DSIP

DSIP is a nonapeptide with the amino acid sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu, carrying a molecular weight of approximately 850 daltons. It was first isolated in 1974 from cerebral venous blood of sleeping rabbits by the Schoenenberger-Monnier group in Basel and is detected endogenously in human plasma, cerebrospinal fluid, urine, and breast milk. It localizes to the hypothalamus, limbic system, and pituitary, where it co-localizes with ACTH, MSH, TSH, and glucagon.

No dedicated high-affinity receptor for DSIP has been identified. Proposed intracellular signaling involves interaction with NMDA receptors, structural homology to glucocorticoid-induced leucine zipper (GILZ), and putative engagement of the MAPK cascade. The peptide crosses the blood-brain barrier via a saturable, carrier-mediated transport system distinct from passive diffusion; regional transfer constants in guinea pig brain range from 0.93 µL/min/g in parietal cortex to 1.66 µL/min/g in hippocampus and are competitively inhibited by L-tryptophan at physiological concentrations.

At the neurotransmitter level, DSIP activates GABAergic signaling and inhibits serotonin, noradrenaline, and histamine pathways. It inhibits somatostatin release via a dopaminergic mechanism and stimulates Met-enkephalin release, providing an indirect link to the opioid peptidergic system. In brain tissue, DSIP also induces MAO-A activity and RNA synthesis. A phosphorylated analog (DSIP-P, modified at serine-7) demonstrates greater potency than the parent peptide. In vitro half-life is approximately 15 minutes due to aminopeptidase-like enzymatic degradation.

The published human evidence base for DSIP is small, predominantly dated to the 1980s and early 1990s, and characterized by very small sample sizes, intravenous administration routes, and mixed outcomes. No large, preregistered, modern randomized controlled trial has been conducted.

In a double-blind matched-pairs randomized study at the University of Amsterdam (Schneider-Helmert 1992, PMID 1299794, n=16 chronic insomniac patients), participants received intravenous DSIP at 25 nmol/kg or glucose placebo before three consecutive laboratory nights. Polysomnographic data showed higher sleep efficiency and shorter sleep latency in the DSIP group versus placebo, but the authors described these effects as "statistically weak," noted no improvement in subjective sleep quality, and concluded that short-term treatment with DSIP "is not likely to be of major therapeutic benefit" for chronic insomnia.

A 1981 Lancet communication (Schneider-Helmert, Graf, and Schoenenberger, PMID 6112579) reported improvement in insomnia with synthetic DSIP in a randomized format, but no abstract is publicly available for detailed evaluation of sample size or effect magnitude.

A 1984 European Neurology pilot study (Larbig et al., PMID 6548970, n=7) administered DSIP intravenously to patients with chronic pain conditions including migraine, tinnitus, and psychogenic pain; 6 of 7 patients showed significant pain reduction alongside a reduction in depressive symptoms. The extreme small sample size limits interpretation.

A 1983 Neuropsychobiology study (PMID 6328354, n=49 evaluable) administered DSIP 25 nmol/kg IV as the sole treatment for opioid or alcohol withdrawal syndrome; 48 of 49 patients showed immediate benefit with rapid resolution of somatic symptoms. No major adverse effects were recorded. These findings have not been replicated in a controlled trial.

Animal data include anticonvulsant effects in metaphit-induced epilepsy models, intracerebroventricular antinociception, and a reported 2.6-fold reduction in spontaneous tumor incidence in mice. A 2006 review (Kovalzon and Strekalova, Journal of Neurochemistry, PMID 16539679) concluded that DSIP's role in sleep regulation remains "obscure" and proposed that endogenous DSIP-like peptides rather than the nonapeptide itself may account for observed biological effects, as no DSIP gene or receptor has been characterized.

Typical dosage: 100-300 mcg (before bed).

Human clinical trials uniformly employed intravenous administration at 25 nmol/kg body weight. For an adult weighing 70 kg this corresponds to approximately 1,750 nmol, or roughly 1.5 µg/kg, delivered by slow infusion; the exact microgram totals vary with molecular weight calculations and formulation purity. This was the only route tested in published RCTs, and bioavailability by other routes has not been established in human studies.

