Ozempic side effects: which are common and which are serious?

Which Ozempic side effects are common?

The common ones are stomach and gut effects, such as feeling sick, vomiting, diarrhoea, stomach pain and constipation. Nausea and vomiting rise at 1 mg.

Ozempic is semaglutide, sold in India for type 2 diabetes in 0.25, 0.5 and 1 mg strengths.⁶ If the names confuse you, see Is semaglutide the same as Ozempic?

The US label pools 2 trials that compared Ozempic with a dummy injection (placebo). They included 521 people on Ozempic for about 33 weeks on average, and 19% were Asian.¹

Ozempic US label (revised May 2026), Table 1 and section 6.1: 2 placebo-controlled trials in adults with type 2 diabetes. Rounded to whole numbers.¹

A worked example. Picture 100 people on Ozempic 1 mg. About 20 will feel sick at some point, but about 6 would have felt sick on a dummy injection. So about 14 feel sick because of the medicine (our arithmetic).¹

On 0.5 mg, the label also lists indigestion (4%, against 2% on placebo). Burping (3%) and reflux or heartburn (2%) did not occur on placebo.¹ Resting heart rate rose by 2 to 3 beats a minute on average.¹

The EU label puts it in frequency bands, and we use its words on this page. "Very common" means more than 1 in 10 people, "common" 1 to 10 in 100, "uncommon" up to 1 in 100, "rare" up to 1 in 1,000 and "very rare" up to 1 in 10,000.² Across 8 trials with 4,792 people, nausea and diarrhoea were very common and vomiting common.²

The EU label also lists headache, tiredness and dizziness as common, and a changed sense of taste as uncommon.² Redness or discomfort where you inject is uncommon: 0.2% on the US label.^1,2

Stopping because of side effects. On the US label, 3% (0.5 mg) and 4% (1 mg) stopped because of stomach effects, against 0.4% on placebo.¹

At 2 mg, stomach effects hit 34%, against 31% on 1 mg, in a 40-week trial. Ozempic 2 mg is sold in the US and EU, not in India.^1,2,6

Why do Ozempic's numbers look lower than Wegovy's?

Wegovy is the same medicine at a higher weekly dose, 2.4 mg, tested in people without diabetes. Its trials found more stomach side effects.

In STEP 1, the main Wegovy trial, 44% felt sick on 2.4 mg over 68 weeks, against 17% on placebo.³ On Ozempic 1 mg in diabetes trials, it was 20% against 6%.¹ These are separate trials with different people, doses and lengths, so they can't show how much of the gap is the dose.

Guide 5: Side effects and risks covers Wegovy and Mounjaro. The two brands are compared in Wegovy vs Ozempic: same medicine, different brand?

What did Indian trials of Ozempic find?

Two 2026 trials in India gave some people Ozempic as the comparison for a local copy. Stomach effects were common, and mostly mild or moderate.

Both were paid for by Indian makers of generic semaglutide, and neither had a dummy-injection group.^4,5 So they show how often Indians on Ozempic reported side effects, not how many the medicine caused.

Sun Pharma's trial ran at 35 centres in India with 314 adults with type 2 diabetes, for 24 weeks, with doses rising from 0.25 mg to 2 mg.⁴ Stomach effects hit 47% on Ozempic and 43% on the copy, mostly mild to moderate.⁴ One person on Ozempic had low blood sugar that needed glucose through a drip.⁴

Alkem's SIZE-DM trial ran at 23 centres with 320 adults already on metformin, also for 24 weeks.⁵ In its Ozempic group of 160 people, 7% felt sick, 11% vomited, 9% had diarrhoea and 12% had gastritis (an inflamed stomach lining).⁵

The trial reported no serious side effects caused by either medicine.⁵ Both trials found the copies comparable to Ozempic on safety.^4,5 More on the copies: What changed for Ozempic when semaglutide's patent expired?

When do Ozempic side effects start, and when do they fade?

Mostly in the first months, while the dose is stepped up. For most people they ease with time, but constipation and reflux can linger.

The EU label says they were most often reported in the first months, and were mostly mild and short.²

These dose steps are from the US label; your doctor sets yours.¹

1. Weeks 1–40.25 mg once a week. This is a starting dose, and stomach effects can begin.¹
2. Week 5 on0.5 mg once a week. Nausea, vomiting and diarrhoea are most likely around dose steps.¹
3. 4+ weeks later1 mg, only if more sugar control is needed.¹
4. Months laterMost stomach effects settle.²

Some effects don't fade. In one trial where Ozempic was added to an SGLT2 inhibitor (another diabetes pill), constipation hit 7% and reflux 4%. They did not become less common over time.²

In the Wegovy trials, a bout of nausea lasted 8 days at the median, and constipation 47 days, against 35 days on placebo.⁷ Food tips that help are in Guide 5 and Guide 8: Life on a GLP-1.

Which Ozempic side effects are serious?

Pancreatitis, gallbladder disease, kidney injury from dehydration, and low blood sugar with insulin or sulfonylureas. On the EU label, pancreatitis is uncommon and gallstones common; its warnings say kidney harm happens in rare cases. Low sugar is very common with insulin or a sulfonylurea, but severe lows hit about 1% to 1.5%.

