DSIP vs Melatonin: How They Differ

DSIP (delta sleep-inducing peptide) is a nine-amino-acid neuropeptide named for the deep, delta-wave sleep it produced in early experiments, while melatonin is not a peptide at all but a small indoleamine hormone from the pineal gland that tells the body’s clock it is night. Melatonin is a timing signal with large modern trials behind it; DSIP is defined by its effects on sleep itself, with a smaller set of human studies from the 1980s. Here is how they differ and what the research on each shows.

Findings

• Melatonin is made in the dark: its production is driven by the brain’s master clock and switched off by light, and it acts as a sleep-anticipating signal (2018 review).
• Across 19 placebo-controlled studies and 1,683 people with primary sleep disorders, melatonin shortened sleep onset by 7.06 minutes, lengthened total sleep by 8.25 minutes and improved sleep quality, with effects that did not fade with continued use (2013).
• In 354 adults aged 55 to 80 with insomnia, prolonged-release melatonin shortened sleep latency by 24.3 minutes against 12.9 on placebo and improved sleep quality and morning alertness (2007).
• In a placebo-controlled, double-blind study of 14 adults with severe chronic insomnia, seven nights of DSIP brought night-time sleep efficiency up to the level of normal controls and raised daytime alertness (1987).

What is DSIP?

DSIP is a nonapeptide isolated and characterised between 1963 and 1977. In the first experiments it induced mostly delta sleep, the deep slow-wave stage, across several species including humans (Graf and Kastin, Peptides, 1986), and early reviews also recorded effects on hormone levels, circadian and activity patterns and drug withdrawal (Graf and Kastin, Neurosci Biobehav Rev, 1984). As of a 2006 review, no DSIP gene or dedicated receptor had been isolated, so it is defined by these effects rather than by a known target (Kovalzon and Strekalova, J Neurochem, 2006).

The human sleep studies

The strongest result is a 1987 placebo-controlled, double-blind study of 14 middle-aged adults with severe chronic insomnia. Seven nights of DSIP improved sleep from the first administration, the effect carried into the next placebo night, sleep efficiency at night reached the level of normal controls, and daytime alertness and performance rose (Schneider-Helmert, Eur Neurol, 1987). A 1986 study of 18 insomniacs aged 29 to 83 found middle-aged participants reached normal sleep values within the week, and older participants, whose sleep was twice as disturbed, normalised by the end of follow-up (Schneider-Helmert, Eur Neurol, 1986). Earlier work reported longer, less interrupted sleep without daytime sedation (Schneider-Helmert and Schoenenberger, Experientia, 1981). Two later double-blind studies from other groups reported smaller effects (Monti et al., 1987; Bes et al., 1992). These studies gave DSIP intravenously and recorded sleep in the laboratory.

What is melatonin?

Melatonin is an indoleamine hormone made by the pineal gland. A central clock in the suprachiasmatic nuclei of the hypothalamus drives its production at night, and light suppresses it; the nightly rise conveys darkness to the body and sets up night-state functions including sleep (Zisapel, Br J Pharmacol, 2018). It is a single small molecule, not a chain of amino acids. Taken by mouth, its bioavailability is poor and variable (Zetner et al., Drug Res, 2016).

What the melatonin trials show

Melatonin has the larger and more recent evidence base. A 2005 meta-analysis of 17 studies (284 participants) found it reduced sleep onset latency by 4.0 minutes, raised sleep efficiency by 2.2% and lengthened total sleep by 12.8 minutes (Brzezinski et al., Sleep Med Rev, 2005). A 2013 meta-analysis of 19 trials in 1,683 people with primary sleep disorders found sleep onset 7.06 minutes faster and total sleep 8.25 minutes longer, with better overall sleep quality; longer trials and higher doses showed larger effects, and the benefit did not fade with continued use (Ferracioli-Oda et al., PLoS One, 2013). The authors described the effects as modest beside other insomnia drugs, with a relatively benign side-effect profile.

Prolonged-release melatonin was tested in primary care in 354 adults aged 55 to 80 with insomnia. Over three weeks, 26% met the responder definition for better sleep quality and morning alertness together, against 15% on placebo, and sleep latency fell by 24.3 minutes against 12.9 (Wade et al., Curr Med Res Opin, 2007). A 2 mg prolonged-release tablet, Circadin, was authorised in the European Union in June 2007 for short-term treatment of primary insomnia in adults aged 55 and over.

Melatonin’s status in Canada

In Canada, melatonin products for adults are licensed as natural health products. Since 2 June 2026, melatonin for sleep-related use in children and adolescents under 18 is on the Prescription Drug List (Health Canada notice of amendment).

How do DSIP and melatonin compare side by side?

Question	DSIP	Melatonin
What is it?	Neuropeptide	Indoleamine hormone from the pineal gland
Size	9 amino acids	Small non-peptide molecule
Main research area	Deep sleep, insomnia, withdrawal	Sleep timing, insomnia, circadian disorders
Mechanism	Defined by its effects; no receptor isolated	Night signal to the circadian clock
Human evidence	Small laboratory studies, 1980s	Meta-analyses of placebo-controlled trials
Regulatory status	Research compound	EU prescription product; natural health product for adults in Canada
Forms we supply	5 mg vial and ready-mixed nasal spray	Not supplied

Which fits which research question?

