Buy DSIP Peptide Online | Delta Sleep-Inducing Peptide | ≥99% Purity | CoA | SourceTides

Buy DSIP Peptide Online from SourceTides.
DSIP (Delta Sleep-Inducing Peptide; CAS 62568-57-4) is a synthetic nonapeptide — a nine-amino acid sequence (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu; WAGGDASGE) first isolated in 1977 from the cerebral venous blood of electrically stimulated rabbits by Schoenenberger and Monnier at the University of Basel.
It is the only known neuropeptide whose gene and specific receptor have not yet been identified, making it one of the most scientifically unusual research compounds available.
DSIP is studied for delta-wave sleep induction, HPA axis modulation, antioxidant enzyme upregulation, neuroprotection in stroke and ischaemia models, and NMDA/GABA receptor interactions.
Every SourceTides vial is lyophilised, tested at ≥99% HPLC purity, and ships with a full lot-specific Certificate of Analysis.
For in-vitro laboratory research use only. Not for human consumption.

DSIP Peptide 5 mg — Technical Specifications

What Is DSIP?

DSIP stands for Delta Sleep-Inducing Peptide. It is a nine-amino acid neuropeptide — one of the smallest biologically active peptides studied for sleep and brain function. It was first isolated in 1977 by Schoenenberger and Monnier at the University of Basel, who collected it from the cerebral venous blood of rabbits whose thalamic nuclei were being electrically stimulated to induce sleep. When they isolated the dialysate from these rabbits and infused it into resting rabbits, the recipient animals showed the characteristic delta-wave EEG pattern of deep sleep. The active component turned out to be the nonapeptide WAGGDASGE — and they named it delta sleep-inducing peptide.

DSIP is genuinely unusual among neuropeptides. Despite nearly 50 years of research, scientists have never found its precursor gene or its specific receptor. It appears naturally in the hypothalamus, limbic system, pituitary, gut, pancreas, peripheral blood, cerebrospinal fluid, and even human breast milk — an extremely wide tissue distribution for a compound with no known gene. The current thinking is that DSIP either complexes with carrier proteins in the body (which would explain its longer apparent in-vivo effects vs its short 15-minute in-vitro half-life) or is a proteolytic fragment of a larger precursor that has not yet been characterised.

Research on DSIP spans multiple biological systems. Sleep biology is the most studied area — particularly its capacity to promote delta-wave (slow-wave) sleep, which is the deep sleep stage where most physical restoration and GH secretion occur. But DSIP’s research profile has expanded significantly since the 1990s into antioxidant biology, neuroprotection, stress hormone regulation, pain modulation, and most recently stroke recovery — where a 2021 study in MDPI Molecules confirmed significant motor function recovery in stroke-subjected rats (PMC8434407).

Researchers studying sleep architecture, circadian rhythm regulation, HPA axis biology, antioxidant enzyme expression, or ischaemia-reperfusion injury will find DSIP Peptide 5 mg from SourceTides a well-characterised but genuinely mysterious research compound with a unique combination of breadth and scientific intrigue.

How DSIP Works — Mechanism of Action

DSIP’s mechanisms are more complex and less completely defined than most research peptides — partly because its specific receptor remains unknown. What follows is what the published data shows, with honest notes on what is still debated.

Step 1 — Delta EEG Induction and Sleep Architecture Modulation

The founding mechanism of DSIP is its capacity to induce delta-wave EEG activity — the high-amplitude, low-frequency brainwaves (0.5–4 Hz) that define slow-wave sleep (SWS) or NREM Stage 3. In the original rabbit model, intraventricular infusion produced a 35% mean increase in EEG delta activity compared to controls, with the effect specific to the alpha-aspartyl WAGGDASGE sequence (the beta-Asp isomer was inactive). This is not simply a sedative effect — DSIP does not suppress EEG activity broadly. It selectively enhances the delta wave component of sleep architecture while allowing the subject to remain arousable and maintaining normal sleep stage progression. The mechanism by which this selectivity is achieved is not yet fully understood, but NMDA receptor modulation and GABAergic system interaction are the leading proposed pathways. Delta-wave sleep is the stage during which growth hormone secretion peaks, metabolic waste is cleared from the brain via the glymphatic system, protein synthesis and tissue repair are prioritised, and memory consolidation occurs. DSIP research in this domain uses polysomnography (PSG) with EEG delta power analysis as the primary endpoint.

