Fasting on GLP-1s? Expert Advice for Yom Kippur

Millions worldwide, including up to 1 in 8 U.S. adults, are now using GLP-1 medications such as Ozempic and Wegovy for diabetes treatment or weight loss. These drugs mimic a natural gut hormone that regulates blood sugar and slows digestion, reducing appetite.

The upcoming Jewish holiday of Yom Kippur, observed from sundown September 20 to nightfall September 21, 2026, involves a nearly 25-hour fast, presenting new considerations for GLP-1 users. While most people can fast safely, potential exacerbation of common side effects like nausea, vomiting, and dehydration requires attention.

Individuals taking GLP-1s for weight management may experience stomach upset during a fast, but diabetic patients face greater risks. Combining GLP-1s with other blood-sugar-lowering medications, especially insulin or sulfonylureas, can significantly increase the danger of hypoglycemia (low blood sugar).

Experts recommend avoiding dose increases or starting new GLP-1 medications within two weeks of fasting. For weekly injections, maintaining the regular schedule is generally advised. Daily oral medications may require adjusting timing to avoid taking them on an empty stomach during the fast.

Patients with Type 1 diabetes, poorly controlled diabetes, a history of severe blood sugar drops, or severe kidney disease are strongly advised against fasting. Consulting a clinician before any religious observance is crucial for personalized guidance on medication timing, dosage adjustments, and determining fasting safety.