DSIP (Delta Sleep-Inducing Peptide / Emideltide)
DSIP (Emideltide) — evidence, the discovery story & status

Class: peptide
Synonyms: DSIP
Delta Sleep-Inducing Peptide
Emideltide (the name the FDA uses in the Federal Register)
nonapeptide
sequence Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu (WAGGDASGE)
CAS 62568-57-4. INCI: none
Function tags: sleep / circadian
(also studied:) withdrawal, stress, pain — research context
Overall evidence grade: C
WADA prohibited: no
Last updated: 2026-07-04

In brief: DSIP (regulatory name Emideltide) is a naturally occurring nonapeptide named for its ability to promote delta (deep-sleep) EEG in rabbits. But despite roughly 50 years of study, the human evidence that it reliably induces sleep is limited, mixed and contradictory — the best-designed trial found only weak effects — its mechanism and even its receptor are unknown, and it is not approved anywhere. The name is more definitive than the data.

## Identity a naturally occurring **nonapeptide** (9 amino acids, ~849 Da; < 40 aa → peptide), amphiphilic, notable for crossing the blood-brain barrier and being unusually absorbed via the gut. Found in small amounts in brain, pituitary, gut, blood and breast milk. **Unusually, it has no identified receptor**, and the gene has not been found — a basic-biology gap that matters when reading the "mechanism." ## Development & history - Isolated in **1974** (characterised in *PNAS* 1977) by the Swiss group **Guido Schoenenberger and Marcel Monnier** at the **University of Basel**, from the **cerebral venous blood of rabbits in an electrically-induced sleep state.** Infused into other rabbits, the peptide increased **delta-frequency (deep-sleep) EEG activity** — which is exactly how it got its name.
- **The mystery:** decades later, **no DSIP receptor or precursor gene has been identified in rabbits**, and BLAST searches align the sequence with a hypothetical *Amycolatopsis coloradensis* protein — raising the possibility that **DSIP may be of bacterial origin.** In other words, the compound's fundamental biology is still unsettled. ## Mechanism (as proposed), and it is not approved anywhere. **The name is more definitive than the data.**

Evidence grades by outcome:
outcome: Delta / slow-wave EEG (animal)
grade: C
base: Monnier & Schoenenberger 1977 (rabbit)
effect: Increased delta activity
caveat: The original finding; animal, and even here later work was mixed
outcome: Chronic insomnia (human)
grade: C
base: Small 1980s studies (Schneider-Helmert) + Bes et al. 1992
effect: Mixed; some positive, but the strongest trial showed only weak effects
caveat: Human evidence is limited and contradictory — the "sleep-inducing" name overpromises
outcome: Opioid / alcohol withdrawal, stress, pain
grade: D
base: Older, small studies
effect: Suggestive
caveat: Thin; not replicated to modern standards
outcome: Mechanism / receptor
base: —
effect: Unknown
caveat: No confirmed receptor; gene not identified; possible bacterial origin
outcome: Safety
base: No modern human safety RCT
effect: Unknown
caveat: Long-term safety not established

Legal status:
region: EU
status: Not approved
note: Not approved; not eligible for magistral/officinal compounding.
region: US
status: Not FDA-approved (503A Cat. 2)
note: Not FDA-approved. Placed in 503A Category 2 (Sept 2023); scheduled for PCAC review in July 2026 under the name Emideltide, covering proposed uses in opioid withdrawal, chronic insomnia and narcolepsy (docket FDA-2025-N-6895). A change in review status — not an approval.
region: INT
status: Approved nowhere
note: Approved nowhere.

Cosmetic claims:

Note: Research / reference — not for sale, not approved. The honest crux here: the name is a claim the human evidence doesn't robustly support. ~50 years of study, mixed and contradictory results, and — remarkably — no known receptor or gene. No dosing published here.
Status note: US review status evolving — re-check the July PCAC/Emideltide outcome

Sources:
Schoenenberger GA, Monnier M. Characterization of a delta-electroencephalogram-(sleep)-inducing peptide. Proc Natl Acad Sci USA. 1977; Monnier M, et al. (Original vs synthetic nonapeptide.) Experientia. 1977.
Schneider-Helmert D, Schoenenberger GA. (Human sleep studies, 1980s.)
Bes F, et al. (DSIP in chronic insomnia.) Neuropsychobiology. 1992.
Wikipedia / primary literature on the absent receptor/gene and possible bacterial origin.