Wegovy Tablet Side Effects: What to Expect

Wegovy tablet side effects are an important consideration for anyone starting or switching to the oral form of semaglutide, which received MHRA authorisation in June 2026. Like the injectable version, the Wegovy 25 mg tablet contains semaglutide, a GLP-1 receptor agonist that slows gastric emptying and reduces appetite. Most side effects are gastrointestinal and tend to improve as the body adjusts, but some require prompt medical attention. This article explains what to expect, how long side effects typically last, which symptoms need urgent review, and who may be at greater risk.

Is Wegovy a tablet or an injection?

Wegovy is available in the UK as both a weekly subcutaneous injection and, since 11 June 2026, an oral 25 mg tablet authorised by the MHRA; both forms contain semaglutide.

Wegovy is available in the UK in two forms: a subcutaneous injection and, since 11 June 2026, an oral tablet authorised by the MHRA. The injectable form of Wegovy is a subcutaneous (under the skin) weekly injection containing semaglutide, delivered using a multi-dose FlexTouch pen. The oral tablet form, Wegovy 25 mg, received MHRA authorisation on 11 June 2026 and is a distinct product from Rybelsus, with its own licensed posology; it should not be reviewed against the Rybelsus prescribing information.^[6][1]

Both forms contain semaglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist. Semaglutide works by mimicking the GLP-1 hormone, which is released naturally after eating. It slows gastric emptying, reduces appetite, and increases feelings of fullness, supporting weight management alongside a reduced-calorie diet and increased physical activity.

The injectable Wegovy is available in dose strengths from 0.25 mg up to 2.4 mg weekly, with a gradual escalation schedule to help the body adjust. A higher maintenance dose of 7.2 mg has also received MHRA approval, extending the options available. Because the two presentations differ in their route of administration and dose schedules, a prescriber should guide which form is appropriate for an individual's circumstances. Where side effect profiles differ between the two forms, this is noted in the relevant sections below.

Bolt Pharmacy is a GPhC-registered UK online pharmacy offering online weight-management consultations, with prescriber review and pharmacist support, where a range of treatment options may be considered.

What side effects can Wegovy cause?

Wegovy most commonly causes gastrointestinal side effects including nausea, vomiting, diarrhoea, and constipation, which are most pronounced during dose escalation.

Wegovy (semaglutide) most commonly causes gastrointestinal side effects, particularly during the dose escalation phase. These are documented in the product's Summary of Product Characteristics (SmPC) and include:

• Nausea (very common, affecting more than 1 in 10 people)

• Vomiting

• Diarrhoea

• Constipation

• Abdominal pain or discomfort

• Indigestion and bloating

• Burping

• Fatigue

• Headache

• Dizziness

These effects arise largely because semaglutide slows the movement of food through the stomach and gut. When the stomach empties more slowly, the body can take time to adapt, which is why symptoms tend to be most pronounced when starting treatment or after each dose increase.

Less commonly, people may experience changes in heart rate and gallbladder-related problems, including gallstones; significant weight loss of any cause can increase the risk of gallstone formation.^[11][1] Hair thinning has been reported by some people using Wegovy; the extent to which this is a direct pharmacological effect of semaglutide or a consequence of rapid weight loss is uncertain, and patients should discuss any concerns with their prescriber. For those using the injectable form, injection-site reactions such as redness, bruising, or mild discomfort at the site of administration may also occur.

Acute pancreatitis has been reported with semaglutide, including post-marketing reports of necrotising pancreatitis and reports with a fatal outcome.^[12][1] The UK SmPC does not quantify the risk magnitude, so it is not possible to describe it as small or rare. Patients should be aware of the warning signs and seek prompt medical advice if they develop persistent, severe abdominal pain.

Suspected side effects from Wegovy can be reported to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk.

Which side effects are serious enough to see a doctor about?

Persistent severe abdominal pain, signs of gallbladder problems, rapid heartbeat, allergic reactions, and significant mood changes all require prompt medical attention; call 999 for anaphylaxis.

Certain side effects associated with Wegovy require prompt medical attention and should not be managed at home without professional guidance. Contact your GP or call NHS 111 if you experience any of the following:

• Persistent or severe abdominal pain, particularly pain that radiates to the back, which may indicate pancreatitis

• Persistent vomiting that prevents you from keeping fluids down, raising the risk of dehydration

• Signs of gallbladder problems, such as upper right abdominal pain, fever, or jaundice (yellowing of the skin or eyes)

• Rapid or irregular heartbeat that is new or unexplained

• Significant mood changes, low mood, or thoughts of self-harm (contact your GP or call NHS 111 promptly; call 999 if you or someone else is in immediate danger)

• Allergic reactions, including swelling of the face, lips, tongue or throat, difficulty breathing, or a widespread rash

For a severe allergic reaction (anaphylaxis) with difficulty breathing or collapse, call 999 immediately.

People with pre-existing diabetic eye disease should be aware that rapid improvement in blood glucose control can be associated with transient worsening of diabetic retinopathy. This is particularly relevant for those with pre-existing proliferative or pre-proliferative retinopathy, and any new or worsening visual symptoms should be reported to a GP or ophthalmologist without delay.

