If you’re on GLP-1 drugs and plan to fast for Yom Kippur, here’s what you need to know
Fasting for Yom Kippur ends at nightfall with a family meal. halbergman/E+ via Getty Images Millions of people worldwide – as many as 1 in 8 adults in the U.S.
GLP-1 drugs, such as Ozempic, Mounjaro, Wegovy, and Zepbound, are medications used to treat diabetes or aid in weight loss. They work by mimicking a natural gut hormone called glucagon-like peptide 1 (GLP-1), which helps lower blood sugar by triggering insulin release when levels are high. These drugs also slow digestion, reducing appetite and aiding weight loss. As of 2026, up to 1 in 8 adults in the U.S. are taking GLP-1 medications, reflecting their widespread use. Common side effects include nausea, vomiting, dizziness, constipation, and dehydration, which may worsen during fasting periods like Yom Kippur.
Fasting during Yom Kippur involves abstaining from food and water for about 25 hours, which can significantly impact metabolism. For people on GLP-1 drugs, fasting may exacerbate side effects such as nausea, dizziness, or dehydration. The risk is higher when starting a new GLP-1 medication or increasing the dose within two weeks before the fast. GLP-1 drugs slow digestion, which can make fasting more difficult by prolonging feelings of fullness or discomfort. People with diabetes or those prone to gastrointestinal issues should be particularly cautious.
Most GLP-1 drugs are administered as weekly injections that should be taken as scheduled, even during fasting. These medications remain active in the body for the entire week, so skipping or moving the dose can interfere with their effectiveness in managing blood sugar or weight. If the injection falls on Yom Kippur, it is generally safe to take it as usual. However, some people may experience increased nausea on injection day, in which case delaying the dose until after the fast—with a doctor’s approval—may be preferable.
For those taking GLP-1 drugs daily, timing the dose around the fast is important. People using these medications for diabetes may take the injection right before the meal that breaks the fast or delay it until afterward to reduce stomach-related side effects, which are more likely when taken on an empty stomach. Oral GLP-1 medications, which must be taken on an empty stomach with a small amount of water, present a challenge during fasting since water is restricted. Skipping a dose is not harmful for weight loss but can be dangerous for diabetics due to the risk of high blood sugar.
The risks of fasting while on GLP-1 drugs differ depending on whether the medication is used for diabetes or weight loss. For weight management, fasting may cause stomach upset but is generally safe. However, in rare cases, it can stress the pancreas and lead to pancreatitis. For diabetics, the risk is higher, especially when GLP-1 drugs are combined with insulin or sulfonylureas, which lower blood sugar. This combination can cause blood sugar to drop too low during a fast. People with Type 1 diabetes, poorly controlled diabetes, frequent blood sugar drops, or severe gastrointestinal side effects should avoid fasting.
Before fasting, consult a doctor to assess whether it is safe, especially if you have diabetes or experience severe side effects from GLP-1 drugs. Eat a balanced meal with protein before the fast to avoid overeating or undereating, as both can worsen side effects. Stay hydrated beforehand, as GLP-1 drugs can suppress natural thirst signals. Diabetics should monitor blood sugar closely and be prepared to break the fast if symptoms like dizziness, confusion, or nausea occur. Keep rapid-acting carbohydrates, such as glucose tablets or hard candies, nearby. Break the fast with a gentle, balanced meal to avoid nausea or digestive issues.
