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Wegovy side effects, as its own label reports them

Nausea is the side effect Wegovy’s label reports most often: 44 in every 100 adults on the 2.4 mg weekly shot, against 16 in every 100 on placebo.

Source: Read from the Wegovy label, revision 06/2026

What matters first

Highest listed reaction
Nausea: 44% in Wegovy 2.4 mg
Distinct reactions listed
19
Warnings to watch
10
Boxed warning
The boxed warning: thyroid tumors in rodents

Medically reviewed by Jennifer Montecillo, MD · non-practicing medical reviewerReviewed 2026-08-12every number here is sourced

The 2.4 mg weekly shot, in the weight trials

Read the placebo column first. Nearly everything below happens to some people on a dummy injection too, and the gap between the columns is the part the drug is answerable for.

Trial armsPlacebo: n = 1,261Wegovy 2.4 mg: n = 2,116

The 2.4 mg weekly shot, in the weight trials
Side effectPlaceboWegovy 2.4 mg
Nausea16%44%
Diarrhea16%30%
Vomiting6%24%
Constipation11%24%
Belly painGroups upper, lower and general belly pain, tenderness and discomfort10%20%
Headache10%14%
TirednessGroups fatigue and weakness5%11%
Indigestion3%9%
Dizziness4%8%
Bloating5%7%
BurpingThe label prints the placebo figure as less than 1%1%7%
Low blood sugar, in type 2 diabetesBlood sugar under 54 mg/dL, in people not on insulin2%6%
Wind4%6%
Stomach bug4%6%
Acid reflux3%5%
Stomach lining irritation1%4%
Viral stomach bug3%4%
Hair loss1%3%
Odd skin sensationsGroups tingling, burning, oversensitive skin and skin pain1%2%
Who was in the trials
2,116 adults with obesity or overweight took the 2.4 mg shot across three placebo-controlled trials. 1,261 took placebo. The average age was 48 and 71% were women.
How long
Up to 68 weeks, then 7 weeks off the drug
What made the table
Everything reported by 2 in 100 people or more, and more often than on placebo
Who stopped
6.8 in every 100 people stopped for good because of a side effect, against 3.2 on placebo. The three reasons named most often were nausea, vomiting and diarrhea.

The 7.2 mg weekly shot, against 2.4 mg and against placebo

Trial armsPlacebo: n = 303Wegovy 2.4 mg: n = 304Wegovy 7.2 mg: n = 1,311

The 7.2 mg weekly shot, against 2.4 mg and against placebo
Side effectPlaceboWegovy 2.4 mgWegovy 7.2 mg
Nausea13%35%39%
Vomiting6%16%22%
Odd skin sensationsGroups tingling, burning, oversensitive skin and skin pain0%6%22%
Constipation8%19%20%
Belly pain7%9%12%
Tiredness5%9%11%
Headache7%8%9%
Dizziness1%5%6%
Hair loss1%3%6%
Wind2%2%4%
Who was in the trials
1,311 adults with obesity took 7.2 mg in two trials. 304 took 2.4 mg and 303 took placebo. Average age 49, average BMI 39.5.
How long
72 weeks
What made the table
Everything reported by 2 in 100 people or more, and more often than on both 2.4 mg and placebo
Who stopped
5 in every 100 stopped for good on 7.2 mg, 5 on 2.4 mg and 2 on placebo. Stomach and gut problems were the reason in 3, 3 and 0.3 respectively.

The boxed warning: thyroid tumors in rodents

Wegovy carries the strongest warning the FDA uses. Rodents given semaglutide grew thyroid C-cell tumors. Whether the same happens in people is unknown. The label rules the drug out for anyone with a personal or family history of medullary thyroid cancer, and for anyone with the inherited condition MEN 2.

What does the label tell prescribers to watch for?

These sit above the table in the label, in the section reserved for the problems that are rare but matter most.

Warnings and precautions from the Wegovy FDA label
WarningWhat this label says about it
PancreatitisThe label tells prescribers to stop the drug where it is suspected.
Gallbladder diseaseGallstones were reported by 1.6 in 100 on the shot and 0.7 on placebo.
Low blood sugarMainly in people also taking insulin or a sulfonylurea.
Kidney injuryUsually after fluid loss from being sick or having diarrhea.
Severe stomach and gut problemsReported by 4.1 in 100 on the shot against 0.9 on placebo, and 2 in 100 on the tablet against none. The label says Wegovy is not recommended where gastroparesis is severe.
Serious allergic reactionsIncluding swelling of the face and throat.
Diabetic eye diseaseFast improvement in blood sugar can make existing eye damage worse.
A faster resting heart rateThis warning is Wegovy’s own. Resting heart rate rose 1 to 4 beats a minute on average, and 26 in 100 adults had a jump of 20 beats or more at some visit, against 16 on placebo.
Breathing in stomach contents under anestheticThe label says food can stay in the stomach longer than expected.
Sharing a penThe label says a FlexTouch pen must never be shared, even with a fresh needle.

What have people actually reported about Wegovy?

21,044 reports naming Wegovy have reached the FDA’s public database. A report is not proof the drug caused anything, and there is no way to know how many people took it.

