DSIP vs Melatonin: differences, evidence and safety

DSIP vs melatonin: DSIP (delta sleep-inducing peptide) is an unapproved research peptide whose most promising result is a small 1987 placebo-controlled trial in which seven nights of injections brought sleep efficiency in 14 chronic insomniacs up to the level of normal sleepers (Schneider-Helmert, 1987). Melatonin is a pineal hormone with far more evidence: a meta-analysis of 19 trials (n=1,683) found it shortened time to fall asleep by about 7 minutes (Ferracioli-Oda, 2013). DSIP has no FDA approval; melatonin is a US dietary supplement and an EU-authorized medicine for insomnia at 55 and over.

Item	DSIP (emideltide)	Melatonin
US FDA status	Not approved. Withdrawn by nominators from FDA’s Category 2 list; page current as of 2026-04-22 (FDA)	Dietary supplement, regulated less strictly than drugs (NIH NCCIH)
Compounding (503A)	PCAC reviewed it on 2026-07-24; no vote is posted on the FDA meeting page (checked 2026-11-09), any vote is advisory, and FDA has issued no rule (FDA meeting page)	Not on FDA’s Category 2 page (checked 2026-11-09)
Approved elsewhere	None identified in the sources reviewed (2026-11-09)	EU: Circadin, authorized 2007-06-29, insomnia aged 55+ (EMA)
WADA	Not named; falls under S0 non-approved substances. The 2027 List (in force 2027-01-01) names “peptides” in S0 (USADA)	Not named in USADA’s 2027 List summary (checked 2026-11-09)
Strongest evidence	Human RCT (n=16, 1992), weak effect	Meta-analysis of 19 RCTs (n=1,683)
Human trials	About 6 small sleep studies, 1981–1992; 0 registered on ClinicalTrials.gov (searched 2026-11-09)	105 insomnia studies registered on ClinicalTrials.gov (searched 2026-11-09)
Last checked	2026-11-09	2026-11-09

DSIP vs melatonin at a glance

Feature	DSIP	Melatonin
What it is	Nine-amino-acid peptide first isolated from rabbit blood in 1977	Hormone the pineal gland releases at night
Class	Neuropeptide, unlike any known peptide family	Pineal hormone (5-methoxy-N-acetyltryptamine)
Target	No receptor identified	MT1 and MT2 receptors
Main research focus	Chronic insomnia, opioid withdrawal	Insomnia, jet lag
Human evidence	About 6 small sleep studies (n=6 to 16 where reported)	19 RCTs in one meta-analysis; 10 jet-lag trials in a Cochrane review
Approval	None identified	EU medicine (Circadin); US supplement
WADA	S0 (non-approved)	Not named
Routes studied	Intravenous	Oral tablets
Timelines in studies	Hours to 7 nights	Near bedtime (jet lag); short-term use (EU label)
Main safety concerns	No long-term data; unregulated products; immunogenicity risk flagged by FDA	Drowsiness; mislabeled supplements; child poisonings

What is DSIP?

Delta sleep-inducing peptide, also called emideltide, is a peptide that a Basel research group isolated from rabbit cerebral venous blood in 1977 and first considered a natural sleep factor (Kovalzon and Strekalova, 2006). It is a nonapeptide, nine amino acids long (Ouichou, 1992), and its structure differs from every other known peptide family. The Kovalzon review calls the case for DSIP as a sleep factor “extremely poorly documented and still weak.” Human sleep testing ran from 1981 to 1992, by intravenous injection in the studies cited here. Our DSIP vs epitalon vs pinealon comparison ranks it against other sleep peptides.

What is melatonin?

Melatonin is a hormone the pineal gland releases on a circadian rhythm: low during the day, high at night (Liu, 2016). It is not a peptide. In the US it is sold as a dietary supplement, which the FDA regulates less strictly than drugs (NCCIH). In the EU, a 2 mg prolonged-release tablet, Circadin, has been an authorized medicine since 2007 for the short-term treatment of primary insomnia “characterised by poor quality of sleep” in people aged 55 or over (EMA). That makes melatonin the only one of the two with a regulator-reviewed sleep indication in the sources checked.

How they work differently

• DSIP: no gene, precursor protein or receptor has been isolated, and in rabbits and rats some synthetic DSIP analogues promoted slow-wave sleep “but not DSIP itself” [Animal] (Kovalzon, 2006).
  Melatonin: binds two well-characterized G protein-coupled receptors, MT1 and MT2, which synthetic drugs such as ramelteon and tasimelteon also target (Liu, 2016).
• DSIP: in healthy volunteers it produced a feeling of sleep pressure without “sedation in the classic pharmacologic way” [Human, n=6] (Schneider-Helmert, 1981).
  Melatonin: its clearest trial results are in jet lag, a circadian timing problem [systematic review of 10 trials] (Herxheimer, 2002).
• The link between them: in perifused rat pineal glands, DSIP stimulated the synthesis and release of melatonin and serotonin, apparently outside the noradrenergic and opioid pathways [Lab] (Ouichou, 1992). No human study testing this was found (PubMed, searched 2026-11-09).

