Oxytocin Nasal Spray for Reducing Cravings and Preventing Relapse in Adults with Substance Use Disorder

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What is this study about?

A condition called substance use disorder is a health problem in which a person continues to use drugs such as heroin or cocaine despite negative effects. The study tests a medication called oxytocin, which is given as a nasal spray, and compares it with a control spray that does not contain the active drug (placebo). The goal is to see whether oxytocin can lower the strong desire to use drugs (craving) and help prevent a return to drug use (relapse).

Participants receive the spray once daily for four weeks. At the start and after 30 days, they undergo a brain scan called fMRI, which shows how certain brain areas are active. They also report their cravings at the beginning, after one week, and after four weeks, and their drug use is checked again at three and six months after the treatment period. The study looks at changes in cravings, brain activity, and how long participants stay away from drugs.

1 baseline assessment and randomization

on the first day after joining, a complete assessment is performed. this includes a self‑report questionnaire about drug craving, a brain imaging scan (functional magnetic resonance imaging, fmri) to measure activity in specific brain regions, and collection of medical information.

based on the assessment, the participant is randomly assigned to receive either the oxytocin nasal spray (product name: syntocinon 40 iu/ml nasal spray) or the placebo nasal spray (ialu clenny nasal spray).

2 first dose administration

the assigned nasal spray is used under supervision. each dose contains 40 international units (iu) of oxytocin for the active group; the placebo contains no active drug.

the spray is administered intranasally, typically one spray in each nostril. the exact schedule is defined by the study protocol.

3 daily dosing period (days 2‑30)

the participant continues to use the assigned nasal spray once daily for a total of 30 days.

the dose remains 40 iu per administration for the active group; the placebo group uses an identical‑appearing spray without active ingredient.

participants are instructed to keep a diary of each dose and report any adverse symptoms to the study staff.

4 first follow‑up assessment (day 7)

after one week of treatment, a follow‑up visit is conducted.

the same self‑report craving questionnaire is completed, and additional cognitive tasks may be performed.

no brain imaging is performed at this visit.

5 second follow‑up assessment (day 30)

at the end of the 30‑day treatment period, a second follow‑up visit occurs.

the participant repeats the self‑report craving questionnaire and undergoes a second fmri scan to compare brain activity with the baseline scan.

all study medication is discontinued after this visit.

6 long‑term follow‑up for abstinence (3‑month and 6‑month)

three months after the end of treatment, the participant returns for a follow‑up visit to assess duration of abstinence. drug use is evaluated by questionnaire and, if required, biological testing.

a similar visit is scheduled at six months for the same purpose.

Who Can Join the Study?

Primary diagnosis of substance use disorder – you must have been officially diagnosed with a problem using drugs such as heroin or cocaine, based on the standard DSM‑V guidelines (a book doctors use to define mental health conditions).
Age and gender – you must be a man, or a woman who is not currently pregnant or breastfeeding, and be between 18 and 55 years old.
Willing and able to give informed consent – you must understand the study and agree to take part, signing a form that shows you know what will happen.
Understanding of Italian – you need to be able to read and speak Italian well enough to follow the study instructions.
Provide an identity document – you must show a valid ID (like a passport or driver’s license) to confirm your identity.

Who Cannot Join the Study?

Having a major psychiatric disorder, such as schizophrenia (a condition that can cause loss of touch with reality), severe psychosis, bipolar disorder (extreme mood swings), severe depression with thoughts of suicide, antisocial personality disorder (disregard for others), or currently active anxiety disorders.
Being pregnant, planning to become pregnant, or currently breastfeeding (lactating).
Having a serious medical problem that could affect safety, such as cardiovascular disease (heart disease, heart attacks, or very high blood pressure), kidney disease, thyroid disease (issues with the gland that controls metabolism), epilepsy (seizure disorder), or a significant brain injury (brain trauma).
Having any serious nasal cavity pathology, for example chronic inflammation of the nose lining, previous removal of the pituitary gland (hypophysectomy), frequent nosebleeds, or a hole in the nasal septum.
Having an alcohol use disorder (problematic drinking) while currently receiving medication for it.
Any other health condition that the study doctor believes would make participation unsafe.

Where you can join this trial?

Verified and Recommended Sites

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Verified Sites

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Other Sites

Site Name	City	Country	Status
Fondazione Santa Lucia	Rome	Italy

Trial status

Country	Status	Recruitment Start
Italy	Not yet recruiting	01.05.2026

Trial locations

Investigated drugs:

Oxytocin

Syntocinon is a nasal spray that contains oxytocin, a hormone that supports social bonding and feelings of trust. In the trial, participants use the spray in their nose. Researchers are testing whether this medication can lower the intense urge (craving) for drugs such as heroin or cocaine and help prevent people who have stopped using from starting again.

Investigated diseases:

Substance use disorder

Substance Use Disorder – It is a condition in which a person repeatedly uses a drug such as heroin or cocaine even when it causes problems in daily life. The pattern usually starts with occasional use and can grow into more regular use as the person seeks the drug’s effects. Over time, the desire to use the drug becomes stronger and the person may find it hard to stop or cut back. Cravings can appear when the person encounters reminders of the drug or experiences stress. The disorder often leads to changes in how the person thinks, feels, and behaves, making it harder to focus on other activities. As use continues, the need for the drug can dominate the person’s routine.

Trial ID:

2023-504518-31-01

Trial Phase:

Therapeutic exploratory (Phase II)

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