This page summarizes what the current FDA labels for semaglutide (Ozempic, Wegovy), tirzepatide (Mounjaro, Zepbound) and liraglutide (Saxenda, Victoza) say about side effects, and how to record them in STACK so your prescriber gets a clear picture. It is not a guide to managing side effects. The label wording on when to call your prescriber or get emergency help is quoted directly. Nothing here changes what your prescriber told you.

The common ones: stomach and gut

Gastrointestinal effects lead every label. For Wegovy injection in adults, nausea was reported by 44% of treated patients versus 16% on placebo; diarrhea 30% vs 16%; vomiting 24% vs 6%; constipation 24% vs 11%; abdominal pain 20% vs 10% [1]. For Zepbound, nausea ranged from 25% to 29% across the studied strengths versus 8% on placebo, with diarrhea 19–23%, vomiting 8–13% and constipation 11–17% [3]. The Ozempic label lists nausea, vomiting, diarrhea, abdominal pain and constipation as the reactions reported in 5% or more of patients [2]. Mounjaro adds decreased appetite and dyspepsia to that list [4]. Saxenda’s most common reactions also include injection site reactions, headache, hypoglycemia, fatigue and dizziness [5], and Victoza’s include decreased appetite and dyspepsia [6]. All six labels carry a “Severe Gastrointestinal Adverse Reactions” warning section [1][2][3][4][5][6].

The warnings on every label

Each of the six labels opens with the same boxed warning: risk of thyroid C-cell tumors. In rodents, these drugs cause thyroid C-cell tumors; it is unknown whether they do so in humans, and they are contraindicated in people with a personal or family history of medullary thyroid carcinoma or with MEN 2 [1][2][3][4][5][6].

The Warnings and Precautions sections then list, with small differences in order: acute pancreatitis; acute gallbladder disease; hypoglycemia, especially with insulin or an insulin secretagogue such as a sulfonylurea; acute kidney injury due to volume depletion; hypersensitivity reactions including anaphylaxis and angioedema; and pulmonary aspiration during general anesthesia or deep sedation [1][2][3][4][5][6]. The semaglutide and tirzepatide labels add diabetic retinopathy complications in patients with type 2 diabetes [1][2][3][4]. Saxenda and Wegovy add a heart rate increase warning [1][5].

On suicidal thoughts: the Wegovy, Zepbound and Saxenda labels’ “Recent Major Changes” tables record that the “Suicidal Behavior and Ideation” warning subsection was removed in February 2026 [1][3][5]. That is a change in the label text, not a reason to ignore mood changes; report them to your prescriber like any other symptom.

What the labels say about calling for help

The Medication Guide language is specific, and it is the language STACK echoes. For pancreatitis: “Stop using WEGOVY and call your healthcare provider right away if you have severe pain in your stomach area (abdomen) that will not go away, with or without nausea or vomiting. Sometimes you may feel the pain from your abdomen to your back” [1]. Zepbound uses the same wording [3].

For serious allergic reactions, both say to stop the drug and “get medical help right away” for swelling of the face, lips, tongue or throat, problems breathing or swallowing, severe rash or itching, fainting or a very rapid heartbeat [1][3].

For dehydration: “Tell your healthcare provider right away if you have nausea, vomiting, or diarrhea that does not go away” [1][3]. For gallbladder symptoms (upper abdominal pain, fever, jaundice, clay-colored stools), call your healthcare provider [1][3]. For thyroid symptoms: “Tell your healthcare provider if you get a lump or swelling in your neck, hoarseness, trouble swallowing, or shortness of breath” [1]. For a suspected overdose: “call your healthcare provider or Poison Help line at 1-800-222-1222 or go to the nearest hospital emergency room right away” [1][3]. Before any surgery or procedure with anesthesia or deep sedation, the labels say to tell all your healthcare providers you are taking the drug [1][3].

What to log in STACK

STACK’s side-effect log is built so the entry is useful to a prescriber later. For each event, record:

Symptom, chosen from the label’s list (nausea, vomiting, diarrhea, constipation, abdominal pain, dyspepsia, headache, fatigue, dizziness, injection site reaction) or free text.
Severity on a simple 0–3 scale, and whether it stopped you eating, drinking or working.
Timing relative to your last dose: STACK stamps the hours since the dose you logged, so patterns near the peak show up.
Food: what and when you last ate, since the labels note these drugs delay gastric emptying [1][3].
Hydration: fluids kept down that day. The labels single out fluid loss as the route to kidney problems [1][3].
Blood glucose, if your prescriber asked you to check it and you take insulin or a sulfonylurea [1][3].
Injection site and any local reaction.

STACK never grades a symptom for you or suggests changing a dose. What it does is put the entry on the same timeline as your logged doses and estimated level, so you and your prescriber can see whether a symptom clusters after injections or after a step-up your prescriber scheduled.

Reporting

The FDA accepts side-effect reports directly from patients and consumers through MedWatch, using the online form or the consumer version of Form FDA 3500 [7]. Your prescriber is not required to file a report for you [7]. STACK’s log export gives you the dates and details a report asks for.

Free tools

Sources

Every URL below was fetched and checked on 2026-09-24. Bracketed numbers in the text link here.

GLP-1 side effects: what the labels list and what to track