A comprehensive review of glucagon-like peptide-1 receptor agonists as a novel pharmacotherapeutic frontier in substance use disorder — from neurobiology to clinical evidence.
Glucagon-like peptide-1 (GLP-1) receptor agonists — the drug class behind household names like semaglutide (Ozempic®, Wegovy®) and tirzepatide (Mounjaro®) — were originally developed to treat type 2 diabetes and obesity. Yet clinicians began noticing something unexpected: patients reported not just losing weight, but losing their cravings for alcohol, opioids, nicotine, and even behavioral addictions like gambling.
This observation has ignited one of the most active research fronts in addiction medicine. As of early 2026, over 15 clinical trials are underway globally, NIH-funded studies are accelerating, and a landmark JAMA Psychiatry randomized controlled trial of semaglutide in alcohol use disorder has already demonstrated statistically significant reductions in drinking behavior.
The scientific rationale is compelling. GLP-1 receptors are expressed not only in pancreatic beta cells and the gut, but within key brain reward structures — the ventral tegmental area (VTA), nucleus accumbens, prefrontal cortex, and amygdala — that are central to all addiction neurobiology. By targeting these same circuits that mediate dopamine release and reward salience, GLP-1 drugs may be doing in the addiction domain what they have done in metabolic disease: addressing a root neurobiological driver.
"These molecules demonstrate exciting early promise in stemming the rising tide of addictive disorders."
— Dr. Anna Lembke, Stanford Medicine Psychiatry, 2025The addiction-modulatory effects of GLP-1 receptor agonists operate through several intersecting neurobiological pathways. Unlike classical addiction pharmacotherapies (methadone, naltrexone, buprenorphine) which target opioid or GABA receptors directly, GLP-1 agonists act upstream — modulating the mesolimbic dopamine system that underlies reward anticipation and craving across all addictive substances and behaviors.
GLP-1 receptors are expressed on dopaminergic neurons in the ventral tegmental area (VTA). Activation dampens dopamine release into the nucleus accumbens — reducing the acute reward ("high") associated with substance use and diminishing motivational salience of drug cues.
Direct GLP-1 receptor activation within the nucleus accumbens (NAc) shell modulates GABA and glutamate neurotransmission. Preclinical studies show reduced cue-induced reinstatement of drug-seeking behavior, suggesting GLP-1 can attenuate relapse triggers.
GLP-1 receptors in the prefrontal cortex influence executive function, decision-making, and impulse control — cognitive domains critically impaired in addiction. Enhanced PFC signaling may restore inhibitory control over drug-seeking behavior.
Emerging 2025 preclinical data shows GLP-1 agonists reduce neuroinflammatory cascades implicated in addiction maintenance. This anti-neuroinflammatory action may synergize with existing pharmacotherapies, representing a novel combination therapy strategy.
Peripheral GLP-1 receptor activation in the vagus nerve transmits satiety signals centrally, indirectly influencing hypothalamic circuits that converge with reward pathways. The gut-brain axis appears to be a secondary route of craving suppression distinct from direct CNS action.
Animal models demonstrate that GLP-1 agonists (notably exenatide and semaglutide) reduce stress-induced reinstatement of alcohol and cocaine seeking — a notoriously difficult therapeutic target. The amygdala, rich in GLP-1 receptors, appears to be a key mediator of this effect.
"GLP-1 receptors are found in the same brain structures tied to the reward system: the ventral tegmental area, nucleus accumbens, prefrontal cortex. By targeting these receptors, the drugs blunt dopamine release and reduce reward signaling — that's the crux of how they may help with cravings."
— Dr. Carolina Haass-Koffler, Associate Professor of Psychiatry, Brown University, 2025GLP-1 receptor agonists have now been studied across a remarkably broad spectrum of addictive substances and behaviors. The quantity and quality of evidence varies by domain — alcohol use disorder currently has the strongest clinical evidence base, while behavioral addictions remain largely at the preclinical and observational stage.
The most robust clinical evidence to date comes from alcohol use disorder (AUD). A landmark 2025 JAMA Psychiatry randomized controlled trial by Hendershot et al. tested once-weekly semaglutide (up to 1.0 mg) in adults with AUD, demonstrating statistically significant reductions in drinking days, heavy drinking episodes, and alcohol craving. Participants with higher baseline BMI showed more pronounced effects. Tirzepatide (a dual GLP-1/GIP agonist) was also shown in early 2026 to reduce alcohol drinking and relapse-like behaviors in rodent models. Observational real-world data shows individuals on GLP-1s had a 50% lower rate of alcohol intoxication compared to those not on the medications.
Three clinical trials have specifically investigated GLP-1 agonists for tobacco use disorder. A randomized pilot trial of exenatide (2.0 mg once weekly) combined with nicotine replacement therapy reported increased smoking abstinence rates and reduced craving scores compared to placebo. Ongoing trials of liraglutide (3.0 mg daily) and dulaglutide (1.5 mg once weekly) are investigating nicotine dependence. Preclinical data robustly demonstrates reduced nicotine self-administration in rodent models. Given that nicotine addiction has limited pharmacological options beyond varenicline, GLP-1 agonists represent an important potential addition.
