DSIP: The Complete Guide
The sleep peptide that has been studied for nearly fifty years and still has no known receptor. Here is what DSIP actually is, what the human trials found, and where it stands today.
This guide summarizes the published research and regulatory history of Delta Sleep-Inducing Peptide (DSIP). It is educational only and not a substitute for advice from a qualified healthcare professional. Sources are listed at the end.
Read this before the rest of the page
Persistent poor sleep is a symptom, not a diagnosis. Sleep apnea, thyroid disease, depression, anxiety disorders, restless legs and medication side effects all present as "I can't sleep" — and none of them respond to a peptide. Sleep apnea in particular is common, frequently undiagnosed, and carries real cardiovascular risk. If your sleep has been bad for more than a few weeks, if you snore heavily, or if you wake unrefreshed no matter how long you spend in bed, the correct first step is a proper evaluation, not a vial. Using any compound to paper over an untreated sleep disorder delays the diagnosis that would actually help you.
Most peptide guides open by telling you what a compound does. This one has to start somewhere stranger, because DSIP is genuinely unusual: it is one of the most-discussed sleep compounds in the peptide world, and almost everything about how it works is still unsettled. Nearly five decades after it was isolated, nobody has identified the gene that encodes it, the larger protein it is cut from, or the receptor it binds to.
That does not mean nothing is known. There is a real body of research here — animal work going back to the 1970s, a handful of small human trials in the 1980s and early 1990s, and a slow trickle of newer work on stress and neuroprotection. Some of it is genuinely interesting. Some of it is weaker than the internet suggests. This page walks through both.
If what you actually want to understand is why deep sleep matters and what sleep architecture is, our companion page on DSIP and sleep quality covers that ground in detail. This guide is about the compound itself.
What DSIP Is
Delta Sleep-Inducing Peptide is a nonapeptide — a chain of just nine amino acids — with a molecular weight of about 848.8 daltons. It is a simple linear molecule with no disulfide bonds and no unusual chemical modifications, which is part of why it breaks down so quickly in blood.
The discovery story is the reason for the name. In the 1970s, a group in Basel led by Marcel Monnier and G. A. Schoenenberger used low-frequency electrical stimulation of a specific thalamic region to induce sleep in rabbits, collected the blood draining from the animals' brains, and infused it into awake rabbits. The recipients showed the slow delta waves that define deep sleep. The team purified the fraction responsible and characterized it in 1977 as a nine-amino-acid peptide. They named it for the effect they had observed.
DSIP-like material has since been detected across the body, not just the brain: in the hypothalamus and pituitary, in the gastrointestinal tract, in plasma, and even in human breast milk. Levels in human plasma fluctuate over a 24-hour cycle. It also crosses the blood-brain barrier, which is unusual for a peptide and central to why it was considered a plausible drug candidate in the first place.
The unresolved part, stated plainly
A 2006 review in the Journal of Neurochemistry laid out the problem directly: no DSIP gene has been found, no precursor protein has been identified, and no specific DSIP receptor has been detected. The authors went further and raised the possibility that the 1977 sequencing — performed once, with the methods of the day, and never repeated using modern techniques — identified the wrong molecule, and that the real endogenous compound is something DSIP-like but not identical. They called it "a still unresolved riddle." That assessment has not been overturned.
How DSIP Works
Because there is no identified receptor, every mechanism below describes an observed effect rather than a confirmed pathway. Most of this work was done in rats, rabbits and cats, or in isolated tissue. Read it as a list of things DSIP has been shown to do in a laboratory, not as a settled explanation of how it produces any effect in a person.
Delta-Wave Enhancement
The original finding: both natural and synthetic DSIP increased delta-frequency EEG activity and sleep spindles in animals, with reported increases in cortical delta activity of roughly a third.
Stress-Axis Damping
In isolated rat pituitary tissue, DSIP blunted CRF-stimulated ACTH release — the first step of the cortisol cascade. This underpins the "stress-protective" framing DSIP is usually given.
Opioid-System Interaction
DSIP triggers release of met-enkephalin, one of the body's own opioid peptides, from brainstem tissue. Its sleep effects in some animal work were reversed by naloxone.
Somatostatin Inhibition
In rat median eminence tissue, DSIP suppressed release of somatostatin — the hormone that brakes growth hormone output — apparently through a dopamine-dependent route.
