NEW YORK / LOS ANGELES — Researchers have long known that GLP-1 drugs like Ozempic and Wegovy reduce appetite and help patients lose weight. But a landmark study published in The BMJ this spring has revealed something nobody expected: these same drugs appear to fight addiction itself — across every major addictive substance, from alcohol to cocaine to opioids.

The study, led by clinical epidemiologist Dr. Ziyad Al-Aly of the VA St. Louis Health Care System, analyzed the electronic health records of 606,434 U.S. veterans with type 2 diabetes. It is the largest study of its kind ever conducted.

▶ WHAT THE STUDY FOUND

Veterans taking a GLP-1 medication — most commonly semaglutide, sold as Ozempic or Wegovy — were 14% less likely than those on a different diabetes drug to develop any new substance use disorder related to alcohol, cannabis, cocaine, nicotine, or opioids.

Among veterans who already had a substance use disorder, the findings were even more striking: overdoses dropped by approximately 39%, and deaths linked to substance use — including drug-related overdoses — fell by roughly 50% compared to those not on GLP-1 medications.

"The consistency of effect across multiple substances, which have different mechanisms of action, was quite a revelation," Dr. Al-Aly told reporters after publication.

▶ WHY THIS IS CRUCIAL FOR U.S. CITIES

The U.S. opioid epidemic has devastated communities from Harlem to South Los Angeles to the South Side of Chicago. Houston has seen fentanyl-related deaths triple over the past five years. Philadelphia, one of the hardest-hit cities in the nation, recorded over 1,400 overdose deaths in 2024 alone.

If GLP-1 drugs truly reduce addiction-related hospitalizations and overdoses, the downstream benefits for America's most populated cities — where addiction treatment resources are often overwhelmed — could be enormous.

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▶ HOW THE BRAIN-ADDICTION CONNECTION WORKS

Scientists believe GLP-1 drugs may influence the brain's reward and craving circuits — the same pathways hijacked by addictive substances. Preclinical studies in animals had already shown that GLP-1 receptor activation reduced reward-seeking behavior. The new VA study suggests those effects appear to translate to humans, and across substances with very different mechanisms of action.

A separate small Phase 2 trial of 48 adults with alcohol use disorder found that weekly semaglutide reduced drinking and cravings over nine weeks compared with placebo. More trials are now underway — including a major study at the National Institute on Drug Abuse — expected to provide definitive answers.

▶ EXPERTS URGE CAUTION — BUT SEE REAL PROMISE

Researchers stress that the VA study is observational — it cannot prove the drugs directly prevent addiction. Physician and addiction researcher Lorenzo Leggio of the National Institute on Drug Abuse notes that the finding should not yet replace FDA-approved addiction treatments like naltrexone.

But even the skeptics acknowledge the implications. Ninety-eight percent of Americans with alcohol use disorder currently receive no FDA-approved medication at all. If GLP-1s — drugs already being prescribed to millions — turn out to reduce that gap, the public health payoff could be historic.

For veterans already on Ozempic or Wegovy for diabetes or weight loss, these findings add one more compelling reason to continue treatment. And for the millions of Americans struggling with addiction in the country's largest cities, hope may be arriving in the form of a weekly injection.