Scientists believe GLP-1 drugs like Novo Nordisk’s Ozempic help people with obesity lose weight in part because they can help quell food cravings. Intriguing evidence that these drugs may also help people with alcohol use disorder limit drinking has motivated some doctors to try prescribing GLP-1s for those individuals, too.

Controlled clinical trials are now beginning to catch up to clinical practice. A small Phase 2 study published Wednesday in the Journal of the American Medical Association Psychiatry gives some support for this hypothesis. Much of the evidence that has so far been published on alcohol use disorder has relied on animal research or patient records.

The JAMA study, by comparison, randomly assigned people with obesity or who were overweight and also had alcohol use disorder to receive either placebo or a low dose of semaglutide, the active drug contained in Ozempic and Wegovy. Researchers then tested how much the drug changed drinking habits after about two months.

Using a test in which trial volunteers were offered their preferred beverage to drink over two hours, the study found people who received either semaglutide or placebo drank less during the test at the end of the eight-week treatment period than they did at the beginning. Comparatively, though, study participants on semaglutide drank about 50% less than the people given placebo, as measured by breath alcohol concentration and grams of alcohol consumed.

On a weekly basis, semaglutide was associated with a statistical reduction in drinks per drinking day, but not in drinks per calendar day. Treatment didn’t seem to affect the number of drinking days versus abstinent days, but reduced participants’ reported cravings on a questionnaire. 

The trial, which involved just 48 people, isn’t a conclusive verdict on semaglutide’s efficacy in this setting. And the results are far short of what would be needed for the Food and Drug Administration to formally approve the drug’s use in alcohol use disorder. Still, the findings should provide some encouragement to Novo, which has a larger and longer-duration Phase 2 trial testing semaglutide, another obesity drug called cagrilintide and an experimental liver drug on people with alcohol use disorder and liver disease.

Separately, Brigham and Women’s Hospital in Boston is preparing to recruit volunteers to a trial of tirzepatide, a GLP-1 drug sold by Eli Lilly as Zepbound, in alcohol use disorder. Lilly’s CEO also said late last year that his company would begin exploring Zebpound as a treatment for alcohol and drug addiction.

“Reductions in consumption — when considered at large scale — could lead to improved health outcomes that are not currently appreciated,” wrote the study researchers, led by Christian Hendershot, a public health professor at the University of Southern California.

Such large-scale improvements in health outcomes were hinted at in a study assessing more than 200,000 patient records in Sweden. That research found people with alcohol or substance use disorders who took semaglutide or an older Novo GLP-1 drug called liraglutide were significantly less likely to have an alcohol or drug-related hospitalization.

A larger type of data analysis that pools the results of clinical trials and other types of scientific research, called a meta-analysis, has cast some doubt on the hypothesis, however.

The FDA has approved only three drugs to help reduce alcohol consumption: disulfiram in 1951, naltrexone in 1994 and acamprosate in 2004. Lundbeck gained European approval in 2013 for a drug called Selincro that reduced heavy drinking days among people with alcohol dependence. It was never approved in the U.S. for alcohol use disorders, although its active ingredient is approved as a nasal spray and injection to treat opioid overdoses.

Semaglutide is approved as Wegovy for obesity and Ozempic for diabetes, while tirzepatide is marketed as Zepbound for obesity and Mounjaro for diabetes.