Ozempic side effects are the unwanted effects reported with Ozempic (semaglutide) injection, a once-weekly type 2 diabetes medicine, as listed in its FDA prescribing information.
- Most common
- Nausea, vomiting, diarrhea, stomach pain, constipation [1]
- Nausea rate
- 15.8% (0.5 mg) and 20.3% (1 mg) vs 6.1% placebo [1]
- Stopped for GI effects
- 3.1% (0.5 mg) and 3.8% (1 mg) vs 0.4% placebo [1]
- Boxed warning
- Thyroid C-cell tumors in rodents; human risk unknown [1]
- Approved for
- Type 2 diabetes, not weight loss [1]
What the Ozempic label lists as common
Ozempic is a type 2 diabetes medicine. Its label lists three uses: lowering blood sugar in adults with type 2 diabetes, lowering the risk of heart attack, stroke and cardiovascular death in adults with type 2 diabetes and heart disease, and lowering kidney and heart risks in adults with type 2 diabetes and chronic kidney disease [1]. It is not approved for weight loss. People who take it only to lose weight are using it off-label, and the semaglutide brand labeled for weight loss is Wegovy. Wegovy's side effect numbers come from different doses and people, so they are on the Wegovy side effects page.
| Reaction | Placebo | Ozempic 0.5 mg | Ozempic 1 mg |
|---|---|---|---|
| Nausea | 6.1% | 15.8% | 20.3% |
| Vomiting | 2.3% | 5.0% | 9.2% |
| Diarrhea | 1.9% | 8.5% | 8.8% |
| Abdominal pain | 4.6% | 7.3% | 5.7% |
| Constipation | 1.5% | 5.0% | 3.1% |
| Indigestion (dyspepsia) | 1.9% | 3.5% | 2.7% |
| Burping (eructation) | 0% | 2.7% | 1.1% |
| Reflux (GERD) | 0% | 1.9% | 1.5% |
Fatigue, a change in taste (dysgeusia) and dizziness were also reported more often than with placebo, at rates higher than 0.4% [1]. Average heart rate rose by 2 to 3 beats per minute, and the pancreatic enzymes lipase and amylase rose by an average of 22% and 13% [1].
Nausea, diarrhea, constipation and heartburn
Ozempic slows how fast the stomach empties [1]. That is one reason nausea, fullness, burping and reflux are the side effects people notice first. The label does not give a set number of days that nausea lasts. In the STEP 1 trial of semaglutide 2.4 mg (the Wegovy dose), nausea and diarrhea were the most common events and were typically transient and mild to moderate [2]. Doses are raised in steps of at least 4 weeks, which gives the body time to adjust [1].
Diarrhea affected 8.5% to 8.8% of people on Ozempic and constipation 3.1% to 5.0% [1]. After approval, reports came in of ileus, intestinal blockage and severe constipation, including fecal impaction [1]. Ozempic is not recommended for people with severe gastroparesis (very slow stomach emptying) [1]. Ask your prescriber before taking anti-diarrhea or laxative products, and call them if you cannot keep fluids down.
Tiredness, headaches, mood and sleep
Fatigue is listed as a reported reaction, at rates higher than 0.4%, but the label does not give a duration [1]. Headache appears in the list of reports received after approval, where the true rate cannot be measured [1]. Eating much less can also leave people tired, so tell your prescriber if fatigue does not ease.
The Ozempic label's warnings do not include a section on depression, anxiety or suicidal thoughts [1]. A related warning was removed from the Wegovy and Zepbound labels in February 2026 [3]. Mood changes still deserve a call to your clinician, and anyone with thoughts of self-harm should call 911.
Hair loss, Ozempic face and other nicknames
Hair loss (alopecia) is in the Ozempic label's list of reports received after approval, without a rate [1]. In Wegovy's weight trials, hair loss was reported in 3% on 2.4 mg and 6% on 7.2 mg, compared with 1% on placebo [4].
"Ozempic face," "Ozempic butt," "Ozempic feet" and "Ozempic teeth" are media and social media nicknames, not medical terms. They usually describe a thinner, looser look after fast weight loss. The adverse reaction sections of the Ozempic label do not use these terms or list facial changes [1]. No label instruction exists for preventing or reversing them. If a change in your face, skin or teeth worries you, ask your prescriber or dentist; we did not find label-based data on whether these changes reverse.
Serious warnings: pancreas, gallbladder, kidneys and eyes
- Pancreatitis. Acute pancreatitis, including fatal and non-fatal hemorrhagic or necrotizing forms, has been reported. Stop Ozempic if it is suspected [1].
- Gallbladder. Gallstones occurred in 1.5% on 0.5 mg and 0.4% on 1 mg, vs 0% on placebo [1].
- Kidneys. Acute kidney injury, sometimes needing dialysis, has been reported, mostly after vomiting or diarrhea caused dehydration [1].
- Eyes. In the 2-year SUSTAIN 6 heart outcomes trial, diabetic retinopathy complications occurred in 3.0% on Ozempic vs 1.8% on placebo, and in 8.2% vs 5.2% among people who already had retinopathy [1].
- Low blood sugar. Risk rises when Ozempic is used with insulin or a sulfonylurea [1].