In contemporary off-label and compounding contexts, subcutaneous injection doses of 100–300 µg are most commonly cited in practitioner and research-peptide communities, administered approximately 30–60 minutes before intended sleep onset. Some protocols describe 8–12 consecutive dosing days followed by a treatment break, loosely modeled on the multi-injection schedules employed in the 1984 chronic-pain pilot study. The phosphorylated analog DSIP-P is sometimes described as requiring lower absolute doses due to greater potency, but no published human dose-ranging study for this analog exists.

Reconstituted peptide is typically stored refrigerated at approximately 4°C and should be used within a defined window after reconstitution. There is no consensus on cycle length, frequency of repeat courses, or dose adjustment for renal or hepatic impairment.

This information is provided for educational and reference purposes only and does not constitute medical advice. DSIP is not approved by the U.S. Food and Drug Administration or any major regulatory authority for any therapeutic indication. Administration outside a supervised clinical or research context carries unknown risks.

No compound-specific stability data has been identified for this peptide. The general lyophilized-peptide handling framework applies — see Storage & handling for temperature, reconstitution diluent, and beyond-use dating principles.

No peer-reviewed human study has prospectively evaluated DSIP in combination with other agents. The following combinations appear in practitioner literature and community discussions and are entirely anecdotal.

• Melatonin combined with DSIP: the stated rationale is complementary mechanism — melatonin regulates circadian timing of sleep onset while DSIP is proposed to deepen slow-wave sleep architecture. Users report lower doses of each compound when combined, though concurrent use of two CNS-active agents increases the risk of excessive sedation (anecdotal only).

• Magnesium (glycinate or threonate formulations) combined with DSIP: magnesium supports GABA receptor function and neuromuscular relaxation. The combination is described as additive rather than synergistic, with relatively low pharmacological interaction risk at standard nutritional doses, but no formal data exist (anecdotal only).

• Growth hormone secretagogues (GHRP-2, ipamorelin, or CJC-1295) combined with DSIP: some practitioners report stacking DSIP with GH-releasing peptides to leverage the slow-wave sleep window for endogenous GH pulsatility. No published human data support any synergistic effect or evaluate safety of this combination (anecdotal only).

DSIP is not currently FDA-approved for any indication. Effective April 22, 2026, the FDA removed DSIP from Category 2 of its Section 503A bulk drug substances list after the original nominators withdrew their nominations. This removal lifts the prior “significant safety risk” designation but does not place DSIP on the 503A Bulks List. Compounding pharmacies may prepare it with a valid physician prescription and pharmaceutical-grade API from an FDA-registered manufacturer. The FDA’s Pharmacy Compounding Advisory Committee (PCAC) is scheduled to review this substance at its July 23–24, 2026 public meeting. Removed from FDA Category 2 effective April 22, 2026. Selected for PCAC review Day 2 — July 24, 2026. PCAC agenda: DSIP (Emideltide), Semax, Epitalon. NOT currently on 503A Bulks List — requires physician Rx. Source: FDA Advisory Committee Calendar / Lengea Law, May 2026.

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Reported side effects: Very well-tolerated, possible grogginess

Small clinical trials from the 1980s characterized DSIP as generally well tolerated within the intravenous doses used. The 1983 withdrawal study (n=49) explicitly noted no major adverse effects. Transient headache, nausea, and vertigo are the most frequently reported adverse effects across published human studies and community reports. Daytime drowsiness has been noted when dosing is mistimed or exceeds effective thresholds.

More significant safety concerns arise from regulatory review rather than clinical data. The U.S. FDA classified DSIP (also designated emideltide or emideltide acetate) in Category 2 of the 503A bulk compounding substances list, citing potential immunogenicity — the risk that exogenous peptide material may provoke an immune response, including anaphylactoid reactions. This classification restricted compounded DSIP from routine dispensing pending review by the Pharmacy Compounding Advisory Committee. Research-grade peptide products, which may carry process-related impurities, are considered to carry higher immunogenicity risk than pharmaceutical-grade compounded preparations.

Long-term safety data are absent; no chronic dosing study in humans has been published. Because DSIP engages GABAergic, opioidergic, and hypothalamic-pituitary signaling axes, pharmacodynamic interactions with sedative-hypnotics, benzodiazepines, opioids, and hormonal therapies are biologically plausible but have not been characterized. DSIP may also interact with peptidase inhibitors such as captopril, potentially prolonging peptide half-life unpredictably. Contraindications have not been formally established; use is generally not advised in pregnancy or lactation (DSIP is detectable in human breast milk), in individuals with active malignancy, or in those with autoimmune conditions, based on mechanistic concern rather than direct clinical evidence.