Most reported terms for Wegovy in openFDA FAERS, retrieved 2026-08-17
Most reportedReportsShare of Wegovy reports
Nausea2,861 reports14% of Wegovy reports
Vomiting1,839 reports8.7% of Wegovy reports
Diarrhea1,156 reports5.5% of Wegovy reports
Off label use1,119 reports5.3% of Wegovy reports
Weight increased1,015 reports4.8% of Wegovy reports
Constipation1,011 reports4.8% of Wegovy reports
Weight loss poor921 reports4.4% of Wegovy reports
Fatigue892 reports4.2% of Wegovy reports
Device malfunction822 reports3.9% of Wegovy reports
Device leakage795 reports3.8% of Wegovy reports

Nausea leads the Wegovy report pile too, which is the rare case of the trials and the reports agreeing on what sits at the top.

Two things in the top ten have nothing to do with the body: reports about the pen itself, and reports that the drug did not work. Neither is a side effect. Both are things people file when a product does not behave as expected.

  • There is no denominator. FAERS counts reports that were filed. It does not count the people who took the drug, so there is no bottom half to the fraction. Any figure on this page that looks like a percentage is a share of this drug’s reports — never a share of the people who took it.
  • A report is not proof the drug did it. FDA does not require a reporter to establish cause. A report says somebody noticed something and thought the drug was worth naming. Some of these events were caused by the drug, some were caused by the illness it was prescribed for, and some were coincidence — FAERS does not separate them.
  • A bigger number can just mean a more-prescribed drug. More reports can simply mean that more people use the drug, that it is newer, or that it receives more news and legal attention. Raw report totals do not tell you which drug is safer.
  • The same event can be counted twice. One event can reach FAERS through more than one channel — the patient, the prescriber and the manufacturer can all file. FDA does not guarantee that the public files are de-duplicated.
  • Retrieved 2026-08-17 from https://api.fda.gov/drug/event.json. FDA disclaimer: Do not rely on openFDA to make decisions regarding medical care. While we make every effort to ensure that data is accurate, you should assume all results are unvalidated. We may limit or otherwise restrict your access to the API in line with our Terms of Service.
4Interpret the pageDose patterns, same-drug context, and where the evidence continues

The 7.2 mg dose brings something the lower doses barely show

Odd skin sensations went from 6 in 100 people on 2.4 mg to 22 in 100 on 7.2 mg. On placebo it was almost nobody.

The label describes it as tingling, burning, oversensitive skin or skin pain, and says it got more common as the dose and the drug level in the blood went up. Of the 288 people it happened to on 7.2 mg, 2 in 100 stopped for good, 8 paused, and 23 dropped to a lower dose. About 18 in every 100 had not recovered by the end of the trial. Of 38 people who went back up to 7.2 mg after recovering, 17 got it again.

This is the clearest reason not to read the 7.2 mg dose as simply more of the same drug.

The pill has its own trial and its own numbers

204 adults took the 25 mg Wegovy tablet for up to 64 weeks. 6.9 in every 100 stopped for good because of a side effect, against 5.9 on placebo.

The label says the kinds of side effects and how often they came up were much like the shot. The one figure it prints separately for the tablet is odd skin sensations, at 5 in 100 people against none on placebo. It also reports gallstones in 2.5 in 100 on the tablet against 1 on placebo.

Why do Wegovy and Ozempic report different numbers for the same drug?

Both are semaglutide. The percentages differ because the trials behind them differ, not because one product is gentler than the other.

Each label opens its table with the same warning: rates from one drug’s trials cannot be set against another’s. That holds here even though the drug substance is identical. The two sets of trials enrolled different people. They ran to different doses. And they used different cut-offs for what got printed at all.

The Ozempic side-effect table in full

Where to read next

Two pages carry the parts this one leaves out.

Questions readers ask

What are long-term side effects of Wegovy?

The longest stretch the label reports is the trials themselves: up to 68 weeks on the drug, then seven weeks off it. Nothing on the label runs to years.

One long-run finding does stand out. Of those who got odd skin sensations on 7.2 mg, about 18 in every 100 had not recovered when the trial ended.

How much weight can you lose in 3 months with Wegovy?

No cited trial reports a three-month figure, and a 72-week average cannot be worked backward into one.

Three months is also mostly ladder rather than treatment. The label steps the dose every four weeks. Week twelve is still two steps below the 2.4 mg the results were measured at.

What medications should be avoided with Wegovy?

The label does not print a list of medicines to avoid. It names one combination to watch: insulin or a sulfonylurea, where low blood sugar becomes more likely.

It also warns that food can stay in the stomach longer than expected, which is why an anesthetist needs to be told before a procedure. Anything beyond that depends on the rest of a person’s list, which only their prescriber can see.

What's the worst day on Wegovy?

There is no published worst day. The label’s table counts how many of 2,116 adults reported each effect over the whole trial, and never records when.

The figures themselves are the useful part. Nausea reached 44 of every 100 people on 2.4 mg, against 16 on placebo. Diarrhea followed at 30, then vomiting and constipation at 24.

1primary source, each with the day we read it — open the documents used on this page

Wegovy is a registered trademark of its manufacturer. This page is not written, reviewed or endorsed by them. It reports figures from a public FDA label and from the FDA’s own report database, and it is not medical advice.

Beyond the Wegovy reaction table