A study found that an obesity drug could prevent not only addiction to alcohol and cigarettes but also to narcotics such as marijuana and cocaine. In particular, it also appeared to reduce the risk of overdose in people already addicted to drugs, potentially preventing hospitalization or death.
A team led by Ziyad Al-Aly, a professor at the Washington University School of Medicine, said in the British Medical Journal (BMJ) on the 4th that an analysis of more than 600,000 U.S. military veterans with type 2 diabetes showed that glucagon-like peptide-1 (GLP-1) therapies reduced the risk associated with all major addictive substances.
Type 2 diabetes occurs when insulin, which regulates blood sugar, is secreted but the body does not use it properly. It mostly affects adults, and patients are often obese or overweight. Type 1, which is more common in children, is a case in which the insulin hormone is not secreted at all.
◇ Survey covered addiction risks from alcohol, tobacco, and drugs
The researchers analyzed the health records of 606,434 veterans with type 2 diabetes. They were already using GLP-1 drugs for diabetes treatment. The team analyzed their health records for up to three years from the time they began receiving the therapy. Participants were divided into groups with and without existing health problems caused by addictive substances such as alcohol, tobacco, and drugs.
The study found that in diabetes patients with no history of drug use, GLP-1 drugs reduced the risk of alcohol-related disorders by 18% compared with those taking sodium-glucose cotransporter-2 (SGLT2) inhibitors, another diabetes treatment. They also lowered the risk of using marijuana (14%), cocaine (20%), nicotine (20%), and opioids (25%). In addition, GLP-1 obesity drugs reduced the risk of overdose (39%), emergency care (31%), and death (50%) among people already using drugs.
GLP-1 is a hormone secreted from the small intestine after meals. It promotes the secretion of insulin from the pancreas to lower blood sugar and suppresses glucagon, which raises blood sugar. It was originally introduced as a diabetes treatment to reduce blood sugar and evolved into an obesity treatment after its weight-loss effect was confirmed. Examples include Wegovy (semaglutide) from Denmark's Novo Nordisk and Mounjaro (tirzepatide) from Eli Lilly and Company. GLP-1 obesity drugs reduce appetite in the brain and slow the rate at which food leaves the stomach, increasing satiety and reducing weight.
In the medical community, there have been repeated reports that diabetes and obesity patients who use GLP-1 therapies experience reduced cravings for alcohol and nicotine. Links have also been repeatedly observed between GLP-1 obesity drugs and reduced risks of drug therapy or alcohol and marijuana use disorders, opioid overdoses, and alcohol-related hospitalizations.
However, previous studies examined addictive substances individually. The researchers said this is the first study to show that GLP-1 drugs can broadly prevent substance addiction and reduce its risks. The veterans tracked in this study were using the GLP-1 diabetes treatments Ozempic (semaglutide) from Novo Nordisk and Saxenda (liraglutide) and Trulicity (dulaglutide) from Eli Lilly and Company.
◇ Clinical trials needed to clarify mechanism of addiction prevention
Kyle Simmons, a pharmacologist at Oklahoma State University, said the reduction in mortality associated with drug use was very surprising and encouraging, adding that a key feature of this study is that it included a GLP-1 treatment group and a control group given other medications.
Simmons said both classes of drugs have positive effects on diabetes and overall health, and that the anti-addiction effect seen in the GLP-1 group supports the hypothesis that the drugs act on the brain rather than reflecting general health benefits. He said it is possible that GLP-1 therapies suppressed brain circuits that use dopamine, a neurotransmitter that reinforces pleasure and triggers craving.
Claire Anderson, president of the Royal Pharmaceutical Society and a professor at the University of Nottingham, also said the study contributes to new research exploring whether GLP-1 drugs can affect brain pathways related to reward and addiction. But she cautioned that GLP-1 obesity drugs' mechanism for preventing or treating drug addiction has not been clarified.
Anderson said that because this was an observational study, it did not prove that the drugs prevent or treat addiction, noting that additional research, including clinical trials, is needed to understand whether GLP-1 drugs have a direct effect.
Marie Spreckley of the Medical Research Council (MRC) Prevention of Diabetes and Metabolic Disorders team at the University of Cambridge said the findings are biologically plausible but should still be considered hypothesis-generating, adding that randomized controlled trials are needed before considering these drugs as treatments for substance use disorders.
References
BMJ (2026), DOI: https://doi.org/10.1136/bmj-2025-086886