Key facts
- In OASIS 4, the trial behind the Wegovy pill, nausea affected 46.6% of people on 25 mg tablets against 18.6% on placebo, and vomiting 30.9% against 5.9%.[4]
- Gastrointestinal adverse events overall were reported by 74.0% on the pill against 42.2% on placebo; severe GI reactions by 2% against 0%.[3][1]
- 6.9% stopped the Wegovy pill because of adverse reactions, against 5.9% on placebo; GI reactions caused 3.4% against 2%.[1]
- The label carries a boxed warning on thyroid C-cell tumours: semaglutide caused them in mice and rats, and the pill is contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2.[1]
- In a drug interaction study, oral semaglutide raised levothyroxine exposure by 33%, so the label advises monitoring oral medicines taken alongside it.[1]
Most Common Wegovy Pill Side Effects
Nausea is the most common Wegovy pill side effect: 95 of 204 people (46.6%) on 25 mg tablets reported it in OASIS 4, against 19 of 102 (18.6%) on placebo, over 64 weeks of treatment plus 7 weeks of follow-up.[4]
| Adverse event | Wegovy tablets 25 mg (n = 204) | Placebo (n = 102) |
|---|---|---|
| Nausea | 46.6% | 18.6% |
| Vomiting | 30.9% | 5.9% |
| Constipation | 20.1% | 9.8% |
| Indigestion (dyspepsia) | 18.1% | 8.8% |
| Diarrhoea | 17.6% | 8.8% |
| Headache | 11.8% | 8.8% |
| Belching (eructation) | 10.3% | 2.0% |
| Upper abdominal pain | 8.8% | 2.0% |
| Acid reflux (GORD) | 7.8% | 4.9% |
| Abdominal pain | 7.4% | 3.9% |
| Fatigue | 7.4% | 1.0% |
| Decreased appetite | 6.9% | 1.0% |
| Hair loss (alopecia) | 6.4% | 2.0% |
| Dizziness | 5.4% | 1.0%[4] |
ClinicalTrials.gov NCT05564117 posted adverse events, 204 on 25 mg tablets vs 102 on placebo.
The FDA label does not print a separate side-effect table for the tablets. It says that in the 25 mg tablet trial "the types and frequency of common adverse reactions were similar" to the Wegovy 2.4 mg injection table, where nausea was 44% against 16% on placebo.[1] The label adds one tablet-specific figure: altered skin sensation (dysaesthesia) in 5% on the pill and in no one on placebo.[1] The NEJM paper reports gastrointestinal adverse events in 74.0% against 42.2%.[3] Wegovy tablets were approved on 22 December 2025 under NDA 218316, and the figures here come from the label revised 06/2026.[2] For how the pill works and what it is approved for, see Wegovy pill.
The Wegovy pill is not sold in this shop, and this page is not a guide to obtaining it. It summarises the FDA label and published trial data for reference.
When Do Wegovy Pill Side Effects Start and How Long Do They Last?
GI side effects are most likely during the 90-day dose escalation from 1.5 mg to 4 mg, 9 mg and then 25 mg, which the label sets in 30-day steps specifically to reduce gastrointestinal adverse reactions.[1]
- Escalation is the GI-risk window. In the Wegovy weight trials, GI reactions "were most frequently reported during dosage escalation".[1]
- Slowing down is allowed. If a dose is not tolerated during escalation, the label says to consider delaying the next step. For the full schedule, see Wegovy pill dosage.[1]
- If 25 mg is not tolerated. The label suggests considering a switch to Wegovy injection 1.7 mg once weekly.[1]
- The drug lingers. Semaglutide has an elimination half-life of about 1 week and stays in the circulation for about 5 to 7 weeks after the last 25 mg oral dose.[1]
- Kidney check during escalation. The label advises monitoring kidney function in people with vomiting, diarrhoea or nausea that could cause dehydration, especially while starting and raising the dose.[1]
The label does not give a typical duration in days or weeks for any individual side effect of the tablets. The Medication Guide tells patients to contact their healthcare provider about nausea, vomiting or diarrhoea that does not go away.[1]
How Many People Stop the Wegovy Pill Because of Side Effects?
