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DSIP (emideltide): why the FDA committee rejected the sleep peptide

Last updated: October 2, 2026 · 4 min read · By the Grey Peptides Editorial Board

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Grey Peptides
Grey Peptides Editorial Board
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Key takeaways
  • DSIP was the only one of seven peptides the FDA's compounding committee voted against in July 2026, by 6 to 7 with one abstention, agreeing with the FDA's own staff.
  • Its sleep evidence is a handful of small trials from the 1980s and 1990s that disagree with each other: one positive seven-night study in insomnia, others judging the effects weak or of little clinical significance.
  • Nearly 50 years after its discovery, no gene, protein or receptor for DSIP has been found, which is why a review called it an unresolved riddle. It is not approved anywhere.

A sleep factor that was never pinned down

Delta sleep-inducing peptide Low, now given the international name emideltide, is nine amino acids long: Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu 1. It was isolated in Basel in 1977 from the venous blood of rabbits' brains as a candidate sleep factor. A 2006 review titled it "a still unresolved riddle": its link to sleep was never properly characterised, partly because no gene, protein precursor or receptor for it has ever been isolated 2. That matters for everything that follows, because without a receptor there is no agreed mechanism to test.

What the sleep trials found

The first human study looked promising. Six healthy volunteers given a slow intravenous infusion in a double-blind crossover reported sleep pressure almost at once, and total sleep over the next two hours rose by a median of 59% against placebo 3. The most positive patient study followed: 14 middle-aged people with chronic insomnia received injections for seven nights under double-blind, placebo-controlled conditions, and their night sleep improved from the first dose 4.

Other trials were less kind. In a crossover study of insomniac patients over four nights, awakenings and waking time fell, but not significantly against placebo, and the authors judged the effect of little clinical significance 5. In 16 chronic insomniacs studied in a sleep laboratory, sleep efficiency was higher and sleep onset faster with DSIP, but the authors called these effects weak and said DSIP was not likely to be useful for treating chronic insomnia 6.

Where the mechanism ideas went

Early work suggested DSIP acted on stress hormones. When this was tested directly in healthy young men, intravenous DSIP left ACTH and cortisol responses almost identical to placebo 7, and in healthy women it had no effect on growth hormone or prolactin 8. In women undergoing surgery, a trial testing whether it would deepen anaesthesia found the opposite of the hypothesis: heart rate rose and anaesthesia seemed lighter 9. And in cats, DSIP reduced sleep, cutting light slow-wave and REM sleep, again the reverse of its name 10.

None of this rules out an effect on sleep in some people. It does mean the mechanism claims made for DSIP online, about stress hormones, growth hormone or deep sleep, have each been tested at least once and not confirmed.

Why the committee said no (as of October 2, 2026)

DSIP was one of seven peptides the FDA's Pharmacy Compounding Advisory Committee considered on July 23 and 24, 2026, for the list of substances pharmacies may compound under section 503A. FDA staff proposed adding none of the seven. The committee recommended six of them anyway, but on emideltide it agreed with the staff and voted it down, 6 to 7 with one abstention 11. Our PCAC page notes the irony that emideltide is the one substance FDA credited with genuine historical use in compounding, and it was still proposed against 11.

A rejection by the committee is advice too. In practice it leaves DSIP where it was: not on the 503A list, not approved anywhere, and sold only as a research chemical. Our PCAC page sets out all seven votes.

Frequently asked questions

Does DSIP help you sleep?

The evidence is mixed and old. One small seven-night trial in insomnia was positive; other small trials found the effects weak or of little clinical significance. No modern trial exists.

Why did the FDA committee reject DSIP?

On July 24, 2026 the compounding committee voted 6 to 7, with one abstention, against adding emideltide to the 503A list, agreeing with FDA staff, who had proposed against all seven peptides reviewed.

What is emideltide?

The international nonproprietary name for delta sleep-inducing peptide (DSIP), a nine-amino-acid peptide first isolated in 1977.

Is DSIP approved?

No. It is not approved anywhere and is not on the FDA's 503A compounding list.

Sources

  1. Grey Peptides dataset, dsip record (sequence and status); read October 2, 2026.
  2. Kovalzon, V. M., et al. (2006). Delta sleep-inducing peptide (DSIP): a still unresolved riddle. J Neurochem, 97(2), 303-9. PMID: 16539679
  3. Schneider-Helmert, D., et al. (1981). Acute and delayed effects of DSIP (delta sleep-inducing peptide) on human sleep behavior. Int J Clin Pharmacol Ther Toxicol, 19(8), 341-5. PMID: 6895513
  4. Schneider-Helmert, D. (1987). Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia. Eur Neurol, 27(2), 120-9. PMID: 3622582
  5. Monti, J. M., et al. (1987). Study of delta sleep-inducing peptide efficacy in improving sleep on short-term administration to chronic insomniacs. Int J Clin Pharmacol Res, 7(2), 105-10. PMID: 3583493
  6. Bes, F., et al. (1992). Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study. Neuropsychobiology, 26(4), 193-7. PMID: 1299794
  7. Späth-Schwalbe, E., et al. (1995). Delta-sleep-inducing peptide does not affect CRH and meal-induced ACTH and cortisol secretion. Psychoneuroendocrinology, 20(3), 231-7. PMID: 7777652
  8. Giusti, M., et al. (1993). Delta sleep-inducing peptide administration does not influence growth hormone and prolactin secretion in normal women. Psychoneuroendocrinology, 18(1), 79-84. PMID: 8475226
  9. Pomfrett, C. J., et al. (2009). Delta sleep-inducing peptide alters bispectral index, the electroencephalogram and heart rate variability when used as an adjunct to isoflurane anaesthesia. Eur J Anaesthesiol, 26(2), 128-34. PMID: 19142086
  10. Sommerfelt, L. (1985). Reduced sleep in cats after intraperitoneal injection of delta-sleep-inducing peptide (DSIP). Neurosci Lett, 58(1), 73-7. PMID: 3840239
  11. US FDA. Pharmacy Compounding Advisory Committee, July 23-24, 2026: briefing documents and votes; status as of September 25, 2026. FDA

Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose.

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