GLP-1 Drugs Move Into Clinical Trials for Addiction, Depression and Brain Diseases
Consuming large amounts of alcohol can cause atrophy, shown in red, in parts of the brain.
Credit: Medical Body Scans/Science Photo Library
The search for GLP-1 drugs that can treat brain diseases is gaining new momentum and funding. Building on years of academic research, pharmaceutical companies are developing GLP-1-related compounds for addiction, schizophrenia, depression and other conditions.
Last month, pharmaceutical giant Eli Lilly announced the first clinical results for brenipatide, a compound related to its blockbuster obesity drug tirzepatide, as a treatment for alcohol use disorder. Last week, biotechnology company Kariya Pharmaceuticals announced early clinical results for KP405, a similar compound being studied for Parkinson’s disease. Baseline Therapeutics also plans to begin clinical trials of a GLP-1 compound for alcohol use disorder in early 2027.
Why do obesity drugs seem to be effective against many other diseases?
Researchers have long been interested in the potential of GLP-1 drugs for brain diseases. Until recently, however, the pharmaceutical industry did not share that interest, says Lorenzo Reggio, an addiction scientist at the National Institutes of Health in Baltimore, Maryland.
Christian Hendershot, an addiction scientist at the University of Southern California in Los Angeles, says the companies’ growing focus on these treatments could accelerate access for people who might benefit from them.
“Jobs in this field will grow even more rapidly in the coming years as industry trials move online,” Hendershot says. “We hope it will lead to FDA approval of GLP-1 therapy for addiction.”
How GLP-1 drugs could treat addiction
Some obesity drugs, including semaglutide, mimic the intestinal hormone glucagon-like peptide-1 (GLP-1). Others, such as tirzepatide, mimic both GLP-1 and the intestinal hormone gastric inhibitory polypeptide (GIP). Both hormones help regulate blood sugar levels, among other functions.
People taking GLP-1 receptor agonists commonly report losing interest in drinking or smoking. This unexpected effect has attracted the attention of addiction researchers.
In 2025, Hendershot announced results from the first clinical trial of semaglutide in people with alcohol use disorder1. The study found that semaglutide reduced alcohol cravings and binge-drinking episodes over time. It also reduced the amount of alcohol consumed by participants during clinical tests.
Since then, two other academic clinical studies have reported similar findings.2,3 Hendershot says previous studies have consistently suggested that the drug could be more effective than currently approved treatments for alcohol use disorder.
Brenipatide has a longer half-life than existing GLP-1 drugs
These results have prompted pharmaceutical companies to pursue variations of GLP-1 drugs for substance use disorders. One example is brenipatide, a GLP-1 and GIP mimetic being tested by Eli Lilly and Company of Indianapolis, Indiana, for alcohol use disorder.
Brenipatide remains active in the human body longer than approved GLP-1 drugs. According to data presented at a psychology conference last month in New Orleans, Louisiana, the drug has a half-life of 9 to 12 days, compared with 5 to 7 days for other approved GLP-1 treatments.
Robert Nicholson, Eli Lilly’s head of medical affairs for psychiatry and substance use disorders, says the drug’s longer duration could make it particularly suitable for people with substance use disorders and mental illness.
Can the gut cause alcoholism?
Randy Seeley, an obesity expert at the University of Michigan in Ann Arbor, says it is not clear whether brenipatide differs substantially from drugs already on the market apart from its longer half-life.
Beyond alcohol use disorder, brenipatide is being studied in clinical trials for a range of brain-related conditions, including tobacco and opioid use disorders, depression, schizophrenia and bipolar disorder.
Other GLP-1 compounds in development
BT-001 is another GLP-1 mimic being developed for alcohol use disorder. Baseline Therapeutics of San Francisco, California, plans to begin Phase III trials of BT-001 in early 2027.
Source: www.nature.com