DSIP
Named for deep sleep, with human trials that never settled whether it delivers
DSIP is a nine-amino-acid peptide isolated from rabbit brain blood in 1977 and named for delta-wave sleep. Unusually for a research peptide, it was tested in people: small insomnia trials in the 1980s and 1990s gave mixed results, and hormone studies found no effect. In July 2026 FDA's advisers voted against making it compoundable.
What is it?
DSIP, delta sleep-inducing peptide, is a nine-amino-acid peptide: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu. A group in Basel isolated it in 1977 from the cerebral venous blood of rabbits and named it for its apparent ability to promote the deep, delta-wave phase of sleep. It also goes by emideltide, the name FDA uses. Decades on, no gene, precursor protein or receptor for it has been found, which is why a 2006 review called it a still unresolved riddle.
It was tested in people more than most peptides sold today, mostly in insomnia, in small double-blind studies in the 1980s and early 1990s. The results pointed in different directions. The first volunteer study found 59% more sleep in the hours after an infusion, and a 1987 study in 14 severe insomniacs reported normalised sleep and better daytime alertness. But two other controlled studies found effects so weak that their authors judged them of little or no clinical value.
Tests of how it might work came back largely negative in humans. Infused DSIP did not change ACTH or cortisol, even under stimulation, and did not change growth hormone or prolactin. Under anaesthesia it did the opposite of what its name suggests, reducing EEG delta activity and lightening anaesthetic depth. In cats it reduced sleep. The most recent animal study found faster motor recovery after stroke in rats, a separate question from sleep.
The US decision is the clearest of any peptide on this site. On July 24, 2026 the Pharmacy Compounding Advisory Committee voted 6–7, with one abstention, against adding DSIP to the 503A bulks list: the only one of the seven peptides it reviewed that month to be rejected. Pharmacies could not compound it before the vote and cannot now (as of September 26, 2026).
Mechanism of Action
DSIP's mechanism is the weakest part of its story. Without a known gene or receptor, the proposed actions rest on indirect experiments, and several have been tested directly in people and failed. The four areas below are what the carded studies actually examined.
Sleep and EEG
In healthy volunteers, a morning infusion produced sleep pressure and 59% more sleep over the following hours without classic sedation. In insomnia the effects ranged from substantial to negligible. Under anaesthesia, DSIP reduced EEG delta rhythm rather than increasing it, and in cats it increased wakefulness. Whatever DSIP does to sleep, it is not a reliable delta-wave inducer.
Stress hormones
DSIP was once proposed as an inhibitor of corticotropin release. In healthy men, intravenous doses totalling 3 to 4 mg left ACTH and cortisol responses to CRH, and the normal midday surge, unchanged. The authors concluded that their data do not support an inhibitory role on the stress-hormone axis in humans.
Growth hormone and prolactin
In eight healthy women, DSIP at 25 µg/kg did not change growth hormone or prolactin at rest, did not blunt their response to arginine, and did not shift their overnight rhythm. Claims that DSIP works through growth hormone find no support in this human study.
Heart and brain after injury
In anaesthetised patients DSIP raised heart rate and reduced heart-rate variability, which the authors read as lower parasympathetic tone. In rats with an induced stroke, intranasal DSIP sped motor recovery without significantly shrinking the infarct. These are the most recent human and animal data, and neither is about sleep.
Published Research
About 50 papers in our evidence set concern DSIP, most from the 1980s and 1990s, and unusually for a research peptide many are human studies. Two often-cited clinical papers, a 1981 Lancet report in insomnia and a 1998 opioid-detoxification trial, have no abstract on PubMed and are not carded, because a card must describe what the abstract reports. The ten cards below put the positive and negative trials side by side.
First human study: sleep pressure within hours
Six healthy volunteers received a slow intravenous infusion of synthetic DSIP (25 nmol/kg) in the morning, in a double-blind crossover design. They reported sleep pressure at once, and total sleep rose 59% (median) over the next 130 minutes compared with placebo. The following night brought faster sleep onset and better sleep efficiency. EEG analysis found no classic sedation, and no side effects were observed.
Severe insomnia: the strongest positive result
In 14 middle-aged people with chronic insomnia, seven nights of DSIP substantially improved night sleep, with effects persisting into the first placebo night and daytime alertness and performance improving.
Chronic insomnia: weak effects, 'not likely' to help
Sixteen chronic insomniacs slept five nights in a laboratory; before the last three, half received 25 nmol/kg DSIP intravenously in the afternoon and half a glucose placebo, double-blind. Sleep efficiency was higher and sleep latency shorter with DSIP, but the authors judged these effects weak and partly due to a chance change in the placebo group. Subjective sleep did not improve, and they concluded short-term DSIP is not likely to be of major benefit.