The pharmacokinetic puzzle
Here is the tension nobody has resolved. DSIP is cleared from blood in minutes — commonly reported around 7 to 15 minutes, with labelled peptide effectively gone within 15 to 20 minutes of an intravenous dose. Aminopeptidases clip off the N-terminal tryptophan and the molecule is inactivated. Yet the effects reported in both animal and human studies appear later than that and persist for hours.
Two explanations circulate. One is that circulating DSIP binds a protective carrier protein, or exists as part of a larger precursor, so measurements of the free peptide understate what is present. The other is that DSIP acts as a trigger — a brief signal setting off a longer downstream cascade. Neither has been demonstrated, and the open question is part of why pharmaceutical development stalled.
Simplified from the published pharmacokinetic and EEG literature. The gap between the two bars is the part of DSIP's biology that remains unexplained.
What the Human Trials Found
This is the section that matters most, and it is where DSIP pages tend to go soft. There are only a handful of human sleep studies, they are all small, they are all forty-plus years old, and they do not agree with each other.
The encouraging early results
The first human study, published in 1981, gave DSIP by slow intravenous infusion to six healthy volunteers in a double-blind crossover design. Participants reported an immediate sense of sleep pressure, and median total sleep time in the following 130 minutes rose by 59% compared with placebo. Six people is a very small study, but the effect was large and it was properly blinded.
Small open studies followed. In one, seven patients with severe insomnia received a course of ten injections; sleep was described as normalized in all but one, with improvements holding at follow-up three to seven months later. Daytime mood and performance were reported to improve as well. Open studies with no control group are the weakest kind of clinical evidence, but the reported durability is unusual and is part of why interest persisted.
The trial that cooled things off
In 1992, a Dutch group ran the most rigorous sleep study DSIP has: sixteen chronic insomnia patients, double-blind, matched pairs, parallel groups, with polysomnography rather than self-report. Half received 25 nmol/kg intravenously in the afternoon before three consecutive nights; half received a glucose placebo.
Sleep efficiency improved and sleep latency shortened on the objective measures. But the authors examined their own data and concluded the statistically significant effects were weak and could partly reflect an incidental shift in the placebo group. Subjective sleep quality did not change at all. Their conclusion was that short-term treatment of chronic insomnia with DSIP was unlikely to be of major therapeutic benefit.
Why the honest summary matters here
You will find pages describing DSIP as a clinically proven sleep aid. It is not. The best-controlled trial in the human literature found a weak signal and a negative overall verdict, and no company ever took the compound into modern development. What is fair to say is that DSIP shows measurable biological activity, that the early small studies were encouraging, and that the evidence base was never built out to the point where the question could be answered properly.
Beyond Sleep
Curiously, DSIP's strongest-looking human results are not about sleep at all.
Withdrawal syndromes
The reasoning came from animal work suggesting DSIP had activity at opioid receptors. In 1984, a Geneva group gave intravenous DSIP to 107 inpatients going through alcohol (47 patients) or opiate (60 patients) withdrawal. Among those evaluable, symptoms resolved or improved markedly and rapidly in 97% of the opiate group and 87% of the alcohol group. Anxiety was slower to settle than the physical symptoms. An earlier study in 67 patients reported a beneficial effect in 48 of 49 evaluable cases.
Those numbers look extraordinary, and they should be read with the study design in mind. Both were open-label with no placebo arm, outcomes were judged by clinical impression from physicians and nursing staff, a meaningful fraction of enrolled patients were not evaluable, and neither has been replicated in a modern randomized trial. Withdrawal symptoms also improve substantially with time, attention and supportive care alone — which is exactly what an uncontrolled design cannot separate out.
Pain and other areas
A companion 1984 paper reported benefit in patients with chronic, pronounced pain episodes, again in a small and uncontrolled setting. DSIP has also been examined in narcolepsy, and more recent work — largely from Russian groups — has looked at anticonvulsant activity in seizure models, antioxidant enzyme effects, and motor recovery after induced stroke in rats. All of that is preclinical or early, and none of it supports a claim about people.
The Growth Hormone Link
One thread deserves separating out, because it explains why DSIP comes up in conversations about growth hormone peptides. The body's largest natural GH pulse happens during deep slow-wave sleep. In rats, DSIP raised plasma growth hormone dose-dependently when injected into the brain's ventricles, and separately suppressed somatostatin — the hormone that brakes GH release. Both effects were blocked by a dopamine antagonist.
The most striking experiment came in 1988. Rats deprived of sleep for four hours showed the expected rebound in both slow-wave sleep and growth hormone afterwards. Injecting a highly specific antiserum against DSIP into the third ventricle blocked both rebounds. That is meaningful evidence that endogenous DSIP participates in linking deep sleep to the GH pulse.
