DSIP (delta sleep-inducing peptide) is a 9-amino-acid peptide that Swiss scientists isolated in 1977 from the blood of rabbits in deep sleep. It is studied as a regulator of sleep and the stress response. Study results are inconsistent, however, and even after almost 50 years neither its gene nor the receptor it acts through is known.[5]
DSIP at a glance
- Sequence: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE), molecular weight about 849 g/mol.
- Discovery: 1977, Schoenenberger and Monnier, Basel.[1]
- Areas studied: deep sleep, the stress axis and cortisol, withdrawal symptoms.
- The mystery: its own gene and receptor have not yet been found.
How was DSIP discovered?
A Swiss team in Basel electrically stimulated the sleep-inducing area of the brain in rabbits and then prepared a filtrate from their blood. When they introduced it into the brain ventricles of awake rabbits, the animals fell asleep with a predominance of slow delta waves on the EEG. From the filtrate they gradually isolated the nonapeptide that caused this effect and named it after it.[1]
What is delta sleep and why does it matter?
Delta sleep, also called deep sleep or stage N3, is the deepest stage of sleep, with slow delta waves on the EEG. It is most abundant in the first half of the night. During this stage growth hormone release peaks, cortisol levels fall and the brain processes information from the previous day. Delta sleep naturally declines with age.
What have studies shown about DSIP and sleep?
The discovery was followed by a wave of research. A 1984 review concluded that effects on sleep had been confirmed in a number of studies but were often weak and depended on the dose, the time of day it was given and the animal species. In some studies DSIP promoted sleep; in others it had no effect at all.[2]
Small studies were carried out in humans, mostly in the 1980s. Swiss authors described improved sleep in patients with insomnia and some other effects – for example, better coping with stress. The studies were small, however, and their results could not be reliably reproduced.[3]
How is DSIP related to stress and cortisol?
Its effect on the stress axis gradually proved more interesting than its effect on sleep. In studies, DSIP reduced the release of ACTH – the hormone that triggers cortisol production – and dampened the stress response in animals. Protection of cells during oxygen deprivation was also described.[2]
For the same reason, DSIP was studied for withdrawal symptoms during alcohol and opiate withdrawal. A small clinical study described an easing of symptoms in some patients.[4]
| Area | Model | What was observed |
|---|---|---|
| Sleep | Rabbits | Induction of sleep with delta waves[1] |
| Sleep | Various animals | Inconsistent results depending on dose and timing[2] |
| Insomnia, stress | Small studies in humans | Improvement in some patients[3] |
| Withdrawal | Patients (alcohol, opiates) | Easing of symptoms[4] |
Why is DSIP still a mystery?
A 2006 review bears the telling title “a still unresolved riddle”. Scientists have still not found a gene that would encode DSIP, nor a specific receptor it binds to. It is not even clear how the peptide crosses the blood–brain barrier from the blood and how quickly it breaks down.[5] DSIP may be a fragment of a larger protein, or its effects may be mediated by a similar molecule.
Is DSIP safe?
In small studies in humans DSIP was well tolerated; headache, temporary drowsiness or vivid dreams were described. There are no modern safety studies, however, and DSIP is not an approved medicine anywhere.
How does DSIP differ from melatonin?
Melatonin is a hormone that controls the timing of sleep – it signals to the body that it is night. Its mechanism is well known and it is available as a dietary supplement and a medicine. DSIP is associated more with the depth of sleep and the stress response, and its mechanism remains unknown. In stress research it is sometimes studied alongside the peptide Selank.
Why is DSIP so hard to study?
DSIP is quickly broken down by enzymes in the blood, so its level falls within minutes of administration. It is also hard to measure reliably – different laboratories have reported very different concentrations in the blood and brain. Add to that the fact that sleep itself is influenced by many factors: time of day, stress, the laboratory environment. Small studies with such variable results can easily reach contradictory conclusions.[5]
How is sleep measured in studies?
The standard is polysomnography – an overnight recording of brain activity (EEG), eye movements, muscle tone, breathing and heart activity. From it, the individual sleep stages, their duration and the number of awakenings are determined. Delta sleep is recognised by slow, high-amplitude waves. Older DSIP studies often used only questionnaires or short recordings, which is one reason their results are hard to compare.
Does DSIP affect hormones?
Besides the stress axis, review papers have described effects of DSIP on the release of other pituitary hormones, such as luteinising hormone and growth hormone, and on body temperature. The results differed between studies, however, and were often single experiments in animals.[2] The 2006 review therefore describes DSIP more as a modulator that fine-tunes several systems at once than as a substance with one clear effect.[5]
How has DSIP research developed?
| Period | Event |
|---|---|
| 1977 | Isolation from the blood of sleeping rabbits in Basel[1] |
| 1980s | Studies in people with insomnia and withdrawal symptoms[3][4] |
| 1984 | Review: inconsistent effects on sleep[2] |
| 2006 | Review “a still unresolved riddle”[5] |
Summary
- DSIP is a nonapeptide isolated in 1977 from the blood of rabbits in deep sleep.[1]
- Studies of its effect on sleep produced inconsistent results.[2]
- Its effect on the stress axis, cortisol and withdrawal symptoms proved more interesting.[3][4]
- Neither its gene nor its receptor has yet been found, which is why it remains a scientific mystery.[5]
- DSIP is not an approved medicine in any EU country.
Frequently asked questions
Is DSIP a sleeping pill?
No. Studies describe fine regulation of sleep and the stress response rather than directly putting you to sleep. The results were also inconsistent.
Does DSIP occur naturally in the body?
DSIP-like substances have been found in the blood, brain and some organs. However, a gene that would encode DSIP has not yet been found.
How long does DSIP act?
It breaks down in the blood within minutes. Some studies, however, described effects that lasted longer than its presence in the blood would suggest – that too is part of the DSIP mystery.
Is DSIP an approved medicine?
No. DSIP is not registered as a medicine in any EU country and is sold only as a research chemical.
Why is DSIP called “delta”?
After delta waves – the slow, high-amplitude brain waves that characterise the deepest stage of sleep on the EEG. It was their increase in rabbits after receiving a filtrate from the blood of sleeping animals that led to the whole peptide being named in 1977.[1]
How many amino acids does DSIP have?
Nine: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. That is why it is called a nonapeptide.
Why was DSIP studied for withdrawal symptoms?
Because of its effect on the stress axis and sleep, both of which are disrupted during withdrawal. A small clinical study from the 1980s described an easing of symptoms during alcohol and opiate withdrawal in some patients.[4]
For laboratory research we offer DSIP 5 mg in stock.
Sources
- Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram (-sleep)-inducing peptide. Proceedings of the National Academy of Sciences USA. 1977;74(3):1282–1286. PubMed ↗
- Graf MV, Kastin AJ. Delta-sleep-inducing peptide (DSIP): a review. Neuroscience & Biobehavioral Reviews. 1984;8(1):83–93. PubMed ↗
- Schneider-Helmert D, Schoenenberger GA. Effects of DSIP in man. Multifunctional psychophysiological properties besides induction of natural sleep. Neuropsychobiology. 1983. PubMed ↗
- Dick P, et al. DSIP in the treatment of withdrawal syndromes from alcohol and opiates. European Neurology. 1984. PubMed ↗
- Kovalzon VM, Strekalova TV. Delta sleep-inducing peptide (DSIP): a still unresolved riddle. Journal of Neurochemistry. 2006;97(2):303–309. PubMed ↗
The information in this article is for educational purposes only and does not replace medical advice. The substances described are not approved medicines, and Jolt Peptides products are intended solely for laboratory research, not for use in humans or animals.