Insomnia crossover: 'little clinical significance'
Insomniac patients received 25 nmol/kg DSIP or placebo intravenously over four nights in a double-blind crossover study with sleep recordings. Awakenings and waking time fell under DSIP, but not significantly versus baseline or placebo nights. Total and NREM sleep rose through light stage 2 sleep, deep and REM sleep did not change, and the NREM difference already existed at baseline. The authors called the improvement of little clinical significance.
No effect on the stress-hormone axis
Earlier work had suggested DSIP inhibits corticotropin release. In healthy young men given CRH (five per condition), intravenous DSIP (3 or 4 mg in total) left ACTH and cortisol responses almost identical to placebo, and in another ten men 4 mg of DSIP did not change the midday meal-related surge of either hormone. The authors conclude their data do not support an inhibitory role of DSIP on ACTH and cortisol in humans.
No effect on growth hormone or prolactin
In eight healthy women aged 17 to 36, DSIP at 25 µg/kg intravenously had no effect on growth hormone or prolactin, whether given alone, alongside arginine to stimulate growth hormone, or as an evening infusion studied across the night. The circadian rhythms of both hormones were unchanged. It directly tests whether DSIP moves growth hormone in people, and the answer here was no.
Under anaesthesia: lighter, not deeper
Twenty-four women having surgery were randomised to saline (12) or intravenous DSIP at 25, 50 or 100 nmol/kg (12), given while awake and again under propofol and isoflurane anaesthesia. The hypothesis was that DSIP would deepen anaesthesia. Instead it raised heart rate, lowered heart-rate variability and, paradoxically, reduced EEG delta rhythm and lightened anaesthesia on the bispectral index at 25 nmol/kg.
'A still unresolved riddle'
DSIP was isolated from rabbit cerebral venous blood in Basel in 1977 as a candidate sleep factor. This review notes that its link to sleep was never further characterised, partly because no DSIP gene, protein or receptor has been isolated, and calls the sleep-factor hypothesis extremely poorly documented. It proposes that related, still-unidentified peptides may explain the DSIP-like activity measured in tissues.
Stroke in rats: faster motor recovery
Rats received intranasal DSIP at 120 µg/kg about an hour before an induced stroke (middle cerebral artery occlusion) and daily for seven days after. Infarcts were smaller than in vehicle-treated rats, but not significantly. Motor performance on the rotarod recovered significantly faster with DSIP over 21 days of testing. It is one of the few recent DSIP studies, and it is about stroke rather than sleep.
In cats, less sleep
Cats given 30 nmol/kg DSIP by intraperitoneal injection slept less over the next 10 hours than after saline, losing light slow-wave sleep and REM sleep, with REM onset delayed. The authors suggest DSIP increased wakefulness in these animals and has a specific REM-reducing effect: the opposite of what its name promises, and one reason its sleep role is described as unresolved.
What people say, and what was measured
DSIP is named for what it was hoped to do. It was given to people repeatedly in the 1980s and 1990s, in placebo-controlled sleep studies, and the authors of those studies concluded it was not useful. That is unusually clear evidence for a peptide in this market, and it is negative.
It induces deep sleep — the name says so.
Heard in: Journal of Neurochemistry, Delta sleep-inducing peptide (DSIP): a still unresolved riddle, which reviews the gap between the name and the evidence (read October 1, 2026). Source
The review's own position is that DSIP itself is doubtful as a sleep factor: it notes that certain artificial structural analogues promoted slow-wave sleep in rabbits and rats while DSIP itself did not, and that its distribution does not match a sleep role. PMID: 16539679
Tested in people; not shownIt is an effective treatment for insomnia.
Heard in: Grey Peptides listing review, October 1, 2026: listings sell it for insomnia and sleep quality. Sellers are not named.
Two double-blind studies tested exactly that and both authors said no. In chronic insomniacs, sleep efficiency and latency improved against placebo but the effects were weak and partly attributable to a change in the placebo group, nothing else changed, and the authors concluded short-term DSIP is unlikely to be of major benefit. A separate short-term study found the sleep improvement of little clinical significance. PMID: 1299794, 3583493
Tested in people; not shownIt works without sedation, so it is safer than sleeping pills.
Heard in: Grey Peptides listing review, October 1, 2026: listings contrast it with hypnotics. Sellers are not named.
The no-sedation part is a real finding from the 1981 study: delayed effects on the following night included shorter sleep onset and better sleep efficiency, and the analyses revealed no sedation in the classic pharmacological way, with no side effects observed. What it does not establish is a benefit worth having. PMID: 6895513
Tested in people; mixedIt balances hormones and the stress axis.
Heard in: Grey Peptides listing review, October 1, 2026: listings mention hormonal and stress-axis effects. Sellers are not named.
Measured, and absent. DSIP did not affect CRH- and meal-induced ACTH and cortisol secretion in people, and a separate study found it did not influence growth hormone or prolactin. PMID: 7777652, 8475226
Tested in people; not shownEach claim is quoted from where it is said, never from a seller, and checked as of October 1, 2026 against the studies listed below.
