What is DSIP?
DSIP is short for delta sleep-inducing peptide. It is a nine-residue peptide with the sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. It was isolated in Basel in the 1970s from the cerebral venous blood of rabbits. The blood was drawn during electrical stimulation of the thalamus. The isolated fraction was then given to recipient rabbits. In them it produced a delta electroencephalogram (EEG) pattern. The peptide is named for that pattern (Schoenenberger and Monnier, 1977; Monnier et al., 1977).
So the name reflects the assay in which the peptide was found, not a proven function. Nearly five decades later, no DSIP gene, precursor protein or receptor has been found. A review in the Journal of Neurochemistry set out this open question in detail (Kovalzon and Strekalova, 2006). Disguised Alpha supplies DSIP as a lyophilized powder for laboratory research use only. Nothing on this page is guidance for use in people.
DSIP reference data
| Property | Value |
|---|---|
| Name | DSIP (delta sleep-inducing peptide) |
| Aliases | Emideltide, delta sleep peptide, DSIP nonapeptide (PubChem CID 68816) |
| Sequence | Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE, PubChem CID 68816) |
| Peptide class | Linear nonapeptide, no identified receptor |
| Molecular formula | C₃₅H₄₈N₁₀O₁₅ |
| Molecular weight | 848.8 g/mol |
| CAS number | 62568-57-4 (PubChem CID 68816) |
| Known analogs in the literature | Phosphorylated DSIP (serine 7), des-Trp1-DSIP, D-Ala substituted analogs |
| Form | Lyophilized powder |
| Size carried | 10MG |
| Testing | Third-party tested, with the certificate for each lot published on the product page and in the COA portal |
Formula, molecular weight, CAS number and size come from the DSIP product page. Sequence and aliases come from PubChem. Check identity and measured content against your lot's certificate.
What the research covers
Published work on DSIP falls into six areas. Each summary below states the model used. Readers should know up front that the evidence base is unusual. Most of the early work came from the one Basel group that isolated the peptide. Outside attempts to repeat that work were mixed or negative. A large share of the later papers appear in Russian-language gerontology journals from a few labs.
Isolation and sequence
The first study split dialysate from rabbit cerebral venous blood into fractions. The team then made synthetic DSIP. They also made five possible breakdown products and two analogs with substituted residues. All nine synthetic peptides were infused into the cerebral ventricles of 58 rabbits under double-blind conditions. Fast Fourier analysis of neocortical and archicortical EEG recordings showed stronger delta and spindle patterns.
This was seen only with the intact nonapeptide (Schoenenberger and Monnier, 1977). Two early reviews from the same period collect the follow-up work on reported effects beyond the EEG. These include thermoregulation, blood pressure and circadian patterns (Graf and Kastin, 1984; Graf and Kastin, 1986).
Replication attempts in rodents
An outside group in Zurich gave DSIP to rats, both systemically and into the lateral and third ventricles. The group recorded motor activity and EEG. Neither sleep nor delta-band power rose significantly in the two hours after the peptide was given. The authors concluded that the peptide did not qualify as a specific sleep-promoting substance. They did note smaller changes in dark-time motor activity (Tobler and Borbely, 1980). This split between the first lab and outside groups is the central feature of DSIP research.
Human studies
Two small controlled studies looked at the peptide in people with chronic insomnia. One was a double-blind matched-pairs study of 16 patients, with peptide or placebo given on three nights. Polysomnography showed higher sleep efficiency and shorter latency than placebo. But the authors judged the differences weak and partly due to a change in the placebo group. They concluded that short-term use in chronic insomnia was unlikely to matter clinically (Bes et al., 1992). A crossover study used the same schedule.
It found increases in total and non-REM sleep time, but these were already present at baseline. The authors judged the change of little clinical significance (Monti et al., 1987). A later randomized study in 24 surgical patients used the peptide with volatile anesthesia. It found the opposite of the expected direction. Heart rate rose and heart-rate variability fell. Delta rhythm dropped and bispectral index rose. The authors read this as a lightening of anesthetic depth (Pomfrett et al., 2009).
