44% vs 16%adults reporting nausea on semaglutide against placebo, Wegovy label
Safety · Weight loss
Is semaglutide safe? What the FDA-approved label reports
The label does not say safe or unsafe. It reports common stomach effects, a set of less common serious ones, a boxed thyroid warning from animal studies, and groups who must not take it, while FDA warns separately about compounded and research-labeled versions.
On 2 November 2026, the Wegovy label reported nausea in 44% of adults on semaglutide against 16% on placebo, and severe stomach reactions in 4.1% against 0.9%. It carries a boxed warning on thyroid tumors seen in rodents, and FDA separately warns about compounded and research-labeled versions.
Source: the Wegovy label on DailyMed (version 19, effective 18 June 2026) and FDA's page on unapproved GLP-1 drugs (current as of 1 October 2026), read 2 November 2026.
The short version
44%nausea on semaglutideagainst 16% on placebo, adult weight-loss trials
4.1%severe stomach reactionsagainst 0.9% on placebo
Boxedthyroid tumor warningseen in rodents; human relevance not determined
990FDA reports, compoundedadverse events by 31 May 2026, likely underreported
Semaglutide safety: claims against the labelwhat gets said, and what the record shows, read 2 November 2026
They sayIt is just a bit of nausea.
Not that simple
Nausea was 44% against 16%, and severe stomach reactions 4.1% against 0.9%. The label also lists gallbladder disease, pancreatitis, kidney injury from dehydration, and a boxed thyroid warning. See the receipt
They sayCompounded semaglutide is the same drug, just cheaper.
Not an approval
FDA says compounded drugs are not FDA approved and not reviewed for safety, effectiveness or quality, and that some sold versions may use salt forms that are different active ingredients from the approved drug. See the receipt
They sayResearch-use vials are fine if you are careful.
Not cleared
FDA has warned companies selling semaglutide labeled "for research purposes" or "not for human consumption" with dosing instructions, and urges consumers not to buy them. See the receipt
What does this page read, and what does it leave out?
The Wegovy label is the main document read here, for both the injection and the newer tablet: the boxed warning, indications, contraindications, warnings, adverse reactions, interactions and special populations.[1] FDA's page on unapproved GLP-1 drugs and the MedlinePlus semaglutide injection page were also read in full.[2][3]
Read the reasoning
The efficacy sections and the published trial papers were not read, and neither were other semaglutide products' labels. Numbers below are adult data, and the label also covers adolescents from age 12. For trial depth and the compounding alert, see the semaglutide trial-record guide.
What is the boxed warning?
The label's boxed warning is about the thyroid: in rodents, semaglutide caused thyroid C-cell tumors at clinically relevant exposures, and it is unknown whether it does so in humans.[1] The label says the human relevance of the rodent finding has not been determined.
It is contraindicated in anyone with a personal or family history of medullary thyroid carcinoma, or with multiple endocrine neoplasia syndrome type 2.
Patients should be told the symptoms of thyroid tumors: a mass in the neck, trouble swallowing or breathing, and persistent hoarseness.
The label says routine calcitonin blood tests or thyroid ultrasound are of uncertain value for early detection.
MedlinePlus says in plain language to tell your doctor if you or anyone in your family has had thyroid tumors, thyroid cancer or MEN 2, and that your doctor will probably tell you not to use it.[3]
What are the common side effects?
The label pools three placebo-controlled adult trials of up to 68 weeks, with 2,116 adults on the approved injection and 1,261 on placebo.[1] Stomach reactions led the list, and any gastrointestinal reaction was reported by 73% on the drug against 47% on placebo.
Percent of adults reporting each reaction in Table 3 of the label: 2,116 on the approved injection against 1,261 on placebo, up to 68 weeks. Mean age 48, 71% female. Reactions were most frequent while the dose was being stepped up.
6.8% of adults on the drug stopped permanently because of a reaction, against 3.2% on placebo, and 4.3% stopped for a stomach reaction against 0.7%.
Hair loss was reported by 3.3% on the drug (4% of women, 0.9% of men) against 1% on placebo, and the label says it was associated with weight reduction.
The higher-dose injection raised altered skin sensations (dysesthesia) to 22% against 6% on the standard injection and 0.3% on placebo, and the tablet trial reported 5% against none.
What serious effects does the label list?
Several less common effects were more frequent on the drug than on placebo in the same trials.[1] The label says the gallbladder finding held up even after accounting for the amount of weight lost.
Percent of adults, from sections 5.3, 5.6 and 6.1 of the label. The label says gallbladder disease was higher on the drug even after accounting for the amount of weight lost.
Acute pancreatitis was confirmed in 4 adults on the drug (0.2 cases per 100 patient years) and 1 on placebo, and fatal and non-fatal cases have been reported after approval.
Acute kidney injury occurred in 7 adults on the drug and 4 on placebo, mostly with dehydration from vomiting or diarrhea, and some post-marketing cases needed dialysis.
