Emideltide
Delta sleep-inducing peptide · Also called DSIP
- UK status
- Unlicensed medicine
- Availability
- Research use only
- Evidence base
- Human trials exist and contradict each other
- Controlled drug
- No
Peptide sequence, one-letter notation
WAGGDASGE
The short version
What it does
Sold for insomnia, and also promoted for opioid withdrawal and narcolepsy.
How it does it
A peptide found in the brain that was originally identified because it seemed to bring on deep sleep in animals. The idea is that giving more of it helps you sleep.
The catch
This is the one the FDA's advisory committee rejected, in a meeting where it approved everything else. Published human trials on insomnia reached contradictory conclusions.
Everything below goes into the detail, with sources.
Emideltide is worth a record for one reason: in a two-day meeting where an FDA advisory committee waved through six peptides against its own scientists' advice, this was the only one it voted down.
01What it is
Delta sleep-inducing peptide was identified in the 1970s in work on rabbits, where a substance from the blood of sleeping animals appeared to induce delta-wave sleep, the deep stage, when given to others. It is nine amino acids long.
The name describes what it was hoped to do, which is worth noting. A great many compounds are named for their hoped-for effect rather than a demonstrated one.
02How it came about
DSIP has been studied on and off since the 1970s, with human work on chronic insomnia, pain conditions and opioid withdrawal. It never reached approval anywhere.
It was nominated for the FDA's 503A compounding list for sleep and reviewed on the second day of the July 2026 advisory committee meeting, where it was the only one of the seven compounds to receive a negative vote.
03UK legal and licensing status
No MHRA authorisation and no approval anywhere. Supplying it for human use in the UK without authorisation is prohibited. Not a controlled drug.
The July 2026 advisory committee voted against recommending it for US compounding, which is the clearest negative regulatory signal any compound in this register has received recently.
04How it works
The proposed mechanism is poorly characterised even by the standards of this group. It has been described as acting on sleep regulation centrally, with reported effects on stress hormones and on pain signalling. The FDA described the mechanism as plausible, which is a long way from established.
05What it is not
Claims that attach themselves to this compound and do not hold up.
- Not an approved sleep treatment anywhere.
- Not supported by consistent human evidence. Published trials on chronic insomnia reached contradictory conclusions, with researchers disagreeing.
- Not endorsed by the July 2026 vote. It was rejected, and it is the only one that was.
06What the evidence shows
Unusually for this group, human trials do exist. The problem is what they say.
The FDA's review found that published trials on chronic insomnia reached contradictory conclusions. When studies of the same compound for the same condition disagree, the most likely explanation is that any real effect is small enough to be swamped by differences in trial design, population and chance. That is a different situation from no evidence, and it is not a more encouraging one.
There are licensed treatments and, more importantly, non-drug approaches with strong evidence for chronic insomnia. Cognitive behavioural therapy for insomnia outperforms most sleep drugs in trials and is recommended first line.
Whether there is any consistent effect at all, at what dose, and with what long-term safety. The contradictory trial record is the central problem, not a side issue.
07Reported harms
No regulated frequency table. Reported tolerability across the older human studies was generally unremarkable, from small and inconsistent trials.
Standard unregulated supply risks apply. The FDA raised immunogenicity and impurity concerns across this whole group.
08Interactions and cautions
Unknown. Anyone taking sleep medication, sedatives or opioids is combining things acting on overlapping systems with no guidance whatsoever.
09Stopping
Undocumented.
10Monitoring
Nothing formal exists.
11Questions worth asking
Take these to a doctor or pharmacist. A good clinician will not mind being asked, and the answers are specific to you in a way nothing on this page can be.
- Have I tried cognitive behavioural therapy for insomnia, which has better evidence than most sleep drugs?
- Is there something treatable causing the insomnia, such as sleep apnoea, that nobody has looked for?
- Given trials on this contradict each other, what am I expecting?
12Common questions
Does DSIP help you sleep?
The human evidence is contradictory. Published trials on chronic insomnia reached conflicting conclusions, which usually means any real effect is small. The FDA's advisory committee voted against recommending it in July 2026.
Why was it the only one rejected?
The committee gave a negative vote where it had approved the other six compounds. The FDA's review had noted the contradictory human trial record, and there are approved alternatives for insomnia.
What actually works for chronic insomnia?
Cognitive behavioural therapy for insomnia has the strongest evidence and is recommended first line, ahead of medication, in UK guidance. Your GP can refer you, and there are NHS-approved digital programmes.
13Sources
Links go to the authoritative source. Where a document sits behind a paywall or moves around, the full citation is given so you can find it yourself.
- Bulk drug substances review, emideltideFDA
- PCAC July 2026 meeting materialsFDA
- DSIP clinical literaturePubMed
- Insomnia guidanceNICE
- Unlicensed medicines guidanceMHRA
14Change history
Every substantive change to this record is logged here with its date. Corrections are made openly, not quietly.
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