous sleep factor remains contested nearly fifty years after its description. Much of the subsequent work has instead concerned effects some distance from sleep, including opioid withdrawal models, stress and corticotropin responses, and antioxidant activity.

That uncertainty is precisely why it remains an interesting research tool rather than a settled one, and it is stated plainly here rather than papered over with confident mechanism claims. DSIP is not an approved medicine in any jurisdiction and is supplied as lyophilised powder for in-vitro laboratory research only.

Storage and Reconstitution

Store DSIP powder at -20°C, away from light and moisture, for up to 24 months. After reconstitution, keep the solution at 2-8°C in a light-protected container and use it within 4 weeks. For longer storage, freeze single-use aliquots at -20°C and avoid repeated freeze-thaw cycles.

Vials are sold on their own, without bacteriostatic water for mixing or other supplies.

How to reconstitute and handle

Let the vial and the bacteriostatic water reach room temperature and swab both stoppers with alcohol. Add the water slowly down the inside wall of the vial and swirl gently until dissolved. Do not shake. The N-terminal tryptophan is sensitive to light, so work away from direct sunlight. It also absorbs at 280 nm, which allows a UV check of concentration. The solution should be clear and colourless.

• Handle under aseptic laboratory conditions using sterile equipment throughout reconstitution and aliquoting.
• Avoid repeated freeze-thaw cycles. Prepare measured aliquots from reconstituted stock for consistent experimental use.

For the full method, see the peptide reconstitution guide and the reconstitution calculator.

Research References

• Nuclear changes in cultured human dystrophic muscle (Experientia, 1977)
• Moducren once versus twice daily in mild to moderate hypertension (Pharmatherapeutica, 1984)
• Characterization of a delta-electroencephalogram (-sleep)-inducing peptide (Schoenenberger and Monnier, Proc Natl Acad Sci U S A, 1977)
• Delta sleep-inducing peptide (DSIP): a still unresolved riddle (Kovalzon and Strekalova, J Neurochem, 2006)
• Delta-sleep-inducing peptide (DSIP): a review (Graf and Kastin, Neurosci Biobehav Rev, 1984)
• DSIP inhibited CRF-induced ACTH secretion from rat anterior pituitary in vitro (Okajima and Hertting, Horm Metab Res, 1986)

Published research on DSIP is indexed on PubMed. See our full UK buyer's guide for DSIP and UK buyer's guide for DSIP 5mg.