Heavy alcohol use can cause atrophy (shown in red) in parts of the brain. Credit: Medical Body Scans/Science Photo Library
The quest for GLP-1 drugs that can treat brain disorders is getting a fresh infusion of energy and funding. Pharmaceutical companies have plunged into developing GLP-1-related compounds to treat addiction, schizophrenia, depression and other conditions — building on years of work by academic scientists.
Last month, pharma giant Eli Lilly presented the first clinical results of brenipatide, a compound related to the company’s blockbuster obesity drug tirzepatide, for treatment of alcohol use disorder. Last week, biotechnology firm Kariya Pharmaceuticals shared early clinical results of a similar compound called KP405 for Parkinson’s disease. And biotechnology company Baseline Therapeutics plans to start a clinical trial in early 2027 of a GLP-1 compound for alcohol use disorder.
Why do obesity drugs seem to treat so many other ailments?
Researchers have long been interested in GLP-1 drugs’ potential against brain conditions. But, until recently, the pharmaceutical industry has not shared that interest, says Lorenzo Leggio, an addiction scientist at the National Institutes of Health in Baltimore, Maryland.
The companies’ new focus on these therapies could accelerate access for people who could benefit from them, says Christian Hendershot, an addiction scientist at the University of Southern California in Los Angeles.
“With the industry trials coming online, we’ll see this area of work grow even more quickly in the next couple of years,” Hendershot says. “Hopefully that will lead to one or more FDA approvals for GLP-1 therapies for addiction.”
Treating the brain
Some of the blockbuster obesity drugs, such as semaglutide, mimic the gut hormone glucagon-like peptide-1 (GLP-1). Others, such as tirzepatide, mimic both GLP-1 and the gut hormone gastric inhibitory polypeptide (GIP). Both hormones are involved in regulating blood-sugar levels, among other functions.
People taking GLP-1 receptor agonists commonly report a lack of interest in drinking alcohol and smoking, an unexpected effect that piqued the interest of addiction researchers. In 2025, Hendershot published the results1 of the first clinical trial of semaglutide in people with alcohol use disorder. The study found that semaglutide reduced the craving for alcohol and episodes of heavy drinking over time. It also lowered the amount of alcohol that participants consumed in a laboratory test.
Since then, two other clinical studies led by academics have found similar results2,3. The studies so far consistently show benefits that seem to be greater than those of the drugs that are currently approved for alcohol use disorder, says Hendershot.
Long half-life
Such results have encouraged pharmaceutical companies to pursue variations of GLP-1 drugs for substance-abuse disorders. One example is brenipatide, the GLP-1 and GIP mimic that Eli Lilly in Indianapolis, Indiana, has been testing for the treatment of alcohol use disorder. The drug remains active in the human body for longer than do approved GLP-1 drugs. According to data presented last month at the Psych Congress in New Orleans, Louisiana, its half-life is 9–12 days, as opposed to 5–7 days for other approved GLP-1 medications. The longer duration makes the drug especially suitable for people living with substance use disorders or psychiatric conditions, says Robert Nicholson, who leads medical affairs for psychiatry and substance use disorders at Eli Lilly.
Could the gut give rise to alcohol addiction?
But, other than the longer half-life, it’s not clear that there are major differences between this compound and the drugs now on the market, says Randy Seeley, an obesity specialist at the University of Michigan in Ann Arbor.
Beyond alcohol use disorder, brenipatide is in clinical trials for a wide range of brain-related conditions, including tobacco and opioid use disorder, depression, schizophrenia and bipolar disorder.
Another GLP-1 mimic aimed at alcohol use disorder is BT-001, which is being developed by Baseline Therapeutics in San Francisco, California. The company plans to start phase III trials of BT-001 in early 2027.