Stability, transport and clearance
An enzyme immunoassay study in dogs, a monkey and rats found rapid clearance from plasma. Mean half-life was about four minutes in dogs and about two minutes in rats (Kato et al., 1984). Incubation in human and rat blood released material that eluted like tryptophan. This points to cleavage of the N-terminal residue.
Labeled analogs broke down more slowly and formed complexes (Graf et al., 1987). Transport studies in dogs found measurable entry into cerebrospinal fluid. Entry was linked to plasma level, plasma half-life and lipophilicity (Banks et al., 1986; Banks et al., 1982). A cultured brain microvessel endothelial model found non-saturable, temperature-insensitive flux. This fits simple diffusion (Raeissi and Audus, 1989).
What DSIP immunoassays actually detect
Much of the claimed tissue distribution of DSIP rests on antibody tests for DSIP-like immunoreactivity. One of those larger immunoreactive forms was isolated directly from porcine brain. It proved to be a 77-residue peptide with a sequence unrelated to DSIP. Yet antiserum raised against DSIP still recognizes it (Sillard et al., 1993). This is a standing caution for anyone reading older distribution data.
Stress, hypoxia and injury models
A Russian group studied isolated rat brain mitochondria. It found that the peptide raised phosphorylating respiration and the respiratory control ratio. Giving the peptide first also prevented the drop in mitochondrial respiratory activity after experimental hypoxia (Khvatova et al., 2003). Another study used a rat middle cerebral artery occlusion model.
The peptide was given through the nose before and after the occlusion. It did not significantly change infarct volume. But rotarod performance recovered more in the peptide group (Tukhovskaya et al., 2021). More recent work has focused on fusion constructs rather than on free DSIP. These constructs are meant to increase brain entry (Mu et al., 2024).
Key studies
- Schoenenberger GA, Monnier M. "Characterization of a delta-electroencephalogram (-sleep)-inducing peptide." Proc Natl Acad Sci U S A. 1977. PMID 265572. DOI 10.1073/pnas.74.3.1282. Rabbit model: isolation, synthesis and double-blind EEG comparison of nine synthetic peptides.
- Tobler I, Borbely AA. "Effect of delta sleep inducing peptide (DSIP) and arginine vasotocin (AVT) on sleep and motor activity in the rat." Waking Sleeping. 1980. PMID 7405185. Rat model: independent replication attempt with EEG and motor activity, negative for sleep.
- Banks WA, et al. "Delta sleep-inducing peptide crosses the blood-brain-barrier in dogs: some correlations with protein binding." Pharmacol Biochem Behav. 1982. PMID 6897451. DOI 10.1016/0091-3057(82)90486-5. Dog model: entry into cerebrospinal fluid and reversible plasma protein binding.
- Kato N, et al. "Development of an enzyme immunoassay for delta sleep-inducing peptide (DSIP) and its use in the determination of the metabolic clearance rate of DSIP administered to dogs." Neuroendocrinology. 1984. PMID 6379493. DOI 10.1159/000123952. Dog, monkey and rat: assay development and plasma clearance.
- Monti JM, et al. "Study of delta sleep-inducing peptide efficacy in improving sleep on short-term administration to chronic insomniacs." Int J Clin Pharmacol Res. 1987. PMID 3583493. Human clinical study: double-blind crossover with polysomnography.
- Graf MV, et al. "Degradation and aggregation of delta sleep-inducing peptide (DSIP) and two analogs in plasma and serum." Peptides. 1987. PMID 3628078. DOI 10.1016/0196-9781(87)90031-3. In vitro: breakdown in human, rat and dog blood.
- Bes F, et al. "Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study." Neuropsychobiology. 1992. PMID 1299794. DOI 10.1159/000118919. Human clinical study: 16 patients, matched pairs, polysomnography.