Two caveats keep this from being a selling point. It is rat data, delivered directly into the brain. And it says something about DSIP's natural role in the body, not about what injecting extra DSIP under the skin does to a person's growth hormone. Anyone whose actual goal is growth hormone output is looking at the wrong compound — sermorelin, ipamorelin and tesamorelin have vastly more human data behind them.
Dosing in the Research
There is a large and rarely-mentioned gap between what the trials used and what circulates in community protocol literature. The table sets both out.
| Setting | Dose reported | Route | Notes |
|---|---|---|---|
| Healthy volunteers, 1981 (n=6) | 25 nmol/kg | Slow IV infusion | Median total sleep time up 59% over the following 130 min |
| Chronic insomnia, 1992 (n=16) | 25 nmol/kg | IV, afternoon before 3 nights | Weak objective signal; authors judged benefit unlikely |
| Withdrawal inpatients, 1984 (n=107) | 25 nmol/kg, repeated | Intravenous | Open-label; headache in a small number of patients |
| Animal studies | 25 mcg/kg IV; 0.1–1 mg/kg SC | IV and subcutaneous | Bell-shaped dose–response — higher doses were not better |
| Community protocol literature | 100–300 mcg per dose | Subcutaneous, evening | Not derived from any published trial |
Run the arithmetic on the trial dose and the gap becomes obvious. At a molecular weight of 848.8, 25 nmol/kg works out to roughly 21 mcg per kilogram — about 1.5 mg for a 70 kg adult. That is somewhere between five and fifteen times the 100–300 mcg figure quoted in most online protocols, and it was given intravenously rather than under the skin. The commonly circulated dose is not a scaled-down version of the research dose; it comes from a different lineage entirely.
The bell-shaped dose–response reported repeatedly in animal work is worth holding onto as well. Across several experimental setups, intermediate doses produced the effect and higher doses did not. That pattern is the opposite of the "if a little works, more will work better" instinct.
Schematic representation of the dose–response pattern described in the animal literature, not plotted from a single dataset.
Side Effects & Safety
The tolerability record in the published human studies is genuinely unremarkable, in the good sense. The 1981 volunteer study reported no psychological, physiological or biochemical adverse effects. The 67-patient withdrawal study reported no major side effects. The 107-patient study described tolerance as good aside from headache in a few patients.
What has been reported
- Headache — the most consistently mentioned effect across the clinical literature.
- Injection-site reactions — redness or minor irritation, as with any subcutaneous peptide.
- Grogginess or a heavy feeling — reported anecdotally when dosed close to waking rather than in the evening.
- A brief arousing effect before the sedating one — noted in some early EEG work, with sleep-promoting effects appearing later than expected.
What is not known
Almost everything about long-term use. The human exposure documented in the literature is measured in days to weeks, not months or years. There are no chronic dosing safety studies, no accumulation data, no drug-interaction studies, and no data in pregnancy or breastfeeding. The absence of reported harm in short studies is not the same as an established safety profile, and this is a compound where the honest phrase is "we don't know."
Situations that warrant real caution
Combining with sedatives. Benzodiazepines, Z-drugs such as zolpidem, prescription sleep medication, opioids and alcohol all act on sleep and arousal. No interaction studies exist. Do not combine without a clinician who knows what you are taking. Pregnancy and breastfeeding. No safety data — avoid. Diagnosed or suspected sleep disorders. See a sleep specialist, not a supplier. Competitive athletes. DSIP is not named individually on the WADA Prohibited List, but WADA's S0 category prohibits, at all times, any pharmacological substance with no current approval by a governmental health authority for human therapeutic use. DSIP fits that description. Treat it as prohibited and confirm with your national anti-doping organisation before going anywhere near it.
