DSIP

DSIP (delta sleep-inducing peptide) is a short, naturally occurring peptide made of nine amino acids. It was isolated in 1977 from the cerebral venous blood of rabbits held in slow-wave sleep by thalamic stimulation ¹¹. A 2026 review groups DSIP with epithalon and pinealon as recovery-enhancing peptides that act on circadian and mitochondrial regulators ¹.

The evidence base has three main features. First, human trials are small and mostly decades old, focused on chronic insomnia ⁹ and a chronic-pain pilot ¹². Second, animal research spans sleep, seizures, analgesia, and ischemia protection, often showing a bell-shaped dose-response curve in which higher doses can become less active ¹³. Third, no DSIP gene, receptor, or precursor has ever been identified, so the endogenous signaling system remains unresolved ¹⁴.

What the research does support is practical. Intact DSIP crosses the blood-brain barrier by passive, non-saturable diffusion ¹⁵. In animal models, it reduces stress-hormone release at the pituitary level ¹⁸ and stimulates growth-hormone release ²². The open questions are route, dose, and duration in humans, especially because the plasma half-life is only about 2 to 4 minutes ¹⁹.

DSIP is best described as a central neuromodulator rather than a classical ligand with one dedicated receptor. No encoding gene or receptor has been cloned, and the sequence does not resemble a known peptide family ¹⁴. Some DSIP-like material in tissue may actually be related peptides, not the nine-amino-acid peptide itself ¹⁴.

The best-characterized pathway is dopaminergic disinhibition. In rat median-eminence tissue, DSIP inhibits the release of somatostatin, a neuropeptide that brakes several downstream pathways, and this effect is blocked by the D2 dopamine antagonist pimozide ²⁵. Lower somatostatin tone may help explain some of the peptide's neuroendocrine actions.

A second pathway is opioidergic coupling. DSIP stimulates Met-enkephalin release from brainstem slices ¹⁶, and naloxone, an opioid receptor blocker, reverses several DSIP effects in rats ²⁶. The sleep and memory benefits of phosphorylated DSIP under simulated high altitude also disappear when naloxone is given ⁵.

A third theme is monoamine and amino-acid rebalancing. Under hypoxic stress, DSIP partly prevents stress-driven changes in monoamine oxidase A activity and serotonin ²⁷. Phosphorylated DSIP reduces excitatory catecholamine drive and increases inhibitory GABA-synthetic capacity while preserving cholinergic tone ⁵.

On the stress axis, intravenous DSIP at 5 to 30 micrograms per kilogram blunt CRF-stimulated corticosterone in rats without changing ACTH-elicited release, which points to a pituitary-level action ¹⁸. In healthy humans, however, DSIP did not alter CRH- or meal-induced ACTH and cortisol secretion ²¹.

Pharmacokinetics shape the interpretation of all of this. The plasma half-life is about 4 minutes in dogs and 2 to 3 minutes in rodents and monkeys ¹⁹. The intact peptide crosses the blood-brain barrier by passive, bidirectional diffusion ¹⁵, so fast clearance does not rule out central effects, but it makes timing part of any protocol. A naturally occurring phosphorylated form, DSIP-P, is more potent than native DSIP ¹¹.

Sleep and circadian effects

The strongest human evidence is mixed. A double-blind, placebo-controlled crossover trial in 14 people with severe chronic insomnia found that a 7-night intravenous course improved night sleep from the first dose, with the benefit persisting through the first post-treatment night; daytime alertness and performance also normalized ¹⁰. A separate 3-night trial using 25 nmol/kg IV in 16 people found only weak improvements in sleep efficiency and latency and concluded that short-term DSIP was unlikely to be of major therapeutic benefit ⁹.

Animal models are more consistent. Rabbits show more light non-REM sleep and cats show more REM sleep, both with bell-shaped dose-response curves ¹³. A blood-brain-barrier-crossing DSIP fusion peptide restored neurotransmitter balance and sleep in insomnia-model mice ². Phosphorylated DSIP at 10 micrograms per kilogram daily enhanced NREM and REM sleep under simulated high altitude and improved spatial memory ⁵.

