Recruiting
Phase 1

Tirzepatide

Sponsor:

National Institute on Alcohol Abuse and Alcoholism (NIAAA)

Code:

NCT07559500

Conditions

Alcohol Use Disorder (AUD)

Eligibility Criteria

Sex: All

Age: 21 - 65

Healthy Volunteers: Not accepted

Interventions

Tirzepatide

Placebo

[11C]raclopride plus drug

[11C]NNC-112

Study Details

Brief summary:

Background:

Glucagon-like peptide 1 (GLP-1) agonist drugs are used to treat diabetes and aid weight loss. They may also help reduce cravings for drugs and alcohol. Researchers want to know if a GLP-1 drug (tirzepatide) can lessen the urge to drink in people with alcohol use disorder (AUD).

Objective:

To learn how the brains of people with AUD respond to a GLP-1 drug.

Eligibility:

People aged 21 to 65 years with AUD who are non-treatment seeking. They must be enrolled in protocol 14-AA-0181. Healthy volunteers are also needed.

Design:

This study consists of Part 1 and Part 2.

Part 1 (Imaging Procedures): Five healthy volunteers will undergo 2 to 3 combined positron emission tomography/magnetic resonance imaging (PET/MRI) scans, with an interval of 2 to 3 weeks between scans. For each scan, a radioactive substance (tracer) will be administered intravenously. Participants will undergo PET/MRI scanning to assess brain activity during resting state. Methylphenidate (Ritalin) will be administered during each scan. Each imaging session will last approximately 2 hours. Tirzepatide and placebo will not be administered in Part 1. Participants with alcohol use disorder (AUD) are not included in Part 1. The purpose of this part of the study is to assess test/retest reproducibility of the PET/MRI combined scan measures.

Part 2 (Randomization to Tirzepatide \& Placebo): Participants will be randomized to receive either Tirzepatide or Placebo first. Healthy Volunteers and AUD participants will receive both treatments in a crossover design. Tirzepatide and placebo will be administered via subcutaneous injection (under the skin) once weekly for 2 to 3 weeks. This treatment period will be followed by 2 to 3 PET/MRI combined imaging scans described in the next paragraph. After a washout interval of approximately 2 to 3 weeks, participants will cross over to the alternate treatment (tirzepatide or placebo), administered once weekly for 2 to 3 weeks. This second treatment period will be followed by an additional 2 to 3 PET/MRI scans. Participants may receive up to 3 doses of tirzepatide and 3 doses of placebo.

Part 2 (Imaging Procedures): Healthy Volunteers and participants with an AUD will undergo PET/MRI scans at two time points: following tirzepatide administration and following placebo administration. For each scan a radioactive substance (tracer) will be administered intravenously. Brain activity will be measured during PET/MRI acquisition during resting state. Methylphenidate will be administered during 1 of the scans at each time point. Each imaging session will last approximately 2 hours. Participants will wear a device to track their activity for at least 1 week before each set of scans. They will have tests of their thinking, memory, and attention.

Conditions

Alcohol Use Disorder (AUD)

Study ID

NCT07559500

Start date

May 20, 2026

Status verified date

Jul 22, 2026

Completion date

Dec 31, 2031

Anticipated

Primary completion date

Dec 31, 2031

Anticipated

Eligibility Criteria

Eligibility Criteria

Sex: All

Age: 21 - 65

Healthy Volunteers: Not accepted

  • INCLUSION CRITERIA:

Healthy Volunteer Participants

To be eligible to participate in this study, an individual must meet the following criteria:

1. Enrollment in 14AA0181.
2. Stated willingness to comply with all study procedures and availability for the duration of the study.
3. Male or female, ages 21-65 years old.
4. Ability to understand and willingness to sign a written informed consent document.
5. Have or had any prior experience with stimulant drugs including cocaine, methylphenidate, amphetamine or methamphetamine, or prescription stimulants (prescription or recreational use), whether or not they have had a past substance use disorder.

AUD Participants

To be eligible, individuals with AUD must meet the following criteria:

1. Enrollment in 14AA0181.
2. Stated willingness to comply with all study procedures and availability for the duration of the study.
3. Male or female, ages 21-65 years old.
4. Ability to understand and willingness to sign a written informed consent document.
5. DSM 5 diagnosis of mild to moderate AUD.
6. Have or had any prior experience with stimulant drugs including cocaine, methylphenidate, amphetamine or methamphetamine, or prescription stimulants (prescription or recreational use), whether or not they have had a past substance use disorder.
7. Minimum 2-year history of heavy drinking (SAMSHA s criteria for heavy drinking: for men 5 or more drinks/day on at least 5 different days per month; and for women 4 or more

drinks/day on at least 5 different days per month.
8. Non treatment seeking AUD participants.

