DSIP: The Peptide Named After an Effect Its Best Human Trial Could Not Find

Delta Sleep-Inducing Peptide carries its claim in its name, and the name comes from a 1977 rabbit experiment. Five decades on, the best-controlled human trial concluded that the improvement it produced was "of little clinical significance."

In July 2026 DSIP became the only peptide of seven that an FDA advisory committee declined to recommend, with reviewers citing a lack of both safety and efficacy data. This article goes to the primary literature to explain how a compound ends up with a mechanism in its name and almost nothing behind it. Identity details sit on the DSIP compound page, within the cognitive and neuroprotective peptides category.

Does DSIP improve sleep in humans?

Not on the evidence available. The most rigorous human study — Monti and colleagues (International Journal of Clinical Pharmacology Research, 1987), testing intravenous DSIP in chronic insomniacs — found effects on sleep latency and awakenings that were not statistically significant versus placebo, and the authors concluded that sleep improvement under DSIP treatment "is of little clinical significance." That is the compound's best-designed human test, and it is negative.

The standing review of the field, Graf and Kastin's "Delta-sleep-inducing peptide (DSIP): a review" (Neuroscience & Biobehavioral Reviews, 1984), catalogues both positive and null findings across sleep studies and documents replication problems that were already apparent in the early 1980s.

Four decades later, those problems have not been resolved. That is the unusual feature of this compound's file. The issue is not an empty literature awaiting its first study — it is a literature that was written, disagreed with itself, and then stopped.

Where did the name "delta sleep-inducing peptide" come from?

From rabbits, in 1977. The peptide was characterised by Guido Schoenenberger and Marcel Monnier's Swiss group and published in PNAS as "Characterization of a delta-electroencephalogram (-sleep)-inducing peptide". The observation itself was real: infusing the substance produced delta-wave EEG activity in rabbits. The compound was named for what it did to rabbit EEG traces, and every later claim inherited that name.

This is the mechanism by which a marketing asset gets built into a molecule's identity. A compound called "delta sleep-inducing peptide" arrives pre-loaded with a claim, and the claim is restated every time the name is written — including in articles that never assert it directly.

Nothing about the 1977 result was overstated by the people who produced it. A rabbit EEG finding was reported as a rabbit EEG finding. What followed is that the name outlived the evidence supporting it.

What is DSIP, and why do FDA documents call it emideltide?

DSIP is an endogenous nonapeptide — Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, or WAGGDASGE — found in the hypothalamus and cerebrospinal fluid, carrying CAS 62568-57-4, PubChem CID 68816 and a molecular weight of 848.8 g/mol. In FDA compounding documents it appears as emideltide, not as DSIP. That naming split has a practical consequence: searching the regulatory record for "DSIP" returns nothing at all, because the paperwork does not use the word.

Nine amino acids is short, and every residue in the sequence is a common one. That combination creates a specific verification problem covered further down: DSIP's composition overlaps other small neuropeptides, so mass is the only reliable way to know what is in a vial.

Does DSIP have a receptor, and has anyone studied it since the 1980s?

Two absences define this compound. No receptor for DSIP has ever been conclusively identified, which is unusual for a peptide carrying a named physiological effect — the name asserts a mechanism that has no molecular target attached to it. And DSIP has attracted essentially no modern controlled research: the evidence base is a 1970s–80s literature that was never revisited with contemporary methods, instrumentation or trial design.

Take those together and the shape of the problem is clear. A missing receptor is not by itself disqualifying — plenty of endogenous peptides were studied for years before their targets were found. What makes it load-bearing here is the second absence. There has been no sustained modern effort that might have located one.

The compound is therefore not so much unproven as unexamined-since. Its file was opened, worked on for roughly a decade, and left.

Why did the FDA advisory committee reject DSIP when it backed six other peptides?

Because reviewers found the safety and efficacy data insufficient. DSIP came off the FDA's 503A Category 2 list in the April 2026 reclassification, then went before the Pharmacy Compounding Advisory Committee on 23–24 July 2026 as emideltide, nominated for insomnia, narcolepsy and opioid use disorder. Of seven peptides reviewed across those two days, the committee recommended six. Emideltide was the only rejection, on a vote of 6 in favour, 7 against, 1 abstention.

That result deserves weight precisely because of what it sits next to. The same committee, on the same days, backed BPC-157, KPV, TB-500, MOTS-c, Semax and Epitalon — several of them over objections from FDA's own reviewers (STAT News, July 24, 2026). A panel willing to advance compounds on thin evidence still would not advance this one.

The vote is advisory. FDA has not completed rulemaking on any of the seven, so nothing has changed in law for the six that were recommended either. See our FDA peptide regulation timeline for the full sequence.

DSIP is not named on the WADA Prohibited List (2026 List, checked August 2026).

What dose of DSIP has actually been tested in humans?

The published intravenous trials dosed DSIP at roughly 25 nmol/kg — about 1.5 mg for a 70 kg adult, a figure we derived from the trial dose and the verified molecular weight rather than one quoted in the paper. Community subcutaneous convention runs to 200–500 mcg, roughly a third to a fifth of the trial exposure, by a different route. The protocol most people follow has never been tested.

The second half of that sentence matters as much as the first. The protocol that was tested did not produce a significant result anyway, so the community regimen is not a smaller version of something that worked — it is a smaller version, by another route, of something that did not.

There is no validated human dosing regimen for DSIP, and this article does not present one. The peptide dosing calculator and the reconstitution calculator convert a chosen dose into a syringe volume. They are arithmetic, not a recommendation, and no published source tells you which number to put into them.

Why do community reports on DSIP split so evenly?