Resting heart rate rose 1 to 4 beats per minute on average, and 26% on the drug had a rise of 20 or more at some visit against 16% on placebo.
In adults with type 2 diabetes, low blood sugar was reported in 6.2% against 2.5%, and the risk rises with insulin or sulfonylureas.
The drug delays stomach emptying, and rare post-marketing cases of aspiration under anesthesia or deep sedation have been reported.
What else does the label flag?
In the cardiovascular outcomes trial, with 8,803 adults on the drug, 16% on the drug and 8% on placebo stopped because of an adverse event.[1] Hip and pelvis fractures were reported in 1% of women on the drug against 0.2% on placebo, and in 2.4% of those aged 75 and over against 0.6%.
Serious allergic reactions, including anaphylaxis and angioedema, have been reported, and a prior serious reaction is a contraindication.
Lipase rose 39% and amylase 15 to 16% on average on the drug, which the label says has unknown significance without other signs of pancreatitis.
The label does not recommend it for severe gastroparesis, or alongside any other semaglutide or GLP-1 product.
Its revision notes show the suicidal behavior and ideation warning was removed in February 2026. The sections read do not say why, so this page makes no claim about it.
What does FDA say about compounded and research versions?
FDA says unapproved versions of GLP-1 drugs do not go through its review for safety, effectiveness and quality, and that compounded drugs should only be used when an approved drug cannot meet a patient's needs.[2] By 31 May 2026 it had received 990 adverse event reports for compounded semaglutide and more than 730 for compounded tirzepatide.
Counts of adverse event reports from FDA's page, current as of 1 October 2026. FDA says it is likely these are underreported, because most compounding pharmacies are not required to send them, and that it is not always possible to tell whether the drug caused an event.
FDA received multiple reports, some requiring hospitalization, that may be related to dosing errors with compounded injectable semaglutide, including patients measuring wrong doses themselves.
FDA says some compounded semaglutide may be sold as salt forms, which are different active ingredients from the approved drug, and it knows of no lawful basis for using them in compounding.
FDA warns of counterfeit Ozempic and of fraudulent labels naming pharmacies that did not make the product.
It has warned companies that sell semaglutide labeled "for research purposes" or "not for human consumption" with dosing instructions, and urges consumers not to buy them.
Questions the label raises
1. Any personal or family history of medullary thyroid cancer or MEN 2? That is a contraindication.
2. Past pancreatitis, gallstones, kidney or stomach-emptying problems? Say so first.
3. Diabetes medicines? The label flags low blood sugar with insulin or sulfonylureas.
4. A surgery or procedure planned? Tell the team you take it (the label flags aspiration risk).
5. Pregnancy plans? The label says to stop at least 2 months before a planned pregnancy.
6. Is the product FDA-approved? FDA lists red flags: deep discounts, no prescription, no doctor.
Both the label and FDA point people to the FDA's MedWatch program for reporting a suspected side effect or product problem.
Who should stay away?
The label lists two contraindications: a personal or family history of medullary thyroid carcinoma or MEN 2, and a prior serious allergic reaction to semaglutide or an ingredient.[1] It says the drug may cause fetal harm, that it should be stopped when pregnancy is recognized, and that it should be stopped at least 2 months before a planned pregnancy because of its long half-life.
Anyone with diabetic retinopathy should be monitored, since a 2-year trial in type 2 diabetes reported more retinopathy complications on semaglutide (3% against 1.8%).
The tablet's breastfeeding advice differs from the injection's, because the tablet contains an absorption aid found in breast milk.
The label supplies the first two boxes. The last two are where a prescriber earns the fee.
PubMed papers whose title or abstract mention semaglutide, weight loss and a harm word, counted 2 November 2026. A word match shows where the research is, not how often anything happens.
A word match includes papers that mention a harm only to rule it out, and it says nothing about how often anything happens.
It shows that the harms have been studied well beyond the label's tables, and that this page has not read that research.
How should you use this page?
If you are asking whether it is safeCommon effects are real, serious ones are rarerThe label reports high rates of stomach effects, rarer gallbladder, pancreas and kidney events, and a thyroid warning from animal studies. Weighing them against your own health is a prescriber's job.
If you are weighing a cheaper or research-labeled versionNot what the label describesThe label's numbers describe the approved product. FDA says unapproved versions are not reviewed and has warned about dosing errors, salt forms and counterfeits.
If you are losing hair or planning a childBoth are on the labelHair loss was reported in 3.3% against 1% and the label ties it to weight loss. For pregnancy plans, the label says to stop at least 2 months beforehand.
How this page was built
Method
The Wegovy label was downloaded from DailyMed's structured product label service on 2 November 2026 and sections 1 and 4 to 8 were read in full, as were FDA's page and the MedlinePlus page. Every rate is quoted from the label, and the report counts and warnings from FDA's page. Dose, strength and titration figures are left out on purpose, because this is not a dosing page.