Dosing Data
The human studies used intravenous infusions, most often 25 nmol/kg, which is about 21 µg/kg or roughly 1.5 mg for a 70 kg adult, given as single infusions at different times of day; the hormone studies used total doses of 3 to 4 mg. The community figure in our dataset, 100–500 µg injected under the skin at bedtime, is smaller and uses a route none of the carded human trials tested.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
→ Full DSIP dosage guide — what the 1980s trials infused, and why the community bedtime injection is a different thing
Side Effects & Contraindications
Reported Side Effects
The first human study reported that DSIP was well tolerated, with no psychological, physiological or biochemical side effects in six volunteers. The other abstracts give no adverse-event tables, and one found effects on the heart that matter more than the sleep results.
Contraindications & Cautions
These cautions come from the carded studies rather than from a systematic safety record, which DSIP never acquired.
Legal Status
DSIP is not approved as a medicine in any of the jurisdictions below, and in the US it is the one peptide FDA's advisory committee rejected in July 2026. Status as of September 26, 2026.
Frequently Asked Questions
?Does DSIP actually induce deep sleep?
Not reliably. A first study in six volunteers found 59% more sleep after an infusion, and one 1987 insomnia study reported normalised sleep. But two other controlled insomnia studies judged the effects weak or of little clinical significance, and under anaesthesia DSIP reduced EEG delta activity rather than increasing it.
?Is DSIP made by the body?
That is still uncertain. It was isolated from rabbit brain blood in 1977, but no gene, precursor protein or receptor for it has been identified, and a 2006 review suggested that related, still-unknown peptides may account for the DSIP-like activity measured in tissues.
?Does DSIP raise growth hormone or lower cortisol?
Not in the human studies that tested it. Intravenous DSIP did not change growth hormone or prolactin in healthy women, and did not change ACTH or cortisol, at rest or under stimulation, in healthy men.
?Is DSIP safe?
The first volunteer study reported no side effects, but that was six people and a single dose. In anaesthetised patients DSIP raised heart rate and lowered heart-rate variability. There are no modern safety data for repeated use, and research-grade vials are unregulated.
?Can a US pharmacy compound DSIP?
No. On July 24, 2026 the Pharmacy Compounding Advisory Committee voted 6–7 against adding it to the 503A bulks list, the only rejection among the seven peptides it reviewed that month. It is on no list that allows compounding.
?Why is DSIP also called emideltide?
Emideltide is the name FDA uses for DSIP in its compounding lists, including the Category 2 page, where its nomination appears among those withdrawn. The two names refer to the same nine-amino-acid peptide.
References
- [pubmed] Schneider-Helmert D, et al. "Acute and delayed effects of DSIP (delta sleep-inducing peptide) on human sleep behavior." Int J Clin Pharmacol Ther Toxicol, 1981;19(8):341-5. PMID: 6895513.
- [pubmed] Schneider-Helmert D. "Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia." Eur Neurol, 1987;27(2):120-9. PMID: 3622582.
- [pubmed] Bes F, et al. "Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study." Neuropsychobiology, 1992;26(4):193-7. PMID: 1299794.
- [pubmed] 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;7(2):105-10. PMID: 3583493.
- [pubmed] Späth-Schwalbe E, et al. "Delta-sleep-inducing peptide does not affect CRH and meal-induced ACTH and cortisol secretion." Psychoneuroendocrinology, 1995;20(3):231-7. PMID: 7777652.
- [pubmed] Giusti M, et al. "Delta sleep-inducing peptide administration does not influence growth hormone and prolactin secretion in normal women." Psychoneuroendocrinology, 1993;18(1):79-84. PMID: 8475226.
- [pubmed] 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;26(2):128-34. PMID: 19142086.
- [pubmed] Kovalzon VM, et al. "Delta sleep-inducing peptide (DSIP): a still unresolved riddle." J Neurochem, 2006;97(2):303-9. PMID: 16539679.
- [pubmed] Tukhovskaya EA, et al. "Delta Sleep-Inducing Peptide Recovers Motor Function in SD Rats after Focal Stroke." Molecules, 2021;26(17). PMID: 34500605.
- [pubmed] Sommerfelt L. "Reduced sleep in cats after intraperitoneal injection of delta-sleep-inducing peptide (DSIP)." Neurosci Lett, 1985;58(1):73-7. PMID: 3840239.
- [pubmed] Sudakov KV, et al. "Delta sleep-inducing peptide and nootropic drugs eliminate electroencephalographic and autonomic signs of emotional stress." Neurosci Behav Physiol, 1995;25:403-410.
Sources & Citations
Every citation on this page is PubMed-indexed and has been checked against its record. Two frequently cited DSIP clinical papers have no abstract on PubMed and are not carded, because every card here describes what its abstract reports. Grey Peptides sells nothing and links to no vendor.
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