Common side effects
GLP-1 medications such as semaglutide and tirzepatide slow digestion and reduce appetite, so most side effects involve the digestive system:
- Nausea — the most common, especially early on
- Diarrhea or constipation
- Vomiting
- Stomach pain, bloating, burping or heartburn
- Fatigue or headache in some people
These are usually strongest in the days after starting or increasing a dose and often ease over a few weeks. This is why doses are increased gradually.
Practical tips that help
For nausea
- Eat smaller meals and stop as soon as you feel full.
- Eat slowly; avoid lying down right after eating.
- Limit greasy, fried and very sweet foods.
- Bland foods such as crackers, rice and toast can help on rough days.
For constipation
- Drink plenty of water throughout the day.
- Add fiber gradually (vegetables, fruit, whole grains).
- Stay active — even short walks help.
For diarrhea
- Hydrate and replace electrolytes.
- Avoid high-fat meals and sugar alcohols.
Protect your muscle and energy
- Prioritize protein at every meal.
- Add strength training two to three times a week if you can.
If side effects make it hard to eat or drink, your provider may slow your dose increases or keep you at a lower dose longer. Don't adjust your dose on your own.
Serious but less common risks
GLP-1 medications have important warnings your provider will review with you, including:
- Pancreatitis — severe, persistent abdominal pain that may spread to the back, with or without vomiting
- Gallbladder problems — pain in the upper right abdomen, fever, yellowing of skin or eyes
- Dehydration and kidney problems, often from vomiting or diarrhea
- Low blood sugar when combined with insulin or sulfonylureas
- Thyroid C-cell tumors seen in animal studies — GLP-1s are not used in people with a personal or family history of medullary thyroid cancer or MEN 2
When to get help
Seek medical care promptly for severe or persistent abdominal pain, vomiting that prevents you from keeping fluids down, signs of dehydration (dizziness, very little urine), yellowing of the skin or eyes, or an allergic reaction (swelling of the face or throat, trouble breathing). Call 911 for emergencies.
Support at EdenRx
EdenRx patients can reach their care team between refills, and our medical team under Dr. Jean-Yves Dastain, MD adjusts dosing based on how you feel. Read more: Is semaglutide safe? · Is tirzepatide safe?
This article is for education only and is not medical advice. Contact your provider about any symptoms.