Despite the high public health burden of opioid use disorder (OUD), this is an area of active but early investigation. A small pilot study found GLP-1 medication reduced opioid cravings by approximately 40% over a three-week period. Real-world data indicate patients on GLP-1 agonists had a 40% lower rate of opioid overdose. Brigham and Women's Hospital (under Dr. Joji Suzuki) is currently running a dedicated clinical trial for opioid use disorder. Importantly, GLP-1 agonists could potentially complement existing MOUD (Medications for OUD) such as buprenorphine — targeting craving via a non-opioid pathway while standard agents manage physical dependence and withdrawal.
Cocaine use disorder has no FDA-approved pharmacotherapy, making GLP-1 agonists particularly relevant. Preclinical rodent studies demonstrate consistent reductions in cocaine self-administration and cue-induced reinstatement following GLP-1 receptor activation. The mechanism likely involves attenuation of cocaine-driven dopamine surges in the nucleus accumbens. A 2024 systematic review (Frontiers in Pharmacology, published Jan 2026) identified this as a key area requiring larger clinical trials, given the theoretical soundness of the mechanism and the near-total absence of approved treatments. Human neuroimaging work exploring GLP-1 effects on cocaine cue reactivity is underway.
Perhaps the most striking anecdotal reports concern behavioral addictions. Clinicians and patients have described GLP-1 drugs "obliterating" cravings for gambling, compulsive sexual behavior, shopping, and food. This aligns with the theoretical framework that all these behaviors tap into the same mesolimbic dopamine reward circuitry that GLP-1 agonists modulate. Food addiction deserves special mention: while not yet a formal DSM-5 diagnosis, GLP-1 users commonly describe the medication turning down "food noise" — intrusive thoughts and cravings for ultra-processed food. Researchers are now designing controlled trials specifically targeting behavioral addictions, though formal clinical evidence remains observational and anecdotal as of early 2026.
The clinical evidence base for GLP-1 agonists in addiction has grown substantially from 2022 to 2026. Key investigations span randomized controlled trials, real-world cohort analyses, and neuroimaging studies illuminating the CNS mechanisms in vivo.
Hendershot et al. (Brigham & Women's / NIDA collaboration) — First major RCT of semaglutide for AUD. Demonstrated statistically significant reductions in drinking days and heavy drinking episodes. Patients with higher baseline BMI showed amplified benefit. Semaglutide doses mirrored approved metabolic indications.
Significant reduction in drinking daysFarokhnia & Leggio (NIDA/NIAAA) — Comprehensive review examining where GLP-1 therapy stands in addiction psychiatry, mapping the neurobiological evidence and identifying gaps. Calls for larger trials with standardized outcome measures and longer follow-up periods to establish durable efficacy.
Defines future research agendaEdvardsson et al. — Demonstrated that tirzepatide (dual GLP-1/GIP agonist) outperforms earlier GLP-1 monotherapy in reducing voluntary alcohol consumption and stress-induced relapse in animal models. These findings support clinical investigation of next-generation dual/triple agonists for AUD.
Dual agonists may be superiorVölker, Prechtl, Bormann & Choi — PRISMA 2020 systematic review of 41 studies (35 preclinical, 6 clinical) covering alcohol, nicotine, cocaine, and opioid use disorders. Identified modulation of mesolimbic dopaminergic signaling as the unifying mechanism. Called for standardized methodology and combination therapy exploration.
41 studies · 4 addiction domainsSrinivasan, Farokhnia, Farinelli, Ferrulli & Leggio — Synthesizes preclinical and clinical investigations showing GLP-1 therapies modulate neurobiological pathways underlying addictive behaviors. Notes that only 25% of people with SUDs received treatment in 2023, underscoring the urgency for new options.
Less than 25% SUD treatment uptakeTwo concurrent active RCTs — one for opioid use disorder and one for alcohol use disorder — are currently running at Brigham and Women's Hospital under Dr. Joji Suzuki's Division of Addiction Psychiatry. These represent the most rigorous ongoing investigations. Preliminary safety and feasibility data are being collected in both arms. Results expected 2026–2027.
Results expected 2026–2027GLP-1 agonists have an established and generally favorable safety profile from years of metabolic use — but specific considerations arise when deploying them in populations with substance use disorders, who may have comorbid liver disease, malnutrition, or be on multiple interacting medications. Key points for prescribers and patients are outlined below.
Non-addictive: GLP-1 agonists do not activate opioid, dopamine, or GABA receptors in a way that creates physical dependence. They carry no known abuse potential and do not trigger a withdrawal syndrome upon discontinuation.
No pancreatitis signal at population level: Despite early theoretical concerns, large meta-analyses (>55,000 patients) find no significant association between GLP-1 agonist use and pancreatitis or pancreatic cancer versus other antidiabetic medications.
