Mostly digestive, and mostly temporary: nausea, vomiting, diarrhea, abdominal pain, constipation, appetite loss, headache, and injection-site reactions.
They peak when starting or after a dose increase and ease as your body adjusts - which is why prescribers start low and titrate slowly. The exceptions to respect: low blood sugar risk when combined with insulin or sulfonylureas, muscle loss during rapid weight loss, and any severe persistent symptoms, which warrant a call.
What to do
Common questions
What are the side effects of GLP-1 drugs?
Mostly digestive, and mostly temporary. The common list from MedlinePlus: nausea, vomiting, diarrhea, abdominal pain, constipation, loss of appetite, headache, and injection-site reactions like rash or itching. These tend to hit hardest when starting or after a dose increase, then ease as the body adjusts - which is exactly why prescribers start low and step the dose up slowly. A few deserve extra respect: low blood sugar becomes a real risk when a GLP-1 drug is combined with insulin or sulfonylureas, so doses of those may need adjusting; reduced muscle mass is a recognized effect of rapid weight loss on these drugs, which makes protein intake and resistance exercise worth discussing with your prescriber; and any severe, persistent abdominal pain, vomiting that will not stop, or signs of dehydration warrant a prompt call. Never ignore symptoms hoping they pass. Pymander, a free AI doctor available 24/7 by text, can help you sort a new symptom into routine versus call-the-doctor.