• Circadian timing, sleep onset and jet-lag type designs: melatonin, the body’s own darkness signal, with the larger trial record.
• Sleep depth, slow-wave sleep and sleep efficiency in severe insomnia: DSIP, whose human studies recorded sleep architecture in the laboratory and tracked next-day function.
• Withdrawal states: DSIP, which has human alcohol and opiate withdrawal data (Dick et al., Eur Neurol, 1984).

No study comparing them directly was found, so the figures above come from different populations and methods. DSIP is compared with an anxiety peptide in DSIP vs Selank and with a pineal peptide in Epitalon vs DSIP.

How is DSIP supplied?

Vistara Labs supplies DSIP as a 5 mg lyophilised vial and as a ready-mixed DSIP Nasal Spray delivering 0.175 mL per press; the spray is also part of the Sleep & Calm Spray Stack. The human studies above used intravenous administration. Vials are reconstituted with bacteriostatic water (see the DSIP reconstitution guide). Certificates of analysis are on the lab reports page, buying details are in Buy DSIP in Canada, and every order ships from within Canada. Vistara Labs does not supply melatonin.

Frequently asked questions

What is the difference between DSIP and melatonin?

DSIP is a nine-amino-acid neuropeptide studied for deep, delta-wave sleep, with no receptor yet isolated. Melatonin is a small non-peptide hormone from the pineal gland that signals night to the body’s circadian clock.

Is DSIP stronger than melatonin?

They have not been compared directly. DSIP’s strongest study brought sleep efficiency to normal levels in 14 adults with severe insomnia; melatonin’s meta-analyses cover far more people and show consistent, modest gains in sleep onset, duration and quality.

Is melatonin a peptide?

No. Melatonin is an indoleamine, a single small molecule made by the pineal gland. DSIP is a peptide, a chain of nine amino acids.

Can DSIP and melatonin be studied together?

No published human research on the combination was found. Both are studied against sleep outcomes such as onset and efficiency, so in one design their effects would be hard to separate.

Where can I buy DSIP in Canada?

Vistara Labs supplies DSIP as a 5 mg lyophilised vial and a ready-mixed nasal spray for laboratory research, shipped from within Canada by Canada Post Xpresspost.

Product details from vistaralabs.ca, October 2026. Sources: Graf MV, Kastin AJ. Delta-sleep-inducing peptide (DSIP): a review. Neurosci Biobehav Rev. 1984. PMID 6145137. Graf MV, Kastin AJ. Delta-sleep-inducing peptide (DSIP): an update. Peptides. 1986. PMID 3550726. Kovalzon VM, Strekalova TV. Delta sleep-inducing peptide (DSIP): a still unresolved riddle. J Neurochem. 2006. PMID 16539679. Schneider-Helmert D. Effects of delta-sleep-inducing peptide on 24-hour sleep-wake behaviour in severe chronic insomnia. Eur Neurol. 1987. PMID 3622582. Schneider-Helmert D. Efficacy of DSIP to normalize sleep in middle-aged and elderly chronic insomniacs. Eur Neurol. 1986. PMID 3792404. Schneider-Helmert D, Schoenenberger GA. The influence of synthetic DSIP (delta-sleep-inducing-peptide) on disturbed human sleep. Experientia. 1981. PMID 7028502. Monti JM et al. Study of delta sleep-inducing peptide efficacy in improving sleep on short-term administration to chronic insomniacs. Int J Clin Pharmacol Res. 1987. PMID 3583493. Bes F et al. Effects of delta sleep-inducing peptide on sleep of chronic insomniac patients. A double-blind study. Neuropsychobiology. 1992. PMID 1299794. Dick P et al. DSIP in the treatment of withdrawal syndromes from alcohol and opiates. Eur Neurol. 1984. PMID 6548969. Zisapel N. New perspectives on the role of melatonin in human sleep, circadian rhythms and their regulation. Br J Pharmacol. 2018. PMID 29318587. Zetner D et al. Pharmacokinetics of alternative administration routes of melatonin: a systematic review. Drug Res. 2016. PMID 26514093. Brzezinski A et al. Effects of exogenous melatonin on sleep: a meta-analysis. Sleep Med Rev. 2005. PMID 15649737. Ferracioli-Oda E et al. Meta-analysis: melatonin for the treatment of primary sleep disorders. PLoS One. 2013. PMID 23691095. Wade AG et al. Efficacy of prolonged release melatonin in insomnia patients aged 55-80 years: quality of sleep and next-day alertness outcomes. Curr Med Res Opin. 2007. PMID 17875243. European Medicines Agency, Circadin product information (authorised 29 June 2007). Health Canada, notice of amendment to the Prescription Drug List qualifier for pediatric melatonin use.

More on this: Peptides for Sleep: What the Research Shows.