Established metabolic safety: Semaglutide and liraglutide carry FDA approval with extensive post-market safety data from millions of patients globally. Cardiovascular outcomes are neutral to beneficial.
Weight neutrality benefit: In substance use disorder populations — where metabolic comorbidities are common — weight reduction and glycemic improvements provide additional health benefits alongside potential anti-addiction effects.
GI side effects: Nausea, vomiting, and gastroparesis are common — particularly in early weeks. In individuals with alcohol use disorder or nutritional deficiencies, GI side effects may exacerbate electrolyte imbalances and require careful monitoring.
Pulmonary aspiration risk: GLP-1-slowed gastric emptying raises aspiration risk during surgical or procedural sedation. Addiction patients requiring procedural care or who are acutely intoxicated need pre-procedure GLP-1 management protocols.
Mental health monitoring: While early data shows GLP-1s do not worsen and may improve mood, formal psychiatric safety monitoring in SUD populations — including suicidality screening — remains a recommended standard given the vulnerable population.
Relapse upon discontinuation: Some patients report that food or substance cravings return when GLP-1 medication is stopped, suggesting potential dependency on pharmacological craving suppression. Long-term treatment duration and discontinuation strategies remain undefined.
The field is moving rapidly. Beyond the seminal semaglutide AUD trial, the pipeline now includes investigations of next-generation GLP-1/GIP dual agonists (tirzepatide), GLP-1/GLP-2 combinations, and centrally-active formulations that may deliver more potent CNS effects with fewer peripheral GI side effects.
Brigham and Women's Hospital's Suzuki Lab is running two simultaneous NIH-funded RCTs — one for OUD, one for AUD — with results expected in 2026–2027. Stanford Medicine has separate investigations underway exploring mechanisms of action via neuroimaging. Brown University's Haass-Koffler lab is conducting reverse translational work validating human observations in animal models of craving, cue reactivity, and impulsivity.
Regulatory considerations remain significant: GLP-1 agonists are not FDA-approved for any addiction indication, limiting insurance coverage. Advocacy groups and researchers are pushing for expedited regulatory review pathways given the urgent public health need.
Derived from Gila monster saliva. Addiction potential not yet recognized.
First meaningful clinical signal in tobacco use disorder. Craving reduction confirmed.
Shen & Suzuki (Brigham) conclude more data needed. Launches major new trials.
Hendershot et al. — significant drinking reduction. Field turns a corner. 15+ trials now active globally.
Dual agonists emerge as next frontier. OUD and cocaine trials actively enrolling. FDA pathway discussions begin.
Potential first formal evidence package for FDA review in addiction indication.
The convergence of metabolic and addiction neurobiology via GLP-1 signaling represents a conceptual shift in how we understand and treat substance use disorders. The implications extend from individual clinical practice to healthcare system design and public health strategy.
Dual GLP-1/GIP agonists (tirzepatide) and emerging triple agonists (GLP-1/GIP/glucagon) show amplified reward-blunting effects in preclinical models. CNS-targeted formulations under development aim to maximize mesolimbic impact while reducing peripheral GI adverse effects — potentially the optimal addiction pharmacology profile.
Evidence that higher-BMI patients show stronger anti-addiction effects from GLP-1 agonists suggests metabolic biomarkers may predict responders. Genetic profiling of GLP-1 receptor variants, dopamine pathway polymorphisms, and gut microbiome composition could identify which patients benefit most — enabling precision addiction medicine.
Anti-neuroinflammatory properties of GLP-1 agonists may synergize with existing MOUD (buprenorphine, naltrexone) in opioid use disorder. Preliminary frameworks for combining GLP-1 therapy with behavioral interventions, motivational interviewing, and contingency management are being developed in 2026 trial protocols.
No GLP-1 agonist holds FDA approval for any addiction indication as of early 2026. Insurance coverage off-label for addiction is limited. The high cost of branded semaglutide and tirzepatide (~$900–1,300/month without coverage) creates equity concerns in populations already experiencing structural disadvantages in accessing care.
The 2026 Frontiers systematic review identified methodological heterogeneity as a critical barrier — different outcome measures, sample characteristics, and follow-up durations prevent meta-analytic synthesis. An international working group is developing harmonized GLP-1 addiction trial standards for 2026 onward.
Less than 25% of people with SUDs received treatment in 2023 (NIDA). GLP-1 agonists — already familiar to prescribers and patients from metabolic care — could dramatically lower the barrier to initiating addiction pharmacotherapy. Integration into primary care metabolic programs may destigmatize treatment-seeking and reach the 75% currently untreated.
"This research is very important because alcohol and drug addiction are major causes of illness and death, yet there are still only a few effective treatment options. Finding new and better treatments is critically important to help people live healthier lives."
— Dr. Lorenzo Leggio, NIDA/NIAAA, National Institutes of Health, 2025