Quick answer: DSIP, short for delta sleep-inducing peptide, was first isolated in the 1970s by Gilbert Schoenenberger and Marcel Monnier at the University of Basel in Switzerland. It is a small natural neuropeptide of nine amino acids. Its history is a good example of a molecule that was easy to name and harder to fully explain.
Who discovered DSIP, and where?
The work came out of Basel. Monnier had been studying since the 1960s whether blood could carry a factor linked to sleep. Together with Schoenenberger, he reported the isolation of a peptide in 1977, in a paper published in the Proceedings of the National Academy of Sciences.
The name describes the original assay. Delta waves are the slow brain-wave patterns recorded by EEG (electroencephalography) that are associated with deep sleep. The peptide was named for what the researchers saw in that recording.
How was DSIP isolated?
The researchers collected blood from the cerebral veins of rabbits in which a sleep-like state had been brought on by electrical stimulation of a region of the thalamus. They separated the blood into fractions and passed material through dialysis, a method that sorts molecules by size. Fractions were then given to recipient rabbits, and the EEG recordings were examined for more delta activity.
The active fraction was purified, and the group reported that it was a peptide of nine amino acids. A synthetic version was then made so that the structure could be tested directly. This step, confirming a natural molecule with a made copy, is what turned DSIP from a fraction in a dish into a defined compound that other laboratories could order and study. You may also see it written as delta-sleep inducing peptide or simply DSIP.
What did later laboratory research examine?
After 1977 the peptide was examined in cell studies and preclinical research well beyond sleep. Published work looked at:
- sleep and wake patterns in EEG recordings
- release of pituitary and other hormones
- stress-response models
- neurotransmitter and neuropeptide signaling
- body temperature regulation
This breadth is why our product page lists neuroendocrine and CNS pathway work next to sleep and circadian studies. It is also why the evidence is hard to summarize in one line. Reviews of the field have described results as inconsistent between laboratories, with some groups reporting effects and others not. Published work also describes DSIP as having a short half-life in plasma, because enzymes break it down quickly.
What is still unresolved about DSIP?
| Question | Where the research stands |
|---|---|
| Is the peptide found naturally? | Yes. It was first isolated from a biological source, and DSIP-like material has been reported in several tissues. |
| What is its precursor? | Not firmly established. A clear gene and parent protein have been hard to pin down. |
| What is its receptor? | No single, widely accepted receptor has been defined. |
| Is the sleep effect consistent? | Results varied across protocols, so the evidence is mixed. |
In short, the isolation and structure are well documented. The mechanism and the precise biological role remain open questions, and much of the work is early or limited.
What is in the DSIP 10mg vial?
Our DSIP 10mg vial contains the nine-amino-acid peptide as a lyophilized (freeze-dried) powder, listed at 10mg per vial and at 99% purity or higher by HPLC. A 5mg version is also listed as DSIP 5mg. It is sold for laboratory research use only.
How is DSIP verified?
A DSIP batch is checked three ways: mass spectrometry for identity, HPLC for purity, and a content figure for how much peptide is in the vial. The measured mass should match what a nine-residue peptide of this sequence is expected to give.
Two quality problems are worth knowing. DSIP contains a tryptophan residue, an amino acid that can oxidize and show up as an extra mass peak. Its glycine-rich sequence can also produce closely related synthesis by-products that sit near the main peak. A good report shows both mass and purity, not purity alone. Our guide to reading a peptide Certificate of Analysis covers each line, and our piece on why synthesis determines peptide quality explains where by-products come from.
Frequently asked questions
What is the amino acid sequence of DSIP?
The reported sequence is Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, nine amino acids in total. It is read from the N-terminus, which starts with tryptophan.
Is DSIP the same as melatonin?
No. Melatonin is a small molecule made by the pineal gland, while DSIP is a nine-residue peptide first isolated from blood. They are different compounds with different research histories.
Why is it called delta sleep-inducing peptide?
It was named after the delta EEG waves that the 1970s researchers observed. The name reflects the original assay, not a confirmed function.
What is the difference between the 5mg and 10mg DSIP vials?
Both contain the same compound. The difference is the amount of peptide per vial. For more on why sizes differ, see why the same peptide comes in different vial sizes.
Does the DSIP 10mg vial ship as a powder?
Yes, it ships as a lyophilized powder, as listed on the product page.
Is there a lot of published research on DSIP?
There is a body of work going back to the late 1970s, but it is mostly early laboratory research with mixed results. The mechanism and receptor are not settled.
Every lot we sell has a Certificate of Analysis you can read before you order. Questions before you buy? Our team is in Chandler, Arizona: (888) 745-1505 or our contact page.
View DSIP | 10mgAll products sold by BioPure Peptides are intended strictly for in-vitro laboratory and research use only. They are not for human or animal consumption. These statements have not been evaluated by the U.S. Food and Drug Administration, and these products are not intended to diagnose, treat, cure, or prevent any disease.