EXCLUSION CRITERIA:

All Participants (Healthy Volunteers and AUD)

1. Presence of ferromagnetic objects in the body that are contraindicated for MRI of the head, fear of enclosed spaces, or other standard contraindication to MRI
2. Cannot lie comfortably flat on his/her back for up to 2 hours in the PET/MRI scanner.
3. BMI <23 or >35 (but no more than 500 lbs). The PET/MRI scanner bed is tested to a weight limit of 500 lbs.
4. Have had previous radiation exposure (from X-rays, PET scans, or other exposure) that, with the exposure from this study, would exceed NIH annual research limits as determined by medical history and physical exam.
5. Pregnant or breast-feeding: Females of childbearing potential, or with tubal ligation, or are post-menopausal and are age 55 or less will undergo a urine pregnancy test and it must be negative to continue participation. Urine pregnancy tests will be repeated on subsequent days of study (i.e., within 24 hours before study procedures). Females must not be currently breastfeeding.
6. Women using oral contraceptives (Part 2 of study). Women of childbearing age who are taking oral contraceptives will be required to switch to a non-oral hormonal contraceptive method (ie implants, injections, or IUDs) or add a barrier method (condoms) for the duration of the study and for 4 weeks after the last dose of study drug after explaining to them that Tirzepatide could make contraceptive less effective. We will not provide nonoral contraceptive medications to participants.
7. Severe head trauma with loss of consciousness > 60 minutes
8. Current severe mental illness (schizophrenia, bipolar disorder).
9. Montgomery-Asberg depression rating scale (MADRS) total score > 35 or suicidal thoughts item score > 3, indicating severe depression or moderate suicidality, respectively.
10. Thyroid cancer or family history of thyroid cancer or personal or family history of multiple endocrine neoplasia syndrome type-2 (MEN-2).
11. History for cerebral aneurysm.
12. Past or present history of chest pain and trouble breathing with activity.
13. History of Heart Disease, Hypertension or Cardiovascular disorders.
14. History of seizures, anxiety, panic attacks, psychosis or glaucoma which are contraindicated with receiving methylphenidate.
15. History of gallbladder disease, pancreatitis, gastroparesis, diabetic retinopathy, acute kidney injury (AKI), as these are contraindicated for Tirzepatide.
16. History of allergic reaction to methylphenidate, Tirzepatide or allergic reactions to dyes or preservatives.
17. Major medical problems that can permanently impact brain function (e.g., seizures, psychosis, stroke, Alzheimer s disease, Parkinson s disease, traumatic brain injury with

loss of consciousness > 30 minutes, clinically significant arrhythmias except bradycardia, and HIV+).
18. Clinically significant laboratory findings that could impact brain function or study procedures (e.g., active infections, significant EKG results, hepatic or renal failure) will be

exclusionary.
19. Current DSM-5 diagnosis of a psychiatric disorder that required daily psychoactive medications (antidepressant, antipsychotics, stimulants, opioids, benzodiazepines or barbiturates) in the past two months and that could impact brain function at the time of the study as determined by history and clinical exam.
20. History of moderate or severe SUD (other than nicotine in HV s, and nicotine, cannabis or alcohol for AUD participants).
21. Daily current use (past 2 months) of the following drugs/medications are exclusionary: stimulant or stimulant-like drugs or medications (cocaine, methamphetamine, amphetamine, methylphenidate, modafinil); opioid drugs or medications; other GLP-1 or anti-diabetic drugs (e.g., insulin, sulfonylureas) medications, antianginal agents; antiarrhythmics; systemic corticosteroids; anticholinergics; anticoagulants; anticonvulsants; antidepressants with dopaminergic effects (bupropion, sertraline, and dopamine agonists like pramipexole and ropinirole); beta-blocker antihypertensives; antineoplastics; antipsychotics; anxiolytics (benzodiazepine or barbiturates); or lithium. Note that alcohol and cannabis use are not exclusionary but participants cannot be intoxicated on the day of study as evidence of alcohol in breathalyzer or cannabis in saliva. Caffeine and nicotine are permitted but participants will be asked to refrain from consuming caffeine or nicotine products (including cigarettes) two hours prior to the study. Antihistamines are also not exclusionary but should not be used on the day of study.
22. \*Non-English speakers (must also be able to read and comprehend English

  • We are excluding non-English speakers since the study includes questionnaires that are validated for English and only some are available in Spanish. The fMRI paradigms also require that the subject be able to speak, read and comprehend English.

