Short answer: In the label's placebo-controlled trials, the most common side effect of Ozempic was nausea: 15.8% on 0.5 mg and 20.3% on 1 mg, against 6.1% on placebo. Vomiting, diarrhea, stomach pain and constipation followed. Most nausea, vomiting and diarrhea happened while the dose was being raised. The label carries a boxed warning about thyroid C-cell tumors seen in rodents.
What Ozempic is approved for: The label says Ozempic is approved, along with diet and exercise, to improve blood sugar control in adults with type 2 diabetes. It is also approved to lower the risk of major heart events in adults with type 2 diabetes and known heart disease, and to lower the risk of kidney decline, kidney failure and death from heart causes in adults with type 2 diabetes and chronic kidney disease.
Source
OZEMPIC (semaglutide) injection, for subcutaneous use, prescribing information and Medication Guide. Novo Nordisk. DailyMed, version published June 10, 2026. DailyMed setid adec4fd2-6858-4c99-91d4-531f5f2a2d79
WARNING: RISK OF THYROID C-CELL TUMORS
In rodents, semaglutide caused thyroid C-cell tumors, and it is not known whether Ozempic causes these tumors, including medullary thyroid carcinoma (MTC), in people. Ozempic must not be used by people with a personal or family history of MTC or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2). The label lists a lump in the neck, trouble swallowing, shortness of breath and lasting hoarseness as possible thyroid tumor symptoms.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Ozempic.
| Adverse reaction | Placebo (N=262) % | Ozempic 0.5 mg (N=260) % | Ozempic 1 mg (N=261) % |
|---|---|---|---|
| Nausea | 6.1 | 15.8 | 20.3 |
| Vomiting | 2.3 | 5 | 9.2 |
| Diarrhea | 1.9 | 8.5 | 8.8 |
| Abdominal pain | 4.6 | 7.3 | 5.7 |
| Constipation | 1.5 | 5 | 3.1 |
Pooled from 2 placebo-controlled trials in adults with type 2 diabetes (one with Ozempic alone, one added to basal insulin): 521 patients took Ozempic for a mean of 32.9 weeks. Low blood sugar is not included in this table.
| Trial and definition | Placebo | Ozempic 0.5 mg | Ozempic 1 mg |
|---|---|---|---|
| Monotherapy: Severe† | 0% | 0% | 0% |
| Monotherapy: Documented symptomatic (≤70 mg/dL glucose threshold) | 0% | 1.6% | 3.8% |
| Monotherapy: Severe† or Blood Glucose Confirmed Symptomatic (≤56 mg/dL glucose threshold) | 1.6% | 0% | 0% |
| Add-on to Basal Insulin: Severe† | 0% | 0% | 1.5% |
| Add-on to Basal Insulin: Documented symptomatic (≤70 mg/dL glucose threshold) | 15.2% | 16.7% | 29.8% |
| Add-on to Basal Insulin: Severe† or Blood Glucose Confirmed Symptomatic (≤56 mg/dL glucose threshold) | 5.3% | 8.3% | 10.7% |
Two 30-week trials: Ozempic used alone (N=129 placebo, 127 on 0.5 mg, 130 on 1 mg) and Ozempic added to basal insulin with or without metformin (N=132, 132, 131). "Severe" means an episode that needed another person's help.
Stomach and gut side effects overall: 15.3% on placebo, 32.7% on 0.5 mg and 36.4% on 1 mg. In a separate trial, they were reported in 34% on 2 mg and 30.8% on 1 mg.
Stopping treatment because of stomach and gut side effects: 3.1% on 0.5 mg and 3.8% on 1 mg, against 0.4% on placebo.
Injection site reactions (such as discomfort or redness) were reported in 0.2% of people on Ozempic in placebo-controlled trials.
With a sulfonylurea, severe low blood sugar occurred in 0.8% on 0.5 mg and 1.2% on 1 mg, and documented symptomatic low blood sugar in 17.3% and 24.4%.
Heart rate rose by a mean of 2 to 3 beats per minute on 0.5 mg and 1 mg. Amylase rose by a mean of 13% and lipase by 22% from baseline.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Risk of thyroid C-cell tumors. Semaglutide caused thyroid C-cell tumors in mice and rats; whether this happens in people is unknown. People with a personal or family history of MTC or with MEN 2 must not use Ozempic.
Acute pancreatitis. Inflammation of the pancreas, including fatal cases, has been seen with GLP-1 drugs including Ozempic. The label says to stop Ozempic if pancreatitis is suspected.
Diabetic retinopathy complications. In a 2-year trial, eye complications from diabetes occurred in 3.0% on Ozempic and 1.8% on placebo. The rise was larger in people who already had diabetic retinopathy (8.2% vs 5.2%).
Never share a pen. Ozempic pens must never be shared between people, even if the needle is changed, because of the risk of passing on blood-borne infections.
Low blood sugar with insulin or sulfonylureas. Using Ozempic with insulin or a sulfonylurea may raise the risk of low blood sugar, including severe episodes. The label says a lower dose of those medicines may reduce this risk.
Kidney injury from fluid loss. Acute kidney injury, sometimes needing dialysis, has been reported, mostly in people who became dehydrated from nausea, vomiting or diarrhea. The label says to monitor kidney function in these people, especially when starting or raising the dose.
Severe stomach and gut side effects. Severe stomach and gut side effects were reported in 0.4% on 0.5 mg and 0.8% on 1 mg, against 0% on placebo. Ozempic is not recommended in people with severe gastroparesis.
Allergic reactions. Serious allergic reactions such as anaphylaxis and angioedema have been reported. The label says to stop Ozempic if they occur.
Gallbladder disease. Gallstones were reported in 1.5% on 0.5 mg and 0.4% on 1 mg in placebo-controlled trials, and in no one on placebo.
Food or liquid in the lungs during anesthesia. Ozempic slows stomach emptying. Rare reports describe food entering the lungs during procedures with general anesthesia or deep sedation. The label says to tell your providers you take Ozempic before any planned procedure.
From the Medication Guide that comes with Ozempic:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.