Evidence head-to-head

Outcome	DSIP best evidence	Melatonin best evidence
Time to fall asleep	Human RCT (n=16): shorter, but weak and possibly a placebo-group artifact (Bes, 1992)	Meta-analysis, 19 RCTs (n=1,683): 7.06 min shorter (Ferracioli-Oda, 2013)
Total sleep time	Human crossover RCT: increase in stage 2 only; no difference from baseline nights (Monti, 1987)	Meta-analysis: 8.25 min longer (Ferracioli-Oda, 2013)
Sleep efficiency / quality	Human RCT (n=14): reached normal-control levels after 7 nights (Schneider-Helmert, 1987)	Human RCT (n=354, ages 55–80): 26% vs 15% responders (Wade, 2007)
Jet lag	No study found	Systematic review, 10 trials: 9 positive, NNT 2 (Herxheimer, 2002)
Opioid withdrawal	Open trial, uncontrolled (Backmund, 1998)	No study cited here
Lasting effect	Open study (n=7): sleep normal in 6 of 7 at 3–7 months (Kaeser, 1984)	Long-term data lacking (NCCIH)

All figures are cross-trial: no study has compared DSIP with melatonin directly, and the DSIP sleep studies are more than 30 years old, small, and half of them come from one lead author. The most encouraging DSIP benefits, better sleep efficiency and a significant rise in daytime alertness and performance, came from Schneider-Helmert’s 1987 trial (Schneider-Helmert, 1987). Other groups did not reproduce them: Monti’s team concluded the improvement was “of little clinical significance” (Monti, 1987), and Bes’s team found only weak effects (Bes, 1992). Melatonin’s average effect is modest too, but it rests on many more trials and people.

Which fits which goal?

Melatonin has more evidence for falling asleep sooner, insomnia after 55 and jet lag. Those are the outcomes with pooled trial data (Ferracioli-Oda, 2013), an EU authorization (EMA) and a Cochrane review (Herxheimer, 2002). The limit is the size of the effect: the American Academy of Sleep Medicine’s 2017 guideline suggests clinicians not use melatonin for sleep-onset or sleep-maintenance insomnia in adults, a weak recommendation (Sateia, 2017), and NIH’s complementary-health center says the evidence is not strong enough to recommend it for chronic insomnia (NCCIH).

DSIP has more evidence only where melatonin has none in the sources cited here: opioid withdrawal, and that rests on one uncontrolled trial (Backmund, 1998). For sleep, its promising results on sleep efficiency and daytime alertness (Schneider-Helmert, 1987) were not matched by later double-blind trials. A clinician is the person to decide what fits an individual sleep problem.

Can DSIP and melatonin be taken together?

People search for DSIP and melatonin together, and for blends that add GABA. The only evidence linking the two is a lab finding: DSIP raised melatonin release from rat pineal glands [Lab] (Ouichou, 1992). None of the human DSIP trials cited on this page gave melatonin or GABA alongside it. No controlled human study of the combination was found on PubMed or ClinicalTrials.gov (searched 2026-11-09), so nothing is known about whether the effects add up, cancel out or raise side-effect risk.

Safety and regulatory status

DSIP, United States. DSIP is not an approved drug. FDA once placed it in Category 2, the list of compounding substances that may present significant safety risks, noting that compounded emideltide “may pose risk for immunogenicity for certain routes of administration”; the nominators later withdrew it (FDA). Immunogenicity means the body may form antibodies against the product. On 2026-07-24 FDA’s Pharmacy Compounding Advisory Committee reviewed DSIP for opioid withdrawal, chronic insomnia and narcolepsy (FDA). FDA has not posted the committee’s vote or minutes on the meeting page (checked 2026-11-09). The vote is advisory; FDA has issued no rule. More on what the vote means is in our explainer on the FDA peptide compounding vote.

DSIP, side effects. The small 1981 studies reported no side effects (Schneider-Helmert, 1981), but they followed six people each over days. No long-term human safety data were found (PubMed, searched 2026-11-09), and with no approved product, purity and content depend on unregulated sellers. Our overview Are peptides safe? covers those risks in general.

Melatonin, United States. As a dietary supplement it is regulated less strictly than drugs. Short-term use “appears to be safe for most people,” long-term safety information is lacking, and mild side effects include headache, dizziness, nausea and sleepiness (NCCIH). Label accuracy is a real problem: in a 2017 analysis of 31 supplements, 71% missed their label claim by more than 10%, lot-to-lot content varied by up to 465%, and 26% contained serotonin (Erland, 2017). US poison centers recorded 260,435 pediatric melatonin ingestions from 2012 to 2021, with the annual number up 530%; five children needed mechanical ventilation and two died (Lelak, 2022).

Melatonin, European Union. The Circadin information lists irritability, restlessness, abnormal dreams, dizziness, migraine and somnolence among reactions seen in 1 to 10 of every 1,000 patients, warns that it can cause drowsiness and advises avoiding alcohol (EMA).

Sport. WADA’s S0 class bans substances “not approved by any government regulatory authority” for human use (USADA). DSIP fits that description, and from 2027-01-01 the List names unapproved “peptides” in S0 explicitly (USADA). Melatonin is not named in USADA’s summary of the 2027 List (USADA), and because it is an EU-authorized medicine, the non-approved S0 class does not describe it.

Anyone who suspects a side effect from DSIP, melatonin or any other drug or product can report it to the FDA through MedWatch.

How long do effects take in studies?

• DSIP: in insomniacs, sleep promotion appeared in the second hour after injection, after a slight arousing effect in the first hour [Human, n=6] (Schneider-Helmert, 1981). Repeated injections showed a buildup, with sleep structure normalizing after four administrations (Schneider-Helmert, 1984). In the 7-night trial, effects held for one placebo night after treatment stopped [Human RCT, n=14] (Schneider-Helmert, 1987).
• Melatonin: in jet-lag trials it worked when taken close to the target bedtime at the destination (Herxheimer, 2002); Circadin is authorized for short-term treatment (EMA).