The UK SmPC for Wegovy does not list medullary thyroid carcinoma or multiple endocrine neoplasia type 2 as contraindications; these warnings appear in US labelling and do not form part of the UK prescribing information. The only contraindication listed in the UK SmPC is hypersensitivity to semaglutide or any excipient. If you have concerns about your thyroid or any new neck symptoms, discuss these with your GP.

How long do Wegovy side effects usually last?

Most gastrointestinal side effects are temporary and improve as the body adjusts; nausea typically subsides within a few weeks of each dose increase.

Most gastrointestinal side effects of Wegovy are temporary and tend to improve as the body adjusts to the medicine. The dose escalation schedule for Wegovy is designed specifically to minimise side effects by introducing the medicine gradually, allowing the gut time to adapt before the dose is increased further.

For many people, nausea is most noticeable in the first few weeks after a dose increase and then gradually subsides. Eating smaller meals, avoiding high-fat or very rich foods, and not lying down immediately after eating can all help to reduce the severity of nausea during this period. Staying well hydrated is particularly important if diarrhoea or vomiting occurs; if you are unable to keep fluids down, seek medical advice promptly, as persistent vomiting or diarrhoea can lead to dehydration.

Side effects that persist beyond several weeks at a stable dose, or that are severe enough to interfere significantly with daily life, should be discussed with a prescriber. In some cases, remaining at a lower dose for longer before escalating, or adjusting dietary habits, can make treatment more tolerable. A prescriber may also consider whether the side effect profile warrants a change in treatment.

Hair thinning, if it occurs, is generally reported during periods of weight loss; the extent to which it is a direct effect of semaglutide or related to weight loss itself is uncertain, and it should be discussed with a prescriber if it is a concern. Injection-site reactions, where relevant to the injectable form, are usually mild and short-lived, resolving within a few days of each injection.

Who is more likely to experience side effects on Wegovy?

People with severe gastrointestinal disease, a history of pancreatitis, or those taking blood-glucose-lowering medicines are at higher risk and require careful prescriber review before starting Wegovy.

People who are more sensitive to gastrointestinal disturbance in general, or who have a history of conditions such as severe gastroparesis (delayed stomach emptying), may be more likely to experience pronounced side effects on Wegovy; the UK SmPC advises caution in people with severe gastrointestinal disease. Those with other digestive conditions, such as irritable bowel syndrome or inflammatory bowel disease, should discuss their history with their prescriber before starting treatment, as the prescriber will need to weigh individual risks.

Those who escalate their dose more quickly than the recommended schedule, or who eat large meals or high-fat foods during the early weeks of treatment, may also find side effects more difficult to manage. Age, sex, and body weight do not reliably predict who will experience side effects, though clinical trial data suggest that gastrointestinal symptoms are among the most common reasons people reduce their dose or discontinue treatment.

Pregnancy and breastfeeding are important considerations. Wegovy is not recommended during pregnancy or breastfeeding. Women of childbearing potential should use effective contraception during treatment. The UK SmPC for Wegovy advises that semaglutide should be discontinued at least two months before a planned pregnancy, given its long half-life.^[1][10] Patients should discuss contraception and family planning with their prescriber before starting or continuing treatment. If you are considering pregnancy, speak to your prescriber well in advance so that any necessary changes to your treatment can be planned.

Note: the advice to use an additional non-oral contraceptive method for four weeks after starting treatment and after each dose increase has been associated with tirzepatide (Mounjaro), not with injectable or oral semaglutide. Patients should follow the contraceptive guidance specific to their prescribed medicine, as confirmed by their prescriber or the relevant SmPC.

People taking other medicines that affect blood glucose, such as insulin or sulfonylureas, may have an increased risk of hypoglycaemia (low blood sugar) when starting Wegovy, as noted in the UK SmPC.^[1][5] Their existing medication may need to be reviewed and doses adjusted by their prescriber. Anyone with a history of pancreatitis should discuss the risks carefully with their doctor before starting treatment, as the UK SmPC advises caution in this group.

Scientific References

1. Wegovy 25 mg tablets – Summary of Product Characteristics.
2. Semaglutide for managing overweight and obesity (TA875).
3. Semaglutide: a medicine to manage type 2 diabetes or weight.
4. Wegovy – European Public Assessment Report.
5. Semaglutide – BNF/NICE.
6. First GLP-1 tablet for weight loss approved in the UK.
7. Wegovy, INN-semaglutide – EPAR product information.
8. Medicines regulator approves up to 7.2 mg dose of semaglutide (Wegovy) for patients with obesity only.
9. GLP-1 receptor agonists: reminder of the potential side effects and to be aware of the potential for misuse.
10. GLP-1 medicines for weight loss and diabetes: what you need to know.
11. Gallstone formation and weight loss – Weinsier RL et al..
12. GLP-1 receptor agonists and dual GLP-1/GIP receptor agonists: strengthened warnings on acute pancreatitis including necrotising and fatal cases.
13. Single-dose 7.2 mg semaglutide (Wegovy) pen approved to treat adult patients with obesity.
14. NG242 Diabetic retinopathy: management and monitoring – effectiveness of intensive treatments to lower blood glucose levels.
15. Semaglutide, reduction in glycated haemoglobin and the risk of diabetic retinopathy – Marso SP et al. Diabetes Obes Metab. 2018.
16. Semaglutide and Cardiovascular Outcomes in Obesity without Diabetes (SELECT) – Lincoff AM et al. NEJM. 2023.

Frequently Asked Questions