India's government lists the same range, from nausea and vomiting to pancreatitis, kidney injury and bowel blockage.¹⁸

Inflamed pancreas (pancreatitis)

In diabetes trials, pancreatitis was confirmed in 7 people on Ozempic and 3 on comparison medicines. That is 0.3 vs 0.2 cases per 100 patient-years (100 people taking it for a year).¹

Deadly forms have been seen with this class of medicine, including Ozempic.¹ The EU label calls it uncommon and says not to restart if pancreatitis is confirmed.²

Gallstones and gallbladder disease

Gallstones were reported in 1.5% on 0.5 mg and 0.4% on 1 mg, and in nobody on placebo.¹ The EU label lists gallstones as common.² A review of 76 trials found a 37% higher relative risk of gallbladder or bile-duct disease on GLP-1 medicines, higher with bigger doses, longer use and in weight-loss trials.⁸

Dehydration and kidney injury

Since launch, there have been reports of sudden kidney injury on semaglutide, some needing dialysis.¹ Most followed vomiting, diarrhoea or nausea that drained the body of fluid.¹

The EU label's warnings say dehydration "in rare cases" leads to worse kidney function.² The US label says to check the kidneys of people with these symptoms, mainly in the first weeks and at dose steps.¹

Low blood sugar (hypoglycaemia)

On Ozempic alone, lows were less likely. In a 30-week trial, 4% on 1 mg had a low with symptoms (common, in EU terms), and nobody had a severe one.¹

With a sulfonylurea (such as glimepiride or gliclazide), a low with symptoms hit 17% on 0.5 mg and 24% on 1 mg. Severe lows, needing another person's help, hit 0.8% and 1.2%.¹ The EU label calls low sugar with a sulfonylurea or insulin very common.²

With basal insulin, lows with symptoms hit 30% on 1 mg, against 15% on placebo. Severe lows hit 1.5% on 1 mg, and nobody on placebo.¹ The label says the doctor may lower the insulin or sulfonylurea dose.¹ See the type 2 diabetes path.

Food in the lungs during anaesthesia (aspiration)

Ozempic slows how fast the stomach empties. The US label notes reports since launch of food coming up into the lungs under general anaesthesia or deep sedation, even after fasting. It says there isn't enough data on whether stopping first helps.¹

In 2024, surgery, anaesthesia and gut societies said the risk is higher while the dose rises, or with stomach symptoms. If a slow stomach is suspected, the guidance suggests a liquid diet for at least 24 hours before.¹⁰ Tell every doctor before any surgery, endoscopy or sedation that you take Ozempic.¹

Other warnings on the label

• Severe stomach problems: reported in 0.4% on 0.5 mg and 0.8% on 1 mg, against none on placebo. Ozempic is not advised with severe gastroparesis (a very slow stomach).¹
• Blocked bowel and serious allergy (anaphylaxis, or swelling under the skin called angioedema) have been reported since launch.¹
• Thyroid warning: semaglutide caused thyroid C-cell tumours in rodents; whether it does in people is unknown. The US label rules it out if you or your family have had medullary thyroid cancer, or with MEN 2 (a rare inherited gland condition); tell your doctor if this applies.¹

What are the eye warnings on Ozempic?

There are two. Diabetic eye disease can get worse, mostly in people who already have it. A sudden loss of sight in one eye (NAION) is very rare.

Diabetic eye disease (retinopathy). In the 2-year SUSTAIN 6 trial, eye complications hit 3.0% on Ozempic and 1.8% on placebo.¹ In people who already had eye disease, it was 8.2% vs 5.2%. In those without, it was 0.7% vs 0.4%.¹ The EU label lists these eye complications as common.²

A 5-year trial of 1,500 people, called FOCUS, is testing this directly. It is due to finish in November 2027.⁹

Sudden vision loss (NAION). NAION is an eye-nerve condition that can cause painless loss of sight in one eye.² Europe's medicines regulator (EMA) began a review in January 2025, after mixed results from four observational studies.¹¹

In June 2025, the EMA called NAION a "very rare" side effect of Ozempic, Rybelsus and Wegovy. That means up to 1 in 10,000 people.¹² The EU label says large studies in people with type 2 diabetes suggest about double the risk. That is about 1 extra case per 10,000 person-years of use.²

The World Health Organization (WHO) issued its own alert on 27 June 2025.¹³ The US Ozempic label (May 2026) does not list NAION. It says to tell a doctor about any change in vision.¹ Rybelsus is the tablet form of the same medicine: see Is there an Ozempic tablet?

What has India's drug-safety programme said about Ozempic?

India's Pharmacovigilance Programme (PvPI) is watching semaglutide and asking people to report side effects. We found no Indian safety alert on it.

In April 2026, the Indian Pharmacopoeia Commission said it monitors GLP-1 reports through PvPI.¹⁴ In July 2026, PvPI urged doctors, pharmacists and patients to report any suspected reaction to semaglutide.¹⁵

We searched PvPI's list of drug safety alerts, from March 2016 to 27 July 2026. None of its 191 alerts names a GLP-1 medicine.¹⁶ That means no Indian alert yet, not proof of no problems.

Recalls. In July 2026, Dr Reddy's, Torrent and USV recalled some batches of generic semaglutide.²¹ Background: semaglutide generics in India.

Which Ozempic symptoms need help now?

Get help now for severe stomach pain that won't go away, vomiting you can't stop, a serious allergy, very low sugar or sudden sight loss.

Tell a doctor soon about pain in the upper stomach with fever, yellow skin or eyes, or pale clay-coloured stools. These can be gallbladder problems.¹ Also report a lump in the neck, a hoarse voice, or stomach problems that are severe or won't go away.¹

Drinking enough fluid lowers the chance of dehydration when you have stomach effects.¹

Questions people ask

Sources for these answers: the US and EU Ozempic labels, the Indian trials above and EMA reviews.^{1,2,4,5,12,19}

How we researched this

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