GLP-1 drugs draw continued interest in Alzheimer’s despite semaglutide trial setback

GLP-1 drugs used for diabetes and weight loss are being explored as treatments for Alzheimer’s and addiction, even though semaglutide, the active ingredient in Wegovy, recently failed to slow cognitive decline in Alzheimer’s. Studies of electronic health records suggest these drugs could help conditions like addiction, Alzheimer’s, and Long COVID, while a 2025 abstract reported that semaglutide slows the progression of cognitive impairment and pathological changes in the hippocampus in a model of Alzheimer’s disease.

GLP-1 drugs mimic a naturally produced hormone called GLP-1 which regulates hunger, slows digestion, and regulates insulin release. Large diabetes trials showed that the drugs were not only effective at lowering blood sugar but also led to some weight loss, reduced the risk of death, heart attack, and stroke.

Trials show these drugs lead to more weight loss with fewer side effects than other medications. Several are now approved for weight loss, diabetes, sleep apnea, and reducing the risk of other complications. The FDA recently approved Lilly’s once-daily pill Foundayo (orforglipron), making it the first GLP-1 weight loss drug that doesn’t require injections.

The majority of GLP-1 side effects affect the gut. Nausea, vomiting, diarrhea and constipation are common especially as the body is adjusting to higher doses of the drug, and in clinical trials, less than five percent of patients had to stop the drug outright because the side effects were intolerable.

The rapid weight loss from GLP-1s can cause gallbladder problems and muscle mass loss called sarcopenia. In mice, these drugs increase the risk of thyroid cancer but the drugs do not show the same pattern in humans, and a very small number of people might develop a rare eye condition called diabetic retinopathy.

Some people report losing their cravings for alcohol, food, and impulsive behaviors like gambling after starting GLP-1s for weight loss or diabetes, although the data is not there yet to say whether these effects are caused by these drugs. Researchers are still holding out hope, and other drug companies are eager to run more clinical trials combining semaglutide with other treatments.