Pain, stress, seizures, ischemia, and aging

• Pain: DSIP produced analgesia in mice and stimulated Met-enkephalin release, consistent with opioid-system involvement ¹⁶. In a 7-patient open pilot, intravenous dosing for 5 consecutive days followed by injections every 48 to 72 hours reduced pain in 6 of 7 people, with depressive symptoms improving alongside pain ¹².
• Stress axis: DSIP at 5 to 30 micrograms per kilogram IV reduced CRF-stimulated corticosterone in rats ¹⁸.
• Seizures: DSIP 1 mg/kg intraperitoneally reduced seizure intensity, lengthened latency, and shortened EEG ictal periods in a drug-refractory seizure model ⁶.
• Ischemia: intranasal DSIP after experimental stroke accelerated motor recovery in rats, although infarct-volume reduction was not significant ³. Administering DSIP or the analogue KND during active occlusion was fatal in animal models, while reperfusion-phase dosing reduced infarct size ⁴.
• Aging: the DSIP-containing preparation Deltaran improved aging biomarkers, extended lifespan, and reduced spontaneous tumor incidence in female SHR mice ⁷.

Published human protocols are short and were mostly intravenous.

• Insomnia trials: one double-blind RCT used 25 nmol/kg IV once nightly before bed for 3 nights ⁹. That dose equals roughly 21 micrograms per kilogram, or about 1.5 mg for a 70 kg adult ⁹. A second RCT used nightly intravenous dosing for 7 consecutive nights and saw sleep and daytime function normalize by the end of the first treatment week ¹⁰.
• Pain pilot: an older open study used daily intravenous dosing for 5 consecutive days, then maintenance injections every 48 to 72 hours over roughly 2 to 3 weeks ¹².
• Community research patterns: community protocols usually use much lower subcutaneous doses, commonly 100 to 250 micrograms once nightly, 30 to 60 minutes before bed, with typical cycles of 4 to 8 weeks. The timeline on this page shows a representative pattern.

Dose-response is not linear. Animal models repeatedly show a bell-shaped curve, meaning doses above the effective window tend to reduce the effect ¹³. Practitioner guidance is to start at the low end, around 100 micrograms, and only adjust toward 250 micrograms after a week without response [practitioner consensus].

Timing matters. In animal chronopharmacology, phosphorylated DSIP given at 18:30, the start of the active period, improved sleep and restored memory under simulated altitude ⁵. Evening administration aligns with the evening decline in HPA tone, and afternoon dosing has been suggested as one reason the 3-night human trial underperformed given the minutes-fast half-life ⁹.

DSIP is supplied as a lyophilized powder that is freely water-soluble ⁴⁴. The standard diluent is bacteriostatic water (0.9% benzyl alcohol); sterile water for injection is acceptable for single-use research vials. Add the diluent slowly against the vial wall and swirl gently until the solution clears. Avoid vigorous shaking, which can cause foaming and surface aggregation.

Unreconstituted vials should be stored sealed and protected from light and moisture: 2 to 8 °C for short periods or −20 °C for longer storage. After reconstitution, store at 2 to 8 °C and use within about 30 days. Do not repeatedly freeze-thaw, and do not pre-dilute DSIP in plasma or serum because it degrades and aggregates there rapidly ¹¹.

The peptide is enzymatically fragile. A human cerebrospinal-fluid aminopeptidase cleaves DSIP ⁴⁶, brain extracts remove the N-terminal tryptophan with about a 15-minute half-life ¹¹, and intravenous plasma clearance is minutes-fast ¹⁹. This is why research protocols prepare the peptide close to the dosing window and rely on downstream central signaling rather than sustained blood levels. The calculator below handles the specific diluent volumes and concentrations for typical vials.

Drug interactions

Formal drug-interaction trials do not exist, so the interaction profile is built from mechanism and animal or human experimental data.

• Sedative-hypnotics: a DSIP fusion construct potentiated pentobarbital hypnosis in mice, producing shorter sleep latency and longer sleep duration ¹³. DSIP also altered bispectral index, EEG, and heart-rate variability under isoflurane anesthesia in humans ³³. Additive sedation is the most clinically relevant interaction.
• Opioid agonists: DSIP engages endogenous opioid circuitry ¹⁶ and showed analgesic benefit in a small chronic-pain pilot ¹². Additive analgesia or sedation with full opioid agonists is plausible but unstudied.
• Opioid antagonists: naloxone blocks DSIP's sleep and memory effects in rats ²⁶. Naltrexone or buprenorphine may blunt the peptide's sleep and analgesic endpoints ⁵.
• Antiepileptic drugs: DSIP reduced seizure severity on its own ⁶ and potentiated valproate's anticonvulsant effect in animal models ³⁸.
• Dopamine antagonists: pimozide blocks DSIP's inhibition of somatostatin release ²⁵, so D2 blockers could blunt some effects.
• Corticosteroids and HPA-active drugs: DSIP did not affect CRH- or meal-induced ACTH and cortisol secretion in healthy humans ²¹, so no routine adjustment is grounded.