How DSIP Compares
DSIP sits in an odd position relative to the other compounds people consider for sleep. It is not a sedative, so it does not compete with sleeping pills on getting you unconscious. Its evidence base is thinner than almost anything else in this table.
| Compound | What it targets | Strength of human evidence | Where it fits |
|---|---|---|---|
| DSIP | Delta-wave sleep depth; stress axis | A few small trials, 1981–1992, mixed results | Sleep depth, for people who understand the evidence is unsettled |
| Melatonin | Sleep timing, not sleep depth | Large and well replicated | Jet lag and shifted schedules — a different problem |
| Selank | Anxiety and stress, daytime | Mostly small Russian trials | When racing thoughts are what keeps you awake |
| GH peptides | Growth hormone pulse tied to deep sleep | Substantial for GH; sleep effects secondary | GH goals first, sleep as a knock-on |
| Sleep fundamentals | Everything above, indirectly | Strongest evidence of anything listed | Always first, and not optional |
That last row is not filler. Consistent sleep and wake times, a cool dark room, morning daylight, caffeine cut off early and no alcohol near bedtime — alcohol is one of the most reliable suppressors of deep sleep there is — will outperform any peptide on this list, and cognitive behavioural therapy for insomnia has a stronger evidence base for chronic insomnia than anything discussed on this page. If you have not done those things, doing them is a better use of your money.
Where DSIP Stands Legally
DSIP's regulatory situation changed recently, and most pages online have not caught up. The international non-proprietary name for the compound is emideltide, which is the name regulators use.
- 2023 — the FDA placed emideltide, along with a group of other peptides, in Category 2 of its 503A bulk drug substances list, the designation for substances with identified potential safety risks. Compounding pharmacies could not prepare it.
- April 2026 — the FDA removed twelve substances, emideltide among them, from Category 2 for further evaluation, and scheduled an advisory committee review.
- July 2026 — the Pharmacy Compounding Advisory Committee reviewed seven peptides across two days. Six were recommended for the 503A Bulks List. Emideltide was the only one rejected, by a single vote, and it was the only compound where the committee agreed with the FDA's own scientists.
Two things follow. First, that vote is advisory and non-binding, and it changes nothing about what is legal today — a favourable vote would not have made any of these compounds legal to compound either, since that requires a separate rulemaking process. Second, the reason emideltide was the odd one out is worth noticing: unlike most of the peptides reviewed alongside it, DSIP has actually been tested in randomized double-blind human trials. Those trials found little. Compounds with no trials had nothing to fail.
In Costa Rica, as in the United States and the EU, DSIP is not approved as a finished pharmaceutical drug by any regulator. It is sold as a research compound. Our research peptides versus pharmaceutical peptides guide explains what that distinction actually means for quality, labelling and oversight.
Common Questions
Does DSIP actually work?
The honest answer is that it has not been established either way. Small early studies were positive, the one well-controlled trial found a weak effect and concluded it was unlikely to be of major therapeutic benefit, and no adequately powered modern trial has ever been run. Anyone stating flatly that it works, or that it doesn't, is going beyond what the evidence supports.
Is DSIP a sedative?
No. It does not act on the GABA-A receptors that sleeping pills target, and it does not produce the knocked-out feeling those drugs do. Research describes it as influencing sleep structure rather than forcing unconsciousness. That is also why people expecting a sleeping-pill effect are frequently disappointed by it.
How is DSIP different from melatonin?
They address different problems. Melatonin is a timing signal — it tells your body when the night is, which is why it helps with jet lag and shift work. DSIP has been studied for the depth and structure of sleep once you are already asleep. If your problem is that you fall asleep at the wrong time, melatonin is the better-matched tool and has far more evidence behind it.
Is DSIP addictive?
Nothing in the published research shows the dependence, tolerance or rebound insomnia associated with benzodiazepines and Z-drugs. But the studied exposure is short, so the accurate framing is "no dependence signal in a small body of short-term research" rather than a guarantee.
When would DSIP have been taken in the studies?
Both of the controlled human sleep studies used intravenous dosing well before sleep — the 1992 trial dosed in the afternoon, ahead of that night. Community protocols generally describe evening subcutaneous dosing instead. Given the very short plasma half-life, the timing question genuinely is not settled, and the research and the protocols disagree.
Can DSIP be combined with other peptides?
There is no research on DSIP combinations in humans. The pairing people ask about most is DSIP with a growth hormone peptide, on the logic that both relate to the deep-sleep GH pulse. That is a plausible-sounding idea, not a validated protocol, and no study has tested it. If you are considering any combination, establish your response to one compound at a time and involve a healthcare professional.
How should DSIP be stored?
Lyophilized vials keep refrigerated at 2–8°C, with freezing suitable for longer-term storage. Once reconstituted, the solution stays refrigerated and is used within a short window. DSIP is a small linear peptide with no stabilising disulfide bonds, so it is less forgiving of temperature swings than sturdier compounds — which matters more in Costa Rica's climate than elsewhere. See our guides on reconstitution and storing peptides in tropical climates.
What vial sizes does Peptides Costa Rica carry, and what does DSIP cost?
