DSIP (delta sleep-inducing peptide, emideltide): structure, history and US status

DSIP, delta sleep-inducing peptide, is a nine-residue peptide, H-Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu-OH (WAGGDASGE), with the formula C35H48N10O15 and a molecular weight of 848.8. Its international nonproprietary name (INN) is emideltide. G. A. Schoenenberger and M. Monnier reported its isolation from rabbits, and its sequence, in 1977. As of November 7, 2026 no drug containing it is approved in the United States, it is not on the 503A bulks list, FDA staff proposed in July 2026 that it not be added, and it is not one of the six peptides in HHS's interim compounding policy of October 30, 2026. The DSIP sold here is research material, not an approved drug; ours is sold for laboratory research use only.

Where the peptide came from

It grew out of a series of papers by Monnier, Schoenenberger and colleagues titled "Humoral transmission of sleep." The ninth, in 1975, described a "sleep factor delta" in dialysates of rabbit blood as an oligopeptide with a molecular weight of approximately 860. In March 1977, in PNAS, Schoenenberger and Monnier reported the peptide isolated from rabbits, gave its sequence, named it and synthesized it; an Experientia paper the next month compared "the original and synthetic nonapeptide." Their 1978 paper gives the source: dialysate of cerebral venous blood from rabbits during electrical stimulation of the intralaminar thalamus.

The name records what the discoverers reported from those rabbit experiments. It is a 1977 label, not a demonstrated property of the molecule, and this page makes no claim about it.

UniProt files the peptide as entry P01158, from the rabbit, with evidence at protein level from direct protein sequencing; the entry names no gene. One naming trap: UniProt lists "delta sleep-inducing peptide immunoreactor" as an alternative name for TSC22D3 (Q99576), a different, 134-residue human protein whose sequence does not contain WAGGDASGE.

The structure

Read from the N-terminus: tryptophan, alanine, glycine, glycine, aspartic acid, alanine, serine, glycine, glutamic acid, all L except the achiral glycines. Tryptophan is the only aromatic residue, and there is no cysteine, methionine, lysine, arginine or histidine. The only basic group is the free N-terminal amine, against three acidic groups (two side chains and the free C-terminal carboxyl), so by our calculation the net charge at neutral pH is about minus two. Building the formula from the sequence gives C35H48N10O15, matching PubChem and WHO.

WHO's chemical name specifies "L-α-aspartyl" at position 5, and the 1978 paper compares the alpha-aspartyl peptide with its beta-aspartyl isomer, in which the chain continues through the aspartate side chain. The two isomers share one formula, so they share one mass.

One molecule, several names

WHO published emideltide as a proposed INN in List 70 (WHO Drug Information, 1993) and a recommended INN in List 34 (1994); both lists say inclusion "does not imply any recommendation of the use of the substance in medicine or pharmacy." FDA's briefing notes that it is not a United States Adopted Name. One FDA meeting slide calls it "a common name and not a USAN, INN, or IUPAC name"; WHO's two lists show it is an INN, and the briefing itself cites List 70.

US status as of November 7, 2026

FDA's Category 2 text for emideltide, still on its page, cites a possible risk of immunogenicity for certain routes and complexities with peptide-related impurities and characterization. After the nominations were withdrawn, FDA evaluated the free base and the acetate at its own discretion for its Pharmacy Compounding Advisory Committee on July 24, 2026. Its briefing found both "not well-characterized" physically and chemically, and its recommendation reads: "FDA is proposing that emideltide (free base) and emideltide acetate NOT be included on the 503A Bulks List." FDA's meeting page, content current August 6, 2026, posts no vote record; press tallies are in Category 1, Category 2 and the 503A bulks list. A Federal Register search for "emideltide" finds only the April 16, 2026 meeting notice (91 FR 20465), and no proposed rule. FDA's 503B category list does not name it either.

The policy HHS announced on October 30, 2026 names six peptides in its Appendix A: BPC-157, epitalon, KPV, MOTS-c, Semax and TB-500. DSIP, reviewed at the same July meeting, is not among them. None of this concerns research material, which is not for human or veterinary use. Our status table keeps DSIP alongside the other reviewed peptides.

What a certificate for research DSIP should show

FDA's briefing describes what the nominators' certificates lacked. One gave a molecular formula that "does not correspond to any emideltide structure." Another nomination gave the free base's CAS number and formula while its certificate's chemical name and acetic acid test pointed to the acetate. Neither showed impurity limits or an endotoxin test. A useful certificate covers each point:

• The form. FDA gives the acetate's weight as "848.8 plus x60 g/mol." The counter-ion changes the powder's weight, not the peptide; see TFA salt or acetate salt.
• The mass. By electrospray, the monoisotopic mass of 848.33 appears as m/z 849.34 with one proton, 425.17 with two, or 847.32 in negative mode (our calculations). The 848.8 figure is the average weight; mass spectrometry identity explains the difference.
• Purity, with its method. Reversed-phase HPLC, wavelength stated. A mass match cannot exclude the beta-aspartyl isomer, so mass identity and HPLC purity answer different questions.
• Lot, laboratory and date, checkable with the laboratory; see how to verify a lab report.

What our certificate shows

Our 5 mg DSIP has a current certificate from Bioviridian Inc., the testing laboratory: COA7602, lot DSIP-5-0803, issued August 28, 2026. It reports 99.72% purity by reversed-phase HPLC at 214 nm, identity by LC-MS/MS as conforming, a measured content of 5.21 mg, endotoxin <0.05 EU/ml, heavy metals <0.01 ppm and sterility not detected. An earlier lot, DSIP-5-0528, is kept as an archived certificate: 99.9% purity, identity by MALDI-MS, issued June 17, 2026.

DSIP is also one of four listed components of our sleep research blend spray, with pinealon, melatonin and GABA. No certificate is published for that spray, so nothing here is a testing claim about it.

Common questions

Is DSIP the same as emideltide?

Yes. Emideltide is its INN; PubChem lists both names for CID 68816.

Is DSIP FDA approved?

No. Drugs@FDA lists no product containing it (checked November 7, 2026), and FDA's July 2026 briefing says it is not a component of any FDA-approved drug.

Sources

• PubChem CID 68816
• UniProt P01158 and Q99576
• Schoenenberger and Monnier, PNAS, 1977
• Monnier et al., Experientia, 1977
• Schoenenberger et al., Pflugers Arch, 1978
• Monnier et al., Pflugers Arch, 1975
• WHO Proposed INN List 70, 1993 and Recommended INN List 34, 1994
• openFDA drugsfda endpoint
• FDA Category 2 page, April 22, 2026 and as archived April 21, 2026
• FDA 503A list, May 14, 2026 and 503B list, March 21, 2025
• FDA briefing document, emideltide and FDA slides, July 24, 2026
• PCAC meeting page, FDA
• Federal Register search, emideltide
• HHS notice, 91 FR 68526 and policy document, archived October 29, 2026