Step 2 — NMDA Receptor Modulation and Glutamate System Interaction

DSIP modulates glutamatergic signalling via NMDA receptors — one of the most important receptor systems in the brain for learning, memory, sleep regulation, and neuroprotection. Specifically, DSIP has been shown to block presynaptic NMDA receptors in cultured rat cortical neurons, and to reduce glutamate- or NMDA-stimulated calcium uptake into synaptosomes. This anti-excitotoxic action — reducing excessive glutamate-driven calcium influx — is directly relevant to stroke research, where NMDA-mediated excitotoxicity is a primary driver of ischaemic neuronal death. The NMDA modulation also provides a mechanistic basis for DSIP’s sleep effects: NMDA receptor activation is pro-arousal, and DSIP’s partial suppression of NMDA activity would shift the balance toward inhibitory GABA tone and delta-wave production.

Step 3 — HPA Axis Modulation and Stress Response

DSIP has been studied as a potential modulator of the hypothalamic-pituitary-adrenal (HPA) axis — the stress response system that controls cortisol and ACTH secretion. Animal studies show that DSIP administration attenuated stress-induced corticosterone elevation in rodents, reduced ulcer formation under immobilisation stress, and normalised stress-disrupted circadian hormone rhythms. DSIP was also shown to co-localise with ACTH and other stress hormones in the pituitary, suggesting a paracrine regulatory role. However, the human data on this mechanism is more equivocal. A controlled study in healthy men (Rivier et al.; PubMed PMID: 7777652) found that IV DSIP did not significantly inhibit CRH-stimulated ACTH and cortisol secretion — a direct contradiction of the in-vitro corticotropin-release inhibiting factor data. This human-animal discrepancy is one of the genuine unresolved puzzles of DSIP research and should be noted clearly in any experimental design relying on DSIP’s stress-modulation properties.

Step 4 — Antioxidant Enzyme Upregulation

One of DSIP’s most consistent effects across multiple model systems is the upregulation of endogenous antioxidant enzymes. Khvatova et al. (2003) demonstrated that DSIP (12 µg/100 g body weight) significantly increased the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GPX), and glutathione reductase (GR) in rat tissues and erythrocytes. In stressed animals, preliminary DSIP restored the prooxidant-antioxidant balance and normalised myeloperoxidase activity in blood neutrophils. The mechanism appears to be increased gene expression of these antioxidant enzymes — confirmed in ageing animal studies. This antioxidant axis connects DSIP’s sleep biology and neuroprotection research: oxidative stress is a major driver of both poor sleep quality (through cortisol dysregulation and mitochondrial damage) and ischaemic brain injury. DSIP’s upregulation of SOD and GPX provides a mechanistic pathway for both its sleep-restorative and neuroprotective effects.

Step 5 — Neuroprotection in Ischaemia-Reperfusion Models

The most recently published research domain for DSIP is neuroprotection in stroke and cardiac ischaemia models. A 2021 study published in MDPI Molecules (PMC8434407; full text) showed that DSIP produced significant motor function recovery in Sprague-Dawley rats subjected to focal stroke, as measured by rotarod testing and other motor performance assays. The proposed protective mechanisms include: anti-excitotoxic NMDA receptor blockade (reducing calcium overload during ischaemia), SOD/GPX upregulation (reducing ROS damage during reperfusion), and correction of neuromediator imbalances under hypoxia. A closely related study on KND peptide — a structural DSIP analog — showed a 32% reduction in myocardial infarction area and significant brain infarction volume reduction when administered during reperfusion. These ischaemia-reperfusion studies represent the most rigorous recent preclinical evidence for DSIP and open a new research direction well beyond the original sleep biology applications.

DSIP Research Evidence

DSIP: The Sleep Biology Deep-Dive

To understand why DSIP matters in sleep research, you first need to understand what delta sleep actually is — and why it is the most important sleep stage for physical and cognitive recovery.

