GLP-1s have been lauded as a life-changing treatment for those trying to shed weight and adjust their relationship with food, but as with any medication, they’re not without side effects. “As a family physician, I often see patients experience a few predictable side effects when starting GLP-1 medications like semaglutide or liraglutide,” says Arlington, VA family physician Elizabeth Kazarian, MD. “While these side effects can be uncomfortable, they’re usually manageable with the right guidance and adjustments.”
Unsurprisingly, digestive issues tend to be the most common, especially in the first few weeks as your body adjusts, says New York endocrinologist at Found Rekha Kumar, MD. “For most people, these are temporary, and with the right clinical support and a gradual approach to dosing, most people find they fade quickly and can stay on track with their health goals.” Additionally, “With lower-dose approaches like microdosing, which many of our prevention-minded patients choose, these effects tend to be even milder,” she notes.
Below, we’ve listed some of the most common side effects, along with expert-recommended solutions. However, it’s important to note that everyone responds differently to these medications and you should always check with your doctor before starting or adjusting a GLP-1, says Dr. Kazarian. “Your care should be as individual as your health goals.” Dr. Kumar agrees, noting that at Found, where she is a medical advisor, each patient gets personalized guidance. “You’re never managing this alone.”
Featured Experts
- Elizabeth Kazarian, MD is a board-certified family physician in Arlington, VA
- Rekha Kumar, MD is a board-certified endocrinologist at Found in New York
Pro Tip: What and How You Eat Can Affect Your GLP-1 Side Effects
“How you eat is just as important as what you eat when it comes to GLP-1s,” says Dr. Kumar. She says focusing on whole, unprocessed foods is key. “Smaller portions, eating slowly and avoiding heavy or fried foods can make a huge difference in how you feel, especially early on or on the days you dose.”
“Protein also deserves a bit more attention when you’re using GLP-1s—it keeps your energy stable, protects your muscle tone and helps you feel satisfied without discomfort,” says Dr. Kumar. However, she notes that the protein craze can go too far. “Most women don’t need to hit the grams being glorified by many wellness influencers. Potentially as important as protein, for example, is to add in plenty of fiber from vegetables and fruits and to stay well-hydrated,” says Dr. Kumar. “These are foundational for metabolic health, whether or not you’re using GLP-1s.”
The Most Common GLP-1 Side Effects
Nausea
Dr. Kazarian says nausea tends to be the most common side effect, especially during the initial weeks or dose increases. “To ease nausea, I advise patients to eat smaller meals, avoid greasy or rich foods and increase the dose slowly,” says Dr. Kazarian. Dr. Kumar has similar advice, noting that if nausea pops up, it’s best to “stick with simple, nutritious foods and spread your meals evenly throughout the day.”
Digestive issues
Constipation is frequently reported, says Dr. Kazarian, though some experience diarrhea instead. “For constipation, hydration and fiber are key—I recommend aiming for 25 to 30 grams of fiber per day through fruits, vegetables, whole grains, legumes or a fiber supplement if needed,” says Dr. Kazarian. “Light exercise, like walking, can also help digestion.” If necessary, Dr. Kumar says you can consider a gentle over-the-counter solution as well. On the other hand, if diarrhea occurs, Dr. Kazarian says “sticking to a bland diet and avoiding caffeine or spicy foods can provide relief.”
Appetite loss
“Feeling full earlier or having less appetite isn’t really a side effect—it’s how the medication works to support your metabolism,” says Dr. Kumar. However, Dr. Kazarian explains that “Decreased appetite is expected and often desired, but in some cases, it can become too pronounced.” If you’re experiencing a total loss of appetite, she recommends focusing on small but nutrient-dense meals like smoothies, soups and high-protein snacks.
Fatigue
Fatigue or low energy levels may occur, particularly if a patient isn’t eating enough or staying hydrated, says Dr, Kazarian. It may sound simple, but she says fatigue often improves once hydration and calorie intake are addressed. “Some patients notice mild fatigue or heartburn, particularly after richer meals, which is why nutrition matters so much,” says Dr. Kumar. “Staying hydrated and keeping a consistent eating schedule is key—it helps prevent fatigue and keeps energy steady.”
