Weight-loss drugs such as Ozempic and Wegovy could make fasting feel easier for some people by reducing hunger and food cravings, research suggested, although evidence that they help people comfortably complete a prolonged fast remained limited.
The question is especially relevant ahead of Yom Kippur, when observant Jews abstain from food and drink for about 25 hours. It also extends to Muslims fasting during Ramadan and people following intermittent-fasting diets.
Semaglutide, the active ingredient in Ozempic and Wegovy, acts on pathways involved in appetite regulation. For someone already taking the medication, feeling less hungry could make the hours without food more manageable. How that translates into the experience of a full day of fasting requires closer examination.
A 2017 randomized trial involving 30 adults with obesity offered evidence relevant to that question. After 12 weeks of treatment, participants taking semaglutide had greater appetite suppression in the fasting state before a standardized breakfast than when they received a placebo.
They also reported fewer food cravings and better control over eating. During meals at which they could eat freely on the assessment day, their combined calorie intake was about 24% lower with semaglutide.
Similarity of nausea ratings supports lower food intake interpretation
Nausea ratings at the assessment were similar between treatments, supporting the researchers’ interpretation that reduced appetite helped explain the lower food intake. Gastrointestinal side effects did occur during the trial, and two participants withdrew while receiving semaglutide.
The trial investigated appetite and eating behavior. It did not test whether participants could complete a 25-hour fast without food or water more easily.
Research during Ramadan addressed a different part of the question: how diabetes medication performed while patients fasted.
The LIRA-Ramadan trial, published in 2016, compared liraglutide, another GLP-1 drug, with sulfonylureas in people with type 2 diabetes. Researchers reported fewer episodes of low blood sugar with liraglutide during Ramadan, alongside similar improvements in blood-sugar control.
Those findings concerned a specific patient group and a comparison between treatments. They did not establish that semaglutide made fasting less uncomfortable. Ramadan also allows eating and drinking each night, while the Yom Kippur fast continues through the night and following day.
Researchers have considered whether appetite suppression could help people follow intermittent-fasting schedules. A December 2025 review in Biomedicines proposed combining GLP-1 treatment with structured fasting and dietary changes. Its authors described a possible treatment framework and called for randomized trials to validate the approach.
Personal accounts have already brought the issue into Jewish life. In an August 28 Hadassah Magazine article, a 46-year-old New York mother identified as Beth described getting through Yom Kippur services without thinking about food after starting a GLP-1 medication.
Her experience illustrated what appetite suppression could mean during a religious fast. Establishing how common that experience is would require broader research.
Medical safety an individual question
Medical safety remains an individual question. Wegovy’s prescribing information and patient guidance warn that nausea, vomiting, and diarrhea can cause dehydration. Low-blood-sugar risks also increase when the medication is used with insulin or certain other diabetes treatments.
People planning to fast should discuss their health conditions and medication regimen with their treating clinician. The appetite findings provide no basis for starting the drugs or changing a dose solely to get through a fast.
For existing users, reduced hunger may change how fasting feels. The research supports that possibility; how reliably it improves the experience of a prolonged religious fast remains an open question.