What Delta Sleep Is and Why It Matters

Sleep is not a single state. It cycles through five stages: NREM Stages 1, 2, and 3 (slow-wave sleep), plus REM sleep, in roughly 90-minute cycles throughout the night. Delta sleep — NREM Stage 3, also called slow-wave sleep (SWS) — is the deepest stage. It is named for its dominant brainwave pattern: high-amplitude, 0.5–4 Hz delta waves that signal the brain is in its most restored, most anabolic, and least aroused state.

Delta sleep is when the most important restoration happens. Growth hormone secretion peaks during SWS — roughly 70% of daily GH is released during the first deep sleep cycle of the night. The glymphatic system clears metabolic waste from the brain, including amyloid-beta proteins implicated in Alzheimer’s disease. Protein synthesis, immune cell activity, and metabolic repair are all prioritised. Cortisol hits its daily nadir. Memory consolidation of procedural tasks occurs. People deprived of delta sleep report waking up exhausted, sore, cognitively impaired, and immunologically weakened — despite having spent adequate time in bed. Chronic delta sleep deficiency is linked to obesity, insulin resistance, cardiovascular disease, and accelerated neurodegeneration.

DSIP’s relevance is that it selectively promotes this specific sleep stage — not sleep in general, and not sedation. This selectivity is its defining research characteristic.

The Human Insomnia Trial

The most rigorous human evidence for DSIP’s sleep effects comes from a double-blind, matched-pairs, parallel-group study in 16 chronic insomnia patients (PubMed PMID: 1299794). Patients received DSIP (25 nmol/kg IV) or glucose placebo on three consecutive afternoons before sleep, with polysomnography measuring sleep architecture objectively. The DSIP group showed statistically significant improvements in sleep efficiency and shorter sleep latency compared to the placebo group. The study noted the effect size as weak-to-moderate — honest characterisation that the improvement was real but not dramatic. Earlier studies in alcohol withdrawal patients reported normalisation of sleep architecture, and a study combining DSIP with standard anaesthesia actually found an unexpected increase in heart rate and reduced anaesthetic depth — a result that highlights the complexity of DSIP’s CNS effects and the importance of careful control conditions in sleep research designs.

The Unresolved Mystery

What makes DSIP uniquely fascinating as a research compound is what we don’t know about it. After nearly 50 years of published research, no one has found its gene, its precursor protein, or its specific receptor. It is the only neuropeptide for which this is true. Research reviews have called it “a still unresolved riddle.” Its in-vitro half-life is only 15 minutes — yet its in-vivo effects persist for hours, suggesting carrier protein binding or a precursor relationship we have not yet characterised. It circulates in human plasma and cerebrospinal fluid naturally, co-localises with multiple pituitary hormones, and appears in peripheral tissues far from the CNS — yet no gene for it has been found through extensive genomic searches. For researchers in neuropeptide biology, receptor pharmacology, or sleep science, this mystery is a genuine invitation to discovery.

What Is DSIP Used for in Research?

DSIP Pharmacokinetics

DSIP Side Effects and Safety Profile

DSIP Quality Control at SourceTides

Every batch of DSIP Peptide 5 mg from SourceTides passes these tests before release. DSIP’s α-aspartyl requirement (only the α-Asp configuration is biologically active) makes isomer confirmation by mass spectrometry particularly important for this compound.

DSIP Regulatory Status

DSIP vs Related Sleep and Neuroprotective Research Peptides

Peer-Reviewed References

Frequently Researched Alongside DSIP

These compounds are commonly studied alongside DSIP in sleep, circadian, and neuroprotective research:

• Epithalon 10 mg — Pineal bioregulator targeting melatonin restoration and circadian rhythm; studied alongside DSIP for combined sleep architecture (delta-wave) and melatonin circadian axis research
• Pinealon 10 mg — CNS neuroprotection via antioxidant gene regulation; complementary to DSIP’s antioxidant enzyme upregulation and neuroprotection in stroke models
• Sermorelin 10 mg — GHRH agonist; delta sleep is when GH secretion peaks; DSIP and Sermorelin are complementary tools for studying the sleep-GH coupling axis
• Ipamorelin 10 mg — GH secretagogue; studied alongside DSIP in protocols examining how delta sleep quality and GH pulse amplitude interact
• Thymalin 10 mg — Thymic immune bioregulator; studied alongside DSIP in ageing protocols combining sleep-immune axis research (delta sleep deprivation is immunosuppressive)

Frequently Asked Questions