If you’re on GLP-1 drugs and plan to fast for Yom Kippur, here’s what you need to know

(The Conversation) — Millions of people worldwide – as many as 1 in 8 adults in the U.S. – are on GLP-1 medication, such as Ozempic, Mounjaro, Wegovy and Zepbound, for treating diabetes or for weight loss.

These drugs are adding a medical twist to religious observances that involve fasting, such as the Jewish holiday of Yom Kippur, which will be observed from sundown on Sept. 20 until nightfall on Sept. 21, 2026. Traditionally, fasting on Yom Kippur means forgoing food and water for about 25 hours, which can strongly affect a person’s metabolism.

Other religious traditions include different types of fasts. For example, Muslims who fast during Ramadan neither eat nor drink from dawn to sunset, but they break their fast each night. Christian and Hindu traditions also include dry fasts as well as partial fasts, such as Lent and Navratri , in which people avoid certain foods.

As a specialist in obesity medicine , I work with many patients who take GLP-1 drugs. Most people can safely fast for Yom Kippur or other religious or cultural observances. But depending on their circumstances, they may need to plan ahead, take certain precautions and be clear on when it’s medically advised…