- Anesthesia. Food or liquid entering the lungs (pulmonary aspiration) has been reported during general anesthesia or deep sedation. Tell your care team before any procedure [1].
- Allergy. Anaphylaxis and angioedema have been reported [1].
Questions about blurred vision usually trace back to the eye warning. The label ties worsening diabetic retinopathy to people with diabetes, especially those with existing eye disease [1]. Any sudden change in vision needs prompt medical attention. Tell your eye doctor you take Ozempic.
When to get help fast
Stop Ozempic and call your prescriber right away for severe stomach pain that will not go away, with or without vomiting, which can be a sign of pancreatitis [1]. Get emergency care for swelling of the face, lips, tongue or throat, trouble breathing or a fast heartbeat, which can signal a serious allergic reaction [1]. If you also use insulin or a sulfonylurea, watch for shakiness, sweating, confusion or a racing heart, which can mean low blood sugar [1]. Tell your prescriber about a lump or swelling in the neck, trouble swallowing or a hoarse voice that lasts, because of the thyroid tumor boxed warning [1]. In an emergency, call 911.
Does Ozempic cause cancer?
The boxed warning on Ozempic says semaglutide caused thyroid C-cell tumors in rodents; whether it causes them in people, including medullary thyroid carcinoma (MTC), is unknown [1]. Ozempic is not for anyone with a personal or family history of MTC or Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) [1]. Other cancers are not listed as known risks. A question like "has anyone got thyroid cancer from Ozempic" has no answer in the label beyond that statement that human risk is unknown.
Muscle, energy and other common questions
Body composition is not reported in the Ozempic label. For tirzepatide, a different medicine, a trial substudy found about 25% of weight lost was lean mass [5]; see our guide to keeping muscle on a GLP-1 and what to eat on Ozempic. Ozempic is not a stimulant, and the label does not say it raises energy. Injection areas are the abdomen, thigh or upper arm, and the label does not link any one area to fewer side effects [1]; see how to use Ozempic.
Counterfeit Ozempic has been found in the US and may contain wrong or harmful ingredients [6]. Buy from a state-licensed pharmacy. Compounded semaglutide is not FDA-approved, and FDA does not review it for safety, effectiveness or quality [7]. FDA has received reports of dosing errors with compounded semaglutide, some needing hospital care [6]. See compounded semaglutide for details.
Related pages
Compare side effects across the class on our GLP-1 side effects page, see how Ozempic compares with Mounjaro, check trial averages on Ozempic results, read what affects your bill on Ozempic cost, and see Ozempic dosage for the dose schedule.
Questions people ask
What are the most common side effects of Ozempic?
Nausea, vomiting, diarrhea, stomach pain and constipation. In Ozempic's diabetes trials, nausea affected 15.8% of people on 0.5 mg and 20.3% on 1 mg vs 6.1% on placebo [1].
Does Ozempic cause hair loss?
What is Ozempic face?
It is a media nickname for a thinner or looser-looking face after fast weight loss, not a medical diagnosis. The Ozempic label's adverse reaction sections do not use the term or list facial changes [1].
Does Ozempic cause cancer?
Ozempic has a boxed warning because semaglutide caused thyroid C-cell tumors in rodents. Whether it causes these tumors in humans is unknown, and people with a personal or family history of medullary thyroid carcinoma or MEN 2 should not use it [1].
Does Ozempic make you tired?
Fatigue is a reported reaction in the Ozempic label, at rates higher than 0.4% [1]. The label gives no duration. Tell your prescriber if tiredness does not improve.
Can Ozempic cause blindness or blurred vision?
The label warns about diabetic retinopathy complications. In SUSTAIN 6 they occurred in 3.0% on Ozempic vs 1.8% on placebo, and 8.2% vs 5.2% in people with existing retinopathy [1]. Report any sudden vision change promptly.
Can Ozempic cause pancreatitis?
Yes. The label warns that acute pancreatitis, including fatal forms, has been reported. Stop Ozempic and call your prescriber for severe stomach pain that will not go away [1].
Does Ozempic cause depression or anxiety?
The Ozempic label's warnings do not include a mood or suicidal-thoughts section [1]. Talk with your clinician about any mood change, and call 911 for thoughts of self-harm.
Sources
7 cited
- Ozempic (semaglutide) injection prescribing information. DailyMed, U.S. National Library of Medicine, May 2026.
- STEP 1 trial of semaglutide 2.4 mg in adults with overweight or obesity (Wilding et al., NEJM 2021), PubMed record. PubMed, National Library of Medicine, Feb 10, 2021.
- Zepbound (tirzepatide) injection prescribing information. DailyMed, U.S. National Library of Medicine, Aug 2026.
- Wegovy (semaglutide) injection and tablets prescribing information. DailyMed, U.S. National Library of Medicine, Jun 2026.
- SURMOUNT-1 body composition substudy (Look et al., Diabetes Obes Metab 2025), PubMed record. PubMed, National Library of Medicine, Feb 25, 2025.
- FDA's concerns with unapproved GLP-1 drugs used for weight loss. U.S. Food and Drug Administration, Oct 1, 2026.
- Compounding and the FDA: questions and answers. U.S. Food and Drug Administration, 2025-09-16 (accessed 2026-10-17).
This page is general information, not medical advice. Talk with a licensed clinician about your own care.