Common side effects
Most side effects of GLP-1 medicines involve the digestive system, because the drugs slow how quickly your stomach empties. They're most likely in the first weeks and after each dose increase, and usually fade.
- Nausea
- Diarrhea or constipation
- Vomiting
- Stomach pain, bloating, burping or indigestion
- Headache, tiredness and dizziness
Ways people manage them
- Eat smaller meals and stop when you first feel full.
- Go easy on greasy, fried and very sweet foods, especially around dose increases.
- Drink water through the day; dehydration makes nausea and kidney strain worse.
- Prioritize protein and keep up strength training to help protect muscle while you lose weight.
- Ask your clinician about staying on a dose longer before increasing if side effects are hard to tolerate.
Serious risks
Call your clinician promptly, or seek emergency care, if you have:
- Severe stomach pain that won't go away, with or without vomiting (possible pancreatitis)
- Pain in the upper right abdomen, fever or yellowing skin or eyes (possible gallbladder problems)
- Signs of dehydration or reduced urination
- Swelling of the face, lips or throat, or trouble breathing
- A lump or swelling in the neck, trouble swallowing or persistent hoarseness
- New or worsening depression or thoughts of self-harm
Semaglutide and tirzepatide carry a boxed warning about thyroid C-cell tumors seen in rodents. People with a personal or family history of medullary thyroid carcinoma or MEN 2 should not use them.
Before surgery or sedation
GLP-1 medicines slow stomach emptying, which can raise the risk of inhaling stomach contents under anesthesia. Tell your surgeon and anesthesiologist that you take one.
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