DPDaily Peptide

DSIP · DECODED

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GREY MARKETNEUROPEPTIDE · ENDOGENOUS

DSIP

Decoded · Grey Market · Regulatory Gray Zone

Named for something it doesn't reliably do. Delta Sleep-Inducing Peptide was named in 1977 based on early animal studies suggesting it drove delta-wave sleep. The name stuck. The human evidence didn't follow. Modern controlled studies have not consistently replicated the effect, and the mechanism that was proposed (ACTH and cortisol suppression) did not hold up in human trials.

BY THE NUMBERS

9
AMINO ACIDS · NONAPEPTIDE
1977
YEAR FIRST ISOLATED BY MONNIER AND SCHOENENBERGER
0
IDENTIFIED GENE OR RECEPTOR FOR DSIP
0
FDA APPROVALS OR ACTIVE CLINICAL TRIALS

HOW IT WORKS

The proposed mechanism (modulation of ACTH and cortisol to promote delta-wave sleep) did not replicate in a controlled human study (PMID: 7777652). No gene or receptor for DSIP has been identified in the human genome. Whether it acts as a neurotransmitter, neuromodulator, or through non-specific pathways is not established. Mechanism of action in humans remains uncharacterized.

WHERE IT CAME FROM

Delta Sleep-Inducing Peptide (DSIP, also known by the INN name emideltide) is a nine-amino acid neuropeptide first isolated in 1977 by Marcel Monnier and Alex Schoenenberger at the University of Basel. They identified it in the cerebral venous blood of rabbits that had been put to sleep by electrical stimulation of the thalamus, and found that injecting the isolated factor into other rabbits increased the amount of time those animals spent in slow-wave sleep. The compound was named for that observation and has been called DSIP ever since.

The naming created a problem. Delta sleep-inducing peptide implies a reliably established mechanism of action in humans. The human evidence never justified that confidence. Research in the 1970s and 1980s produced a range of findings, some supporting sleep effects and others finding no effect or even opposite effects depending on the dose, timing, and population. The gene encoding DSIP has not been identified. The receptor has not been identified. The proposed mechanism involving ACTH and cortisol modulation, which would explain an anti-stress effect alongside the sleep effect, did not replicate in at least one controlled human trial (PMID 7777652). DSIP is endogenous (it can be detected in human blood and cerebrospinal fluid), but its physiological role remains unclear.

THE STUDIES

1977–1980s
Early Swiss and European studies: Monnier, Schoenenberger, and collaborators published a series of papers establishing that DSIP could be isolated from rabbit brain, induced sleep in animal models, and appeared to influence delta-wave activity on electroencephalography. EEG measures electrical patterns in the brain; delta waves are associated with deep slow-wave sleep. Some of these early studies also proposed effects on ACTH (adrenocorticotropic hormone) release and cortisol regulation, a potential anti-stress mechanism. These were the studies that established DSIP's scientific reputation. They used animal models and very small human samples measured by standards that predate modern sleep research methodology.
1985
ACTH/cortisol human trial (failed to replicate): A controlled human study (PMID 7777652) tested whether DSIP produced the ACTH and cortisol effects that had been proposed from earlier work. The cortisol suppression mechanism did not replicate. This is a significant negative result for DSIP's proposed anti-stress mechanism. When a proposed mechanism fails a direct human test, that mechanism should be treated as unconfirmed. It has not been adequately retested in modern studies with current methodology.
No modern data
Current clinical evidence: There are no registered Phase 2 or Phase 3 clinical trials for DSIP in any Western regulatory system. No IND is on file with the FDA. The literature base consists almost entirely of studies conducted in the 1970s and 1980s using methodology that predates modern sleep staging standards, blinded randomization protocols, and statistical rigor requirements. Some Russian research continued into the 1990s and 2000s, but it has not been independently replicated in Western GCP-standard trials. As of 2026, DSIP has the weakest modern human evidence base of any compound covered in Decoded.