DSIP is listed in 5 mg, 10 mg and 15 mg vials, though availability varies. Current pricing and stock are on the DSIP product page, and five or more vials of the same product carry an automatic 15% discount. If a size is showing out of stock, message us and we will tell you when it is back rather than guess.
Is DSIP legal in Costa Rica?
It is sold here as a research compound, the same framework used in most countries with an active peptide market. It is not approved as a finished pharmaceutical drug by Costa Rica's Ministerio de Salud, the FDA or the EMA. Our FAQ page covers how ordering and delivery work within Costa Rica.
I have tried everything and still cannot sleep. Is DSIP the answer?
Probably not, and this is the most important question on the page. Chronic insomnia that resists sleep hygiene usually has a driver — apnea, an anxiety or mood disorder, a medication, a thyroid or pain problem, or a conditioned arousal pattern that responds specifically to cognitive behavioural therapy for insomnia. A compound whose best trial concluded it was unlikely to help chronic insomnia is not a sensible next step ahead of finding out what is actually going on. Please see a doctor or sleep specialist first.
Questions about DSIP?
We would rather explain the research honestly than sell you something that does not fit. Ask us what the evidence supports, what it doesn't, and whether this is the right compound for what you are trying to do — no pressure, no upsell.
Contact Us on WhatsAppImportant disclaimer: The information in this guide is general educational content only. It is not medical advice, a prescription, or a personalized recommendation. DSIP — international non-proprietary name emideltide — is not approved by the FDA, the EMA, or Costa Rica's Ministerio de Salud as a finished pharmaceutical drug for human use, and is sold as a research compound intended for laboratory and scientific study. In July 2026 the FDA's Pharmacy Compounding Advisory Committee voted against recommending emideltide for the 503A Bulks List; that vote is advisory and does not change the compound's legal status. It is not a treatment for insomnia, narcolepsy, withdrawal syndromes, pain, or any other condition. The human evidence base is small and dated: the best-controlled trial concluded that short-term treatment of chronic insomnia with DSIP was unlikely to be of major therapeutic benefit, and the mechanistic work described here is largely from animal models and isolated tissue. Dosing ranges discussed reflect what is reported in published research and community use; they are not endorsements of those doses for any specific individual. No data exist on long-term use, on use in pregnancy or breastfeeding, or on interactions with prescription sedatives, sleep medications, opioids or alcohol. DSIP falls within WADA's S0 non-approved substances category and should be treated as prohibited in tested sport. Persistent sleep problems can signal an underlying disorder that requires diagnosis — always consult a qualified healthcare professional before beginning any peptide protocol. Products sold by Peptides Costa Rica are intended for laboratory and research purposes only.
- Journal of Neurochemistry (Kovalzon & Strekalova, 2006): Review concluding that the DSIP gene, precursor protein and receptor all remain unidentified, and that the sleep-factor hypothesis is weakly documented.
- Neuropsychobiology (Bes et al., 1992): Double-blind polysomnographic trial in sixteen chronic insomnia patients; weak objective effects and a conclusion against major therapeutic benefit.
- International Journal of Clinical Pharmacology, Therapy and Toxicology (Schneider-Helmert et al., 1981): First human application, six volunteers, double-blind crossover; median total sleep time increased by 59% in the following interval.
- European Neurology (Dick et al., 1984): Open-label intravenous DSIP in 107 inpatients with alcohol or opiate withdrawal; symptom resolution in most evaluable patients, headache the main reported effect.
- European Neurology (Kaeser, 1984): Open study of ten injections in seven patients with severe insomnia, with follow-up over three to seven months.
- Proceedings of the National Academy of Sciences (Iyer, Marks, Kastin & McCann, 1988): Antiserum to DSIP injected into the rat third ventricle blocked both the slow-wave sleep and growth hormone rebound following sleep deprivation.
- Peptides and Neuroendocrinology (Iyer & McCann, 1987): DSIP stimulated growth hormone release and inhibited somatostatin release in rats, both blocked by a dopamine antagonist.
- Neuroscience & Biobehavioral Reviews (Schoenenberger, 1984): Review of the isolation and characterization of DSIP, including the U-shaped dose–response relationship.
- U.S. Food and Drug Administration: 503A bulk drug substances list and the July 2026 Pharmacy Compounding Advisory Committee proceedings on emideltide.
- World Anti-Doping Agency: Prohibited List, section S0, covering pharmacological substances without approval by any governmental health authority.