- Sillard R, et al. "A novel 77-residue peptide from porcine brain contains a leucine-zipper motif and is recognized by an antiserum to delta-sleep-inducing peptide." Eur J Biochem. 1993. PMID 8375381. DOI 10.1111/j.1432-1033.1993.tb18160.x. Porcine brain extract: isolation and sequencing of a cross-reacting peptide.
- Kovalzon VM, Strekalova TV. "Delta sleep-inducing peptide (DSIP): a still unresolved riddle." J Neurochem. 2006. PMID 16539679. DOI 10.1111/j.1471-4159.2006.03693.x. Review: state of the evidence and the missing gene, protein and receptor.
- Pomfrett CJ, et al. "Delta sleep-inducing peptide alters bispectral index, the electroencephalogram and heart rate variability when used as an adjunct to isoflurane anaesthesia." Eur J Anaesthesiol. 2009. PMID 19142086. DOI 10.1097/EJA.0b013e32831c8644. Randomized human study in 24 patients with EEG, bispectral index and heart-rate variability.
Handling and storage of lyophilized DSIP
General lab practice for this material:
- Store the lyophilized powder at -20°C, protected from light, until use. Storage guidance is on the product page.
- Let the sealed vial reach room temperature before opening. This keeps moisture from condensing on the powder.
- In blood, the first and fastest reported breakdown step is loss of the N-terminal tryptophan (Graf et al., 1987). So plan analytical methods that separate intact DSIP from tryptophan and des-Trp1-DSIP. Do not rely on total immunoreactivity.
- Plasma clearance was measured in minutes in several species (Kato et al., 1984). This matters for sampling schedules in any in vivo design.
- After reconstitution, keep solutions at 2 to 8°C and protected from light. Split stock into single-use aliquots to avoid freeze/thaw cycles.
- Record the lot number and keep its certificate with your notes. For quantitative work, use the measured content and formula on the certificate, not the label mass.
Frequently asked questions
What is DSIP?
DSIP is a synthetic nine-residue peptide. It was first isolated from rabbit cerebral venous blood in the 1970s and described in 1977 (Schoenenberger and Monnier, 1977). It is studied in rodent, dog and cell models, and in a few older human studies.
Does DSIP actually induce delta sleep?
The name comes from the EEG assay used to isolate it, not from a settled mechanism. The first group reported stronger delta and spindle patterns in rabbits. An outside group found no significant change in sleep or delta power in rats (Tobler and Borbely, 1980). Two small controlled studies looked at people with insomnia. Both reported weak or clinically unimportant differences (Monti et al., 1987; Bes et al., 1992). An anesthesia study reported reduced delta rhythm (Pomfrett et al., 2009). The 2006 review leaves the question open (Kovalzon and Strekalova, 2006).
Is there a known DSIP receptor?
No DSIP gene, precursor protein or receptor has been found in the indexed literature. That is why reviews call the peptide's natural occurrence and mechanism unresolved (Kovalzon and Strekalova, 2006).
Why do older papers report DSIP in so many tissues?
Most of that work measured DSIP-like immunoreactivity, not the peptide itself. One of the larger immunoreactive species was isolated and sequenced. It turned out to be an unrelated 77-residue peptide that the antiserum also recognizes (Sillard et al., 1993).
How should DSIP powder be stored?
Keep the lyophilized powder at -20°C and protected from light. After reconstitution, store the solution at 2 to 8°C, protected from light. Avoid freeze/thaw cycles. These are the conditions listed on the product page.
Where can researchers buy DSIP?
Disguised Alpha sells it for laboratory research. It is third-party tested, with the certificate published on the product page: DSIP (10MG).
Related compounds and guides
- Pinealon: a short pineal-derived tripeptide studied in overlapping Russian-language papers.
- Epitalon: the pineal tetrapeptide Ala-Glu-Asp-Gly.
- Pinealon research guide
- Epitalon research guide
- Semax research guide
- COA portal: every published certificate, by lot.
This product is for research use only. It has not been evaluated for safety or effectiveness in humans. Not for human consumption. All products are intended for laboratory research purposes only.