Reports on peptide forums divide unusually evenly between people describing markedly deeper sleep within the first nights and a substantial group reporting nothing at all. That split is what the trial data predicts. Sleep is among the most placebo-responsive endpoints in medicine, subjective sleep quality correlates poorly with measured sleep architecture, and a compound with a genuinely inconsistent effect will produce exactly this pattern of testimony.

Neither group is lying. Both are reporting an experience accurately, and the evidence simply does not support treating either experience as generalisable to a third person.

This is also why the trial design in the final section specifies polysomnography. The one thing self-report cannot measure is the thing DSIP is named for. Discussion sits in the Peptigrity forum, where reports should be read as anecdote rather than data.

Which DSIP claims survive the evidence?

One DSIP claim is not merely unsupported but contradicted: reduced sleep onset latency, which showed no significant effect in the controlled intravenous trial. The headline delta-sleep claim is not established in humans, resting on rabbit EEG from 1977 and inconsistent human results. Cortisol effects are unreplicated, antioxidant and neuroprotective claims are animal and in vitro only, withdrawal use is unconfirmed, the mechanism is unknown, and safety data is insufficient.

How does DSIP compare with other sleep peptides?

DSIP is the only compound in the sleep-peptide group whose own controlled trial returned a null result, and the only one an FDA advisory committee has rejected. Against melatonin — the honest comparator, with a large evidence base and a modest effect on sleep onset — DSIP has one negative controlled trial and a name. Epithalon rests on single-institution data in elderly subjects and was recommended by the same July 2026 panel; Pinealon is preclinical only.

The three-way comparison across the research compounds is covered in peptides for sleep: DSIP, Epithalon and Pinealon.

How do you verify a DSIP vial before you buy it?

DSIP's short sequence is its specific sourcing risk. Nine amino acids, all common, means HPLC purity tells you almost nothing about identity — a vial can be 99% pure and contain a different small neuropeptide entirely. Mass spectrometry showing a mass near 848.8 Da is not one check among several for this compound; it is the whole test. The CAS number, net peptide content and an endotoxin result cover what mass cannot.

Method reading: mass spectrometry for peptides and how to read peptide lab test results. The compound-specific walkthrough is in where to buy DSIP.

Purity and quantity are separate axes, which is the subject of why 10 mg isn't 10 mg.

What does Peptigrity's platform data show for DSIP?

Peptigrity tracks 530 shops and 11,852 independent lab tests across 118 peptides, with 1,283 community reviews (verified August 2026). Trust scores weight community reviews and independently verified HPLC purity equally, at 50% each, with no financial relationship influencing the ranking. DSIP's per-compound purity index score, test count and contributing laboratory count are read live from the Purity Index rather than asserted here.

Independent results sit in the lab test database, and per-milligram offers with shops-in-stock, median and lowest price in DSIP price data. Those figures exclude shipping, taxes and customs, coupon codes, bulk tiers, multi-vial kits and account-gated pricing.

One caveat applies across the whole dataset: published certificates are the ones vendors chose to publish, which makes the sample selection-biased rather than a random market survey. For a nine-residue peptide the caveat has extra force, because a certificate reporting only HPLC purity does not establish that the vial contains DSIP at all.

Frequently Asked Questions

Does DSIP work for sleep?

The honest answer is that it has never been shown to, reliably. The best-controlled human trial found effects that were not statistically significant and concluded they were of little clinical significance. Some smaller and earlier studies reported benefit; the results have not replicated.

Why is it called delta sleep-inducing peptide if it may not induce sleep?

The name comes from a 1977 experiment in rabbits, where the substance produced delta-wave EEG activity. It describes an animal EEG observation, not a demonstrated human clinical effect.

What happened at the FDA meeting in July 2026?

DSIP — listed as emideltide — was the only one of seven peptides the advisory committee declined to recommend for compounding, on a 6–7–1 vote, citing insufficient safety and efficacy data for insomnia, narcolepsy and opioid use disorder.

Is DSIP banned in sport?

No. DSIP is not named on the WADA Prohibited List.

How do I know my vial is really DSIP?

Mass spectrometry showing a mass near 848.8 Da. With a nine-amino-acid peptide made of common residues, HPLC purity alone cannot establish identity.

Is DSIP safe?

Small studies reported good tolerability, but there is no substantial safety database, and FDA reviewers cited the absence of safety data as part of their 2026 rationale. Long-term human safety is unknown.

The trial that would settle this

The trial that would settle DSIP measures slow-wave sleep duration by polysomnography, because the compound's entire claim is about sleep architecture and sleep diaries cannot assess it. It is randomised, double-blind and placebo-controlled in a defined insomnia phenotype, and it doses subcutaneously — the route people actually use — with pharmacokinetic sampling, since the published trials are intravenous at roughly six times community doses.

Nobody is running it. DSIP has been studied for nearly fifty years without producing an answer, which is itself informative, and with the FDA panel's rejection removing the compounding pathway that would have created commercial interest, nobody is likely to.

Where this leaves DSIP

DSIP is a compound whose reputation rests almost entirely on its name. The underlying biology may still be real — an endogenous nonapeptide associated with sleep regulation is a reasonable object of study — but fifty years on the human evidence remains thin, inconsistent and old, and the most recent expert review of it was a rejection. The 1987 trial in chronic insomniacs is still the best test anyone has run on it.

If you are looking for a sleep intervention with an evidence base, DSIP is not currently it. If you are researching the compound itself, the honest framing is an unresolved question rather than a working tool. The gap between those two positions is exactly the width of the word "inducing" in its name.

Browse the cognitive and neuroprotective peptides category, or our complete peptide guide with 118 compounds (verified August 2026). For per-injection volume, use the peptide dosing calculator alongside the reconstitution calculator. Compare shops through independent lab tests and community-verified shop reviews.

This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.