Thinking About A GLP-1 Drug? Your Genetics Might Determine How Well You'll Fare

MONDAY, April 13, 2026 (HealthDay News) — Your genetics might play a role in how well cutting-edge weight loss drugs like Ozempic and Zepbound will work for you, a new study says.

Specific genetic traits can affect both weight loss and side effects for people taking GLP-1 drugs like semaglutide (Ozempic/Wegovy) and tirzepatide (Mounjaro/Zepbound), researchers reported April 8 in the journal Nature.

“While there is high interest in GLP-1 medications, there is significant variation in how well they work for different people,” researcher Dr. Noura Abul-Husn, chief medical officer at the 23andMe Research Institute, said in a news release.

“The market is crowded with weight loss support and medications, but the approach to weight management is typically one of trial and error,” she said. “This can lead people to leap into treatment with a high degree of uncertainty and unrealistic expectations about efficacy and possible side effects.”

Glucagon-like peptide-1 (GLP-1) drugs mimic the GLP-1 hormone, which helps control insulin and blood sugar levels, decreases appetite and slows digestion of food.

While the drugs are effective, their potency varies from person to person, researchers said. Some people lose less than 5% of their body weight, while others drop more than 20%.

The same goes for side effects. Some people suffer problems like nausea and vomiting while taking a GLP-1 drug, and others don’t.

For the new study, researchers leveraged genetic data maintained by 23andMe, a DNA testing service aimed at providing consumers information about their ancestry and health.

Researchers used data from nearly 28,000 people using GLP-1 medications to look for variations in the genes targeted by the drugs.

Results showed that a small alteration in the GLP1R gene plays a role in how well the drugs will work in individuals.

Researchers also found that differences in two genes, GLP1R and GIPR, affect risk of nausea and vomiting. However, these genes only affected people using tirzepatide, not semaglutide.

Among all patients, weight loss on a GLP-1 drug varied between 6% and 20% of starting weight, and odds of nausea or vomiting varied between 5% and 78%, depending on their genetics.

“The study demonstrates the incredible power of our crowdsourced research community to advance scientific understanding of human genetic variation,” study co-author Adam Auton, vice president of human genetics at the 23andMe Research Institute, said in a news release.

More information

The Cleveland Clinic has more on GLP-1 drugs.

SOURCE: 23andMe Research Institute, news release, April 8, 2026