Supplement interactions

• Melatonin: DSIP raises melatonin in an insomnia model ², and overlapping sleep effects make additive morning grogginess possible.
• Sedating botanicals, magnesium, L-theanine, glycine: additive sedation is inferred from barbiturate and isoflurane potentiation ¹³.
• 5-HTP and tryptophan: serotonergic overlap is based on DSIP's effects on serotonin under stress ²⁷; one serotonergic agent at a time is the research-conservative approach.
• Caffeine and stimulants: these oppose the sleep-promoting direction; research practice separates them from DSIP by several hours.

Peptide interactions

• GH secretagogues: DSIP stimulates growth-hormone release through hypothalamic and pituitary actions distinct from GHS-R agonism ²², so combinations with ipamorelin, CJC-1295, or sermorelin are mechanistically additive in theory but lack human combination data.
• Recovery peptides: BPC-157, TB-500, and GHK-Cu have no shared mechanism with DSIP but are commonly co-used in sleep and recovery protocols. Because of the ischemia-timing mortality signal, DSIP should be withheld in acute tissue-injury settings until reperfusion is established ⁴.
• Arousal peptides: semax and high-dose selank have an opposing valence to DSIP; research protocols often separate them by circadian phase.
• PT-141 and kisspeptin-10: all three modulate male copulatory behavior in rats ³², but no human stacking evidence exists.

Tolerance was not observed in the human trials that used repeated dosing. Sleep benefit appeared on the first night, improved with nightly dosing, and persisted through the first post-treatment evening in one 7-night RCT ¹⁰. Community reports, however, often describe diminishing sleep benefit by weeks 2 to 3 of a cycle without a break.

The human literature is short-course by design: 3 nights ⁹, 7 nights ¹⁰, or a scaled 2 to 3 week pain protocol with spacing every 48 to 72 hours ¹². Animal courses were also time-limited, including 8 days of intranasal dosing after experimental stroke ³.

Cycling follows from the dose-response shape. DSIP shows bell-shaped curves in several animal models ¹³, so when benefit fades, raising the dose is unlikely to rescue the cycle. The evidence-consistent move is to end the course and take a break [practitioner consensus].

Community protocols use two common patterns. One is a short sleep reset of 5 to 10 nights followed by 2 to 4 weeks off. The other is a 4 to 8 week course with a 5-on/2-off weekly pattern, followed by 2 to 4 weeks off. Longer variants such as 2 weeks on / 2 weeks off or 3 weeks on / 1 week off exist but have no comparative data.

Pharmacokinetics make clean cycle boundaries natural. DSIP is eliminated in minutes with no meaningful tissue accumulation ¹⁹, so a course needs nightly dosing, and stopping should be abrupt. No rebound insomnia or withdrawal was documented in the human sleep studies ¹⁰.

DSIP appears in community sleep and recovery stacks, but almost all of the evidence is mechanistic rather than based on human combination trials.

• Sleep stacks: DSIP is often paired with melatonin or modest doses of sedating botanicals. Both pathways are hypnogenic, and DSIP raises endogenous melatonin in an insomnia model ², so the main practical interaction is additive sedation.
• GH-axis stacks: DSIP is combined with ipamorelin, CJC-1295, or sermorelin in nocturnal recovery protocols. The mechanistic case is reasonable: DSIP stimulates growth-hormone release through hypothalamic and pituitary actions ²², while GHRP and GHRH-type secretagogues act through different receptors. No human combo data exist.
• Tissue recovery stacks: BPC-157, TB-500, and GHK-Cu are common co-components for sleep and recovery. They have no documented shared mechanism with DSIP. The one hard constraint from the DSIP literature is ischemia timing: DSIP or its analogue KND during active occlusion was uniformly fatal in animal models, while reperfusion-phase dosing was protective ⁴.
• Cognition and circadian stacks: epithalon and pinealon are classified with DSIP as recovery-enhancing peptides acting on circadian and mitochondrial regulators ¹. Arousal peptides such as semax or high-dose selank counter the sleep direction, so research protocols tend to split them by time of day.
• Sexual function stacks: DSIP, PT-141, and kisspeptin-10 all modulate male copulatory behavior in rats ³². The DSIP effect in that literature was transient, and combination safety is unknown.