6.9% of people on Wegovy 25 mg tablets permanently stopped because of adverse reactions in OASIS 4, against 5.9% on placebo, and GI reactions were the most common reason (3.4% against 2%).[1]
| Measure | Wegovy tablets 25 mg | Placebo |
|---|---|---|
| Stopped due to adverse reactions (section 6.1) | 6.9% | 5.9%[1] |
| Stopped due to GI adverse reactions | 3.4% | 2%[1] |
| Stopped study drug for any reason | 18% | 25.5%[1] |
| Severe GI adverse reactions | 2% | 0%[1] |
| Any serious adverse event (counts) | 8 of 204 (3.9%) | 9 of 102 (8.8%)[4] |
Section 14 of the same label gives the adverse-reaction discontinuation rate on the pill as 6.8%, a small rounding difference from the 6.9% in section 6.1.[1] More people stopped placebo than the pill for any reason, which the label figures show but do not explain.[1]
Wegovy Pill Boxed Warning: Thyroid C-Cell Tumours
Yes, the Wegovy pill has a boxed warning: semaglutide caused dose- and duration-dependent thyroid C-cell tumours in mice and rats at clinically relevant exposures, and it is unknown whether it does so in humans.[1]
- Contraindication. Wegovy must not be used by people with a personal or family history of medullary thyroid carcinoma (MTC) or with Multiple Endocrine Neoplasia syndrome type 2 (MEN 2).[1]
- Symptoms to report. The label lists a mass in the neck, difficulty swallowing, shortness of breath and persistent hoarseness.[1]
- Class evidence. MTC cases have been reported after marketing with liraglutide, another GLP-1 receptor agonist; the reports cannot establish or exclude a causal link.[1]
- Screening. Routine calcitonin tests or thyroid ultrasound are of uncertain value for early detection; people with MTC usually have calcitonin above 50 ng/L.[1]
- Second contraindication. A prior serious hypersensitivity reaction to semaglutide or any excipient in the tablets or injection.[1]
Serious Warnings and Precautions for the Wegovy Pill
The label lists 11 warnings and precautions, 10 of which apply to the tablets; in the tablet trial, gallstones were reported by 2.5% on the pill against 1% on placebo.[1]
| Warning (label section) | What the label says | Figure given |
|---|---|---|
| Thyroid C-cell tumours (5.1) | Boxed warning; contraindicated with MTC or MEN 2 | Rodent tumours at clinical exposures[1] |
| Acute pancreatitis (5.2) | Stop if suspected; persistent or severe abdominal pain, sometimes radiating to the back | Injection trials: 4 adjudicated cases (0.2 per 100 patient-years) vs 1[1] |
| Acute gallbladder disease (5.3) | Investigate if gallstones are suspected; risk higher even after accounting for weight loss | Tablets: gallstones 2.5% vs 1%[1] |
| Hypoglycaemia (5.4) | Risk rises with insulin or a sulfonylurea; consider lowering their dose | No tablet rate given[1] |
| Acute kidney injury from dehydration (5.5) | Monitor kidney function if GI losses could dehydrate, especially when starting or raising the dose | Injection trials: 0.4 vs 0.2 cases per 100 patient-years[1] |
| Severe GI reactions (5.6) | Not recommended in severe gastroparesis | Tablets: 2% vs 0%[1] |
| Hypersensitivity (5.7) | Anaphylaxis and angioedema reported; stop and seek care | No tablet rate given[1] |
| Diabetic retinopathy in type 2 diabetes (5.8) | Rapid glucose improvement can temporarily worsen retinopathy; monitor those with a history | Diabetes tablet trial: moderate-severe events 1.3% (9 mg) and 1.9% (25 mg)[1] |
| Heart rate increase (5.9) | Monitor; stop if resting heart rate stays raised | Injection: +1 to 4 bpm; "similar" with tablets[1] |
| Pulmonary aspiration under anaesthesia (5.10) | Tell the care team before surgery or deep sedation | Rare postmarketing reports with GLP-1 drugs[1] |
- The 11th warning, never sharing a Wegovy FlexTouch pen, applies to the injection only.[1]
- The suicidal behaviour and ideation warning was removed from the label in January 2026, per its Recent Major Changes list. In OASIS 4, one serious suicidal ideation event was posted, in the placebo group.[1][4]
- Stop Wegovy at least 2 months before a planned pregnancy because of semaglutide’s long half-life; breastfeeding is not recommended on the tablets because of the absorption enhancer SNAC.[1]
- Wegovy tablets have not been studied for weight reduction in adults with type 2 diabetes, and their safety is not established in under-18s.[1]
- Postmarketing reports with semaglutide include ileus, intestinal obstruction, severe constipation with faecal impaction and acute kidney injury.[1]
Other Side Effects on the Wegovy Label
The label applies several injection-trial findings to the tablets too, including low blood pressure in 1.3% against 0.4% on placebo and fainting (syncope) in 0.8% against 0.2%.[1]
- Taste change (dysgeusia). 1.7% against 0.5% in the adult weight trials.[1]
- Hair loss. Linked to weight reduction; 3.3% on Wegovy 2.4 mg injection (4% of women, 0.9% of men) against 1% on placebo. In OASIS 4, alopecia was posted for 6.4% on the pill against 2.0%.[1][4]
- Pancreatic enzymes. Mean amylase rose 15% to 16% and lipase 39%; the significance without pancreatitis symptoms is unknown.[1]
- Allergic reactions and antibodies. Allergic reactions occurred in 16% of people who developed anti-semaglutide antibodies against 7% of those who did not.[1]
- Fractures. In the cardiovascular outcomes trial, hip and pelvis fractures were more frequent on Wegovy injection in women (1% against 0.2%) and in people aged 75 and older (2.4% against 0.6%).[1]
Wegovy Pill Drug Interactions
In a drug interaction study with semaglutide tablets, total levothyroxine exposure (AUC) rose 33% (90% CI 1.25 to 1.42) after a single 600 mcg dose, with peak level unchanged.[1]
| Medicine or group | Label advice | Reason |
|---|---|---|
| Levothyroxine | Monitor the effect of oral medicines taken with Wegovy | Total thyroxine AUC up 33% with oral semaglutide[1] |
| Narrow therapeutic index oral drugs | Consider more clinical or laboratory monitoring | Slower stomach emptying may change absorption[1] |
| Any other oral medicine | Wait at least 30 minutes after the tablet before taking it | Dosing instruction for the tablets[1] |
| Insulin or sulfonylureas | Consider lowering their dose when starting | Higher hypoglycaemia risk[1] |
| Other semaglutide products or GLP-1 receptor agonists | Not recommended together | Limitation of use[1] |
| Omeprazole | No adjustment stated | No clinically significant change in semaglutide levels[1] |
The tablet is taken on an empty stomach in the morning with up to 4 ounces of water and no other liquids, which is why other oral medicines wait 30 minutes.[1] Rybelsus is a separate oral semaglutide for type 2 diabetes with its own label; see what is Rybelsus.