Limits: one label from one maker, the efficacy and pharmacology sections not used, no published trial papers read, and no other GLP-1 product covered. The side-effect count is a word match and measures depth of record only (our grading rules are on the methodology page, and the evidence ladder shows how other topics compare). Nothing here is medical advice.
The exact query
Semaglutide side effects: (semaglutide[tiab] AND (obesity[tiab] OR "weight loss"[tiab] OR "weight management"[tiab] OR overweight[tiab])) AND (adverse[tiab] OR "side effect*"[tiab] OR pancreatitis[tiab] OR gallbladder[tiab] OR cholelithiasis[tiab] OR "thyroid cancer"[tiab] OR "gastrointestinal adverse"[tiab] OR "adverse event*"[tiab])
References
abcdef DailyMed (National Library of Medicine). Wegovy (semaglutide) injection and tablets label, Novo Nordisk, version 19, effective 18 June 2026. Sections 1 and 4 to 8 were read. dailymed.nlm.nih.gov, read 2 November 2026.
ab FDA. FDA's concerns with unapproved GLP-1 drugs used for weight loss (content current as of 1 October 2026). fda.gov, read 2 November 2026.
ab MedlinePlus (National Library of Medicine). Semaglutide injection: drug information, last revised 15 May 2026. medlineplus.gov, read 2 November 2026.
↑ PubMed search for semaglutide with obesity, weight loss, weight management or overweight, narrowed to papers that mention adverse or side effects, pancreatitis, gallbladder disease, thyroid cancer or gastrointestinal adverse events in the title or abstract; the query is printed in the method section. pubmed.ncbi.nlm.nih.gov, read 2 November 2026.
↑ National Library of Medicine. MeSH publication type: Randomized Controlled Trial. ncbi.nlm.nih.gov.
FAQ
Is semaglutide safe?
The Wegovy label does not say safe or unsafe. It reports nausea in 44% of adults on semaglutide against 16% on placebo, severe stomach reactions in 4.1% against 0.9%, more gallbladder disease, a boxed warning on thyroid tumors seen in rodents, and two contraindications. A prescriber weighs these against your history.
What are the most common semaglutide side effects?
In the label's adult weight-loss trials: nausea (44%), diarrhea (30%), vomiting (24%), constipation (24%), abdominal pain (20%), headache (14%) and fatigue (11%), against lower rates on placebo. They were most frequent while the dose was being increased.
Does semaglutide cause thyroid cancer?
The label says semaglutide caused thyroid C-cell tumors in rodents at clinically relevant exposures, and that it is unknown whether it causes them, including medullary thyroid carcinoma, in humans. It is contraindicated in people with a personal or family history of that cancer or MEN 2.
Does semaglutide cause hair loss?
The label reports hair loss in 3.3% of adults on semaglutide (4% of women, 0.9% of men) against 1% on placebo, and says hair loss was associated with weight reduction.
Is compounded semaglutide safe?
FDA says compounded drugs are not FDA approved and are not reviewed for safety, effectiveness or quality. By 31 May 2026 it had received 990 adverse event reports for compounded semaglutide, and it has warned about dosing errors, salt forms and counterfeit products.
Bottom line
The Wegovy label reports high rates of stomach effects, rarer gallbladder, pancreas and kidney events, a boxed thyroid warning from animal studies, and firm limits on who should take it. FDA adds that unapproved and research-labeled versions are not what those numbers describe. Hold any claim of "just nausea" or "same drug, cheaper" up against that wording, then take the specifics to a prescriber.
How do I cite this page?
Cite the page and the date its figures were read. Every count here is a count of records matching a published query on the day it was read, so it can move; the method box on this page prints the query so you can re-run it.
APA
Whitepill editorial desk. (2026, November 2). Is semaglutide safe? What the FDA-approved label reports. Whitepill. https://whitepill.dev/articles/is-semaglutide-safe-what-the-fda-label-reports
BibTeX
@online{whitepill_is_semaglutide_safe_what, author = {{Whitepill editorial desk}}, title = {Is semaglutide safe? What the FDA-approved label reports}, year = {2026}, month = nov, url = {https://whitepill.dev/articles/is-semaglutide-safe-what-the-fda-label-reports}, note = {Last modified 2026-11-03}
}
Published 2 November 2026. Last modified 3 November 2026. Where a figure rests on secondary reporting, the page says so; do not present that as a primary source.
What has changed on this page?
fix Fixed chart labels that were cut off on the left on narrow phone screens. The label column now widens to fit the longest label. No figure or finding changed.
new Published. Rates are quoted from the Wegovy label on DailyMed (version 19, effective 18 June 2026), the FDA page on unapproved GLP-1 drugs and MedlinePlus, read on 2 November 2026.