Note that subjects will not be excluded from enrollment onto this study if their urine test or breath alcohol level (BAL) is positive for alcohol/drugs on initial screening. The following guidelines will be followed for positive drug/alcohol screens on study procedure days involving imaging scans and neuropsychological testing for all participants:

  • If a subject s breath alcohol (>0.08%) screen test is positive on days involving imaging (PET/MRI) and NP testing, the procedures will be postponed and rescheduled. We will allow for up to 3 rescheduled study days resulting from positive breath alcohol screens. If subject continues to show up intoxicated they will be withdrawn.
  • If urine drug screen is positive for THC-COOH a saliva drug screen will be performed and subject may proceed with study day testing procedures if saliva results for THC are negative. If we are unable to perform the saliva drug screen for any reason, the study day procedures will be postponed. If the urine/saliva drug test is positive on the third rescheduled visit, the participant will be withdrawn from the study. Saliva THC is not required for determining eligibility.
  • If a participants urine drug screen test is positive for cocaine, heroin or methamphetamine after 3 days of rescheduling they will be excluded.

Study Design

Enrollment

176 participants

Anticipated

Allocation

Randomized

Intervention Model

Crossover

Primary purpose

Basic Science

Interventions and Outcome Measures

Arms

placebo comparator: [11C]NNC-112 - Part 2

\[11C\]NNC-112 PET/MR or PET/CT scan obtained without any drug intervention to measure dopamine D1 receptors.

active comparator: [11C]raclopride plus drug - Part 1

Radiotracer injection of \[11C\]raclopride during combined PET/MR scan to measure striatal dopamine release (Methylphenidate 0.25 mg/kg injected 45 minutes post radiotracer injection). Subject is not blind to this drug during scan.

active comparator: [11C]raclopride plus drug - Part 2

Radiotracer injection of \[11C\]raclopride during combined PET/MR scan to measure striatal dopamine release (Methylphenidate 0.25 mg/kg injected 45 minutes post radiotracer injection). Subject is not blind to this drug during scan.

placebo comparator: Placebo - Part 2

1st Dose: placebo will be administered to the abdomen.2nd Dose: placebo will be administered to the abdomen. 3rd Dose (if needed): placebo will be administered to the abdomen.Subject is blinded to drug.

active comparator: Tirzepatide - Part 2

1st Dose: Tirpezatide (2.5 mg dose) will be administered to the abdomen.2nd Dose: Tirzepatide (5 mg dose) will be administered to the abdomen. 3rd Dose (if needed): Tirzepatide (5 mg dose) will be administered to the abdomen.Subject is blinded to drug.

Interventions

Tirzepatide

Drug approved for diabetes administered SQ. Subject is blind to drug.

Placebo

Placebo will be normal saline administered SQ. Subject is blind to drug.

[11C]raclopride plus drug

Radiotracer injection of \[11C\]raclopride during combined PET/MR scan to measure striatal dopamine release (Methylphenidate 0.25 mg/kg injected 45 minutes post radiotracer injection). Subject is not blind to this drug during scan.

[11C]NNC-112

\[11C\]NNC-112 PET/MR or PET/CT scan obtained without any drug intervention to measure dopamine D1 receptors.

Primary outcome measure

  • Part 1 (n=5 healthy volunteers): We will assess the reproducibility of striatal dopamine (DA) measures in response to iv methylphenidate (MP) using PET/MR combined scanning and the bolus infusion protocol in healthy controls. [ Time Frame: We aim to have each subject (n=5) complete all study procedures within 60 days. ]
  • Part 2 (n=88, 44 healthy volunteers and 44 AUD) : Effects of Tirzepatide on striatal dopamine D1R and D2R availability; striatal DA increase; brain reactivity to MP and to food and alcohol cues in AUD and in healthy controls. [ Time Frame: We aim to have each subject complete study procedures within 90 days, but this could take longer. AUD participants will undergo a Follow Up phone call about 1 month after imaging scans are complete. ]

Central Contacts and Locations

Central contacts

Michele-Vera I Yonga, C.R.N.P.

(301) 273-4169michele-vera.yonga@nih.gov

Nora D Volkow Adler, M.D.

(301) 443-6480nvolkow@nida.nih.gov

Locations

National Institutes of Health Clinical Center

Recruiting

Bethesda, Maryland, United States, 20892

Contacts

NIH Clinical Center Office of Patient Recruitment (OPR)

800-411-1222ccopr@nih.gov

More Information

Sponsor

National Institute on Alcohol Abuse and Alcoholism (NIAAA)

Last update posted

Jul 28, 2026

Last verified

Jul 22, 2026

Keywords

  • Tirzepatide
  • Dopamine
  • Alcohol Use Disorder (AUD)
  • Normal Physiology
  • GLP-1

Trial information was received from ClinicalTrials.gov and was last updated on 2026-09-10. This information was provided to ClinicalTrials.gov by National Institute on Alcohol Abuse and Alcoholism (NIAAA) on 2026-07-28.