Wegovy Pill vs Foundayo Nausea
Nausea was posted for 46.6% on the Wegovy pill in OASIS 4 against 18.6% on placebo, while the Foundayo label reports 26%, 34% and 35% on 5.5, 9 and 17.2 mg against 10% on placebo, but these come from different trials and are not directly comparable.[4][5]
Wegovy pill: OASIS 4, 71 weeks, all adverse events (ClinicalTrials.gov). Foundayo: pooled ATTAIN-1 and ATTAIN-2, up to 72 weeks, adverse reactions (FDA label Table 1).
- Different trials. OASIS 4 enrolled 307 people without diabetes; the Foundayo pool combined 3,155 treated people from two trials, one of them in type 2 diabetes.[3][5]
- Different counting. The Wegovy pill figures are all posted adverse events; the Foundayo label table counts adverse reactions in at least 5% and more common than placebo.[4][5]
- Different placebo rates. Placebo nausea was 18.6% in OASIS 4 and 10% in the Foundayo pool, so the gap over placebo is a fairer view than the raw figure.[4][5]
- No head-to-head weight trial of the two pills was found. For the full comparison, see Foundayo vs Wegovy pill, Foundayo side effects and GLP-1 pills.
Frequently Asked Questions
What are the most common side effects of the Wegovy pill?
In OASIS 4, the most common were nausea (46.6% against 18.6% on placebo), vomiting (30.9% against 5.9%), constipation (20.1% against 9.8%), indigestion (18.1% against 8.8%) and diarrhoea (17.6% against 8.8%). Headache, belching, abdominal pain, acid reflux, fatigue, decreased appetite, hair loss and dizziness were also more common than on placebo.
Does the Wegovy pill cause nausea?
Yes. Nausea was posted for 95 of 204 people (46.6%) on 25 mg tablets in OASIS 4, against 19 of 102 (18.6%) on placebo. The label says the tablet’s common side effects are similar in type and frequency to the Wegovy injection, where nausea was 44% against 16%.
How long do Wegovy pill side effects last?
The label does not give a duration in days or weeks. GI side effects were most often reported during dose escalation, the first 90 days for the tablets. Semaglutide has a half-life of about 1 week and stays in the body for about 5 to 7 weeks after the last 25 mg dose.
Does the Wegovy pill have a boxed warning?
Yes. The boxed warning covers thyroid C-cell tumours, which semaglutide caused in mice and rats. The human relevance is not known. The pill is contraindicated in people with a personal or family history of medullary thyroid carcinoma or with MEN 2.
Are oral Wegovy side effects different from the injection?
The label says the types and frequency of common adverse reactions with 25 mg tablets were similar to the 2.4 mg injection. Tablet-specific figures it does give include severe GI reactions in 2% against 0%, gallstones in 2.5% against 1%, and altered skin sensation in 5% against 0%.
Does the Wegovy pill interact with levothyroxine?
Yes. In a drug interaction study, oral semaglutide raised total levothyroxine exposure by 33%. The label advises monitoring the effects of oral medicines taken with Wegovy, and more monitoring for drugs with a narrow therapeutic index.
Sources
- FDA. WEGOVY (semaglutide) injection and tablets prescribing information, revised 06/2026 (NDA 218316, supplement 7, Reference ID 5819850), checked 8 Nov 2026
- FDA. Drugs@FDA, NDA 218316 (Wegovy tablets) approval history, checked 8 Nov 2026
- Wharton S, et al. Oral semaglutide at a dose of 25 mg in adults with overweight or obesity (OASIS 4). N Engl J Med 2025;393(11):1077-1087. DOI 10.1056/NEJMoa2500969
- ClinicalTrials.gov NCT05564117 (OASIS 4), posted results, adverse events module, checked 8 Nov 2026
- FDA. FOUNDAYO (orforglipron) tablets prescribing information, revised 07/2026 (NDA 220934, supplement 3), checked 8 Nov 2026
For research use only. Not for human or veterinary consumption. This guide summarises published research for information only. It is not medical advice and does not describe any use of products sold on this site.