Because no DSIP receptor has been identified ¹⁴, predicting true synergy or off-target amplification is difficult. Stacking is best treated as adding unknowns to an already unresolved system.

DSIP is not FDA-approved for any indication and has no EMA marketing authorization. It is not a controlled substance in the United States, and the Federal Analogue Act does not reach it because its nine-amino-acid sequence is unrelated to any scheduled substance. However, products marketed for human use would still be treated as unapproved new drugs, and the peptide falls outside the dietary-supplement definition. A 2021 survey identified DSIP in illegally distributed peptide products by mass spectrometry, alongside GHRP-2, GHRP-6, ipamorelin, BPC-157, melanotan II, and thymosin beta-4 ²³.

The unresolved molecular identity is a regulatory problem as well as a scientific one: no DSIP gene, receptor, or biosynthetic pathway has been isolated, and the source of plasma DSIP-like immunoreactivity is not established ¹⁴. Those gaps would complicate any future clinical-registration program.

International status is similar in most regions: no EMA registration, no UK licensed product, no ARTG listing in Australia, and personal import of injectable DSIP is treated as an unapproved prescription medicine at borders. Russia is the notable historical exception through Deltaran, a DSIP-containing preparation studied for longevity, physiological function, and antistress protection in animal models ⁵¹; its current registration status is not documented in the reviewed literature.

For sport, no WADA prohibition was identified in the reviewed literature. WADA's catch-all S0 class for non-approved substances applies in principle, and S0 substances are not eligible for therapeutic-use exemptions. No DSIP-specific athlete sanction or adverse analytical finding is documented in the public record.

Across the small human trials and the pain pilot, DSIP was well tolerated with no serious adverse events reported ⁹. The most commonly reported human effect is sedation or sleepiness, which is also the intended direction of use. Next-day performance was not impaired in the 7-night trial; in fact, daytime alertness and performance normalized ¹⁰.

The most important safety signal is ischemia timing. In animal models, DSIP or its analogue KND given during ongoing coronary or cerebral artery occlusion caused 100% mortality, while reperfusion-phase dosing reduced infarct size ⁴. Research guidance therefore treats active myocardial ischemia, unstable angina, acute stroke, and TIA as hard stops, and DSIP is not an acute-ischemia therapy.

Other side-effect signals are drawn from animal or in-vitro work and have not been confirmed in humans:

• Opioid interactions: naloxone blocks major DSIP effects in rats ²⁶, and the peptide's activity partly depends on endogenous opioid circuitry ¹⁶. People on naloxone, naltrexone, or buprenorphine may see blunted sleep or analgesic effects.
• Parkinsonian signs: direct infusion into the substantia nigra produced a Parkinsonian syndrome in rats ³⁶. Peripheral low-dose use has not been linked to this.
• Endocrine shifts: DSIP stimulated growth-hormone release ²² and luteinizing-hormone release without FSH ³⁹ in rats, and induced pituitary cell differentiation in vitro ²⁸. Chronic consequences in humans are unstudied.
• HPA-axis dampening: DSIP blunted CRF-stimulated corticosterone in rats at the pituitary level ¹⁸, but healthy-human CRH challenges showed no change ²¹.
• Sedative and anesthetic interactions: DSIP changed EEG, bispectral index, and heart-rate variability under isoflurane anesthesia ³³. Use should be disclosed before sedation or surgery.
• Paradoxical response: reduced sleep was seen in cats after intraperitoneal DSIP ³⁷, consistent with the bell-shaped dose-response ¹³.

Formal adverse-event collection was not performed in the human trials, so side-effect frequencies cannot be quantified ⁹. Safety beyond roughly 3 weeks of exposure is unknown, and the quality of grey-market peptide products is unverified ²³.