WHAT THE STUDIES SHOW

WEAKLY SUPPORTED

  • ▸Delta sleep promotion in some early animal models
  • ▸DSIP is detectable in human blood and CSF (endogenous)
  • ▸Some early human studies showed subjective sleep improvement
  • ▸Historical data suggests it is not acutely toxic at low doses

NOT REPLICATED

  • ▸ACTH/cortisol suppression in humans (PMID 7777652 negative)
  • ▸Consistent delta sleep induction in modern controlled trials
  • ▸Effects are inconsistent across studies even in the original literature
  • ▸No identified receptor = no confirmed mechanism

UNKNOWN

  • ▸Gene encoding DSIP: not identified
  • ▸Primary receptor: not identified
  • ▸Physiological role of endogenous DSIP
  • ▸Safety at doses used in grey market: no controlled data

SIDE EFFECTS

REPORTED (ANECDOTAL)

  • ▸Injection site reactions
  • ▸Reported drowsiness or grogginess, consistent with claimed sleep effect
  • ▸Headache (reported in some users)
  • ▸No systematic safety data from controlled trials

NOTABLE / MONITOR FOR

  • ▸Grey market supply: purity and accurate concentration unverified
  • ▸No long-term safety data of any kind
  • ▸Unknown interactions with prescribed sleep medications or hormonal systems
  • ▸ACTH/cortisol effects are claimed but not confirmed. Do not assume this mechanism when making clinical decisions.

REGULATORY STATUS

FDA STATUS
Not approved · Regulatory gray zone post-April 2026
PHASE
No active trials · Pre-modern evidence base only
PROJECTED NDA
None · No development program

DSIP was included on the FDA's Category 2 list of bulk drug substances that raised concerns and were prohibited from 503A compounding. On April 15, 2026, the FDA removed DSIP along with 11 other compounds from that explicit prohibition. Removal from Category 2 does not mean DSIP is approved, compoundable, or cleared for clinical use. It means it is no longer explicitly listed as prohibited, while also not appearing on any approved compounding list. The PCAC (Pharmacy Compounding Advisory Committee) is scheduled to review DSIP and six other compounds on July 23–24, 2026, to evaluate whether 503A compounding eligibility is appropriate. The outcome of that review is unknown. Anyone obtaining DSIP is doing so through entirely unregulated channels, with no guarantee of purity, sterility, or accurate concentration.

PROS & CONS

PROS

  • +Endogenous peptide: the body produces it naturally, which limits some toxicity concerns
  • +Historical data suggests it is not acutely dangerous at low doses
  • +Some users report subjective sleep improvement, which is consistent with its historical framing
  • +No WADA ban as of current review (unlike some other peptides in this list)

CONS

  • −The defining mechanism (delta sleep induction) is not consistently replicated in modern humans
  • −The proposed cortisol-suppression mechanism failed in at least one direct human test
  • −No gene, no receptor, no confirmed mechanism of action
  • −Weakest evidence base of any compound in this Decoded series
  • −Grey market supply with no quality controls
  • −1970s and 1980s data is not a foundation for contemporary clinical use

DAILY PEPTIDE VERDICT

RANKING

Named for Something It Doesn't Reliably Do

DSIP is the most difficult compound in this series to write about responsibly, for one reason: the name itself is misleading. Delta Sleep-Inducing Peptide implies a well-characterized, reliably reproduced effect. Neither characterization is accurate. The compound is endogenous, it has a historical research footprint, and some users report benefit. But the ACTH and cortisol mechanism that would explain an anti-stress effect did not replicate in humans. Delta sleep induction is inconsistently reproduced even in the older literature. The gene has not been identified, the receptor has not been identified, and no modern controlled trial exists. Of any compound in this series, DSIP has the widest gap between its name and what the controlled evidence shows.

Also in GH SLEEP

// GH SLEEP

Tesamorelin

FDA APPROVEDPHASE 3+

// GH SLEEP

Sermorelin

COMPOUNDINGPHASE 3+

// GH SLEEP

CJC-1295 no DAC

GREY MARKETPHASE 1

DISCLAIMER · EDUCATIONAL USE ONLY

This document is for educational and informational purposes only. DSIP does not hold general FDA approval for human use. Information here synthesizes publicly available research data and does not constitute medical advice.