When to call a clinician: the symptoms the labels name

This page is the Medication Guide's warning list, sorted by urgency. Every item below is worded from the guides that come with Wegovy and Zepbound; the Ozempic and Mounjaro guides carry the same warnings. Ordinary nausea, softer stools, feeling full and a little tiredness are on the weeks pages, not here.

Call emergency services

• Serious allergic reaction. Swelling of your face, lips, tongue or throat; problems breathing or swallowing; severe rash or itching; fainting or feeling dizzy; very rapid heartbeat. The labels report anaphylaxis and angioedema (section 5, serious hypersensitivity reactions). Stop the drug and do not take it again until a clinician has seen you.
• Thoughts of suicide or self-harm, or a sudden change in mood or behaviour. Earlier Wegovy and Zepbound labels told prescribers to monitor for depression and suicidal thoughts; FDA removed that warning in February 2026 after reviewing the evidence. A sudden change in mood is still a reason to call. In the US, call or text 988 at any hour.

Call your prescriber the same day

• Severe pain in your stomach area that will not go away, with or without vomiting, possibly felt through to your back. This is the acute pancreatitis warning (section 5). Stop the drug until you have spoken to someone.
• Vomiting that does not stop, or diarrhea that prevents you keeping fluids down. This is the dehydration and acute kidney injury warning (section 5), covered in hydration.
• Pain in the upper stomach, fever, yellowing of the skin or eyes, or clay-coloured stools. This is the acute gallbladder disease warning (section 5). Gallstones become more likely with rapid weight loss.
• Severe constipation with stomach pain, bloating and vomiting. The labels list ileus among post-marketing reports (section 6.2).
• Signs of low blood sugar if you take insulin or a sulfonylurea: shakiness, sweating, confusion, fast heartbeat, blurred vision, feeling very hungry or irritable. Treat the low first, then call (section 5.4).
• A lump or swelling in your neck, hoarseness, trouble swallowing, or shortness of breath. These are the symptoms the Medication Guide asks you to report under the boxed warning about thyroid C-cell tumors. They are not common; they are on the list because the guide puts them there.

Call within a few days

• Vision changes, if you have type 2 diabetes. The semaglutide labels warn about complications of diabetic retinopathy (Ozempic and Wegovy section 5). Report any change in vision.
• A racing heart at rest that you notice repeatedly. The labels report a mean increase in resting heart rate; palpitations that persist are worth a call.
• Injection site reactions that spread, get hot, or do not fade. Redness and itch are common; spreading warmth is not.
• Dizziness on standing, dark urine, headaches that do not lift. Early dehydration; the fix is on the hydration page and the call is to confirm nothing else is going on.

Tell someone in advance

• Any planned surgery, endoscopy or sedation. The labels warn about pulmonary aspiration during general anesthesia or deep sedation and tell you to inform the team performing the procedure (section 5). Tell them, and ask the prescriber whether to pause before the date.
• Pregnancy, or a plan for one. The Wegovy label says to stop at least two months before a planned pregnancy (section 8.1). Tirzepatide has a separate note about oral contraceptive pills losing effect for four weeks after starting and after each step up (Zepbound section 7.1).

What to have ready when you call

Product and dose, date and time of the last injection, when the symptom started, what you have eaten and drunk in the last 24 hours, your temperature if you have one, and any other medicines you take. If you are on a compounded product, the pharmacy name and the concentration on the vial; compounded products are not FDA approved and are not interchangeable with brand products, and the clinician will want to know exactly what you have.

Reporting

Side effects from any prescription product, brand or compounded, can be reported to FDA's MedWatch program as well as to your prescriber and the manufacturer or pharmacy. Reports are how the post-marketing warnings on this page came to exist.