Safety Information
Wegovy Tablets Side Effects: What You Need to Know
Quick Answer: Wegovy tablets (oral semaglutide) most commonly cause gastrointestinal side effects — nausea, diarrhoea, constipation and vomiting — especially when starting treatment or increasing the dose. These are usually mild and tend to ease as your body adjusts over days to weeks. Less commonly, more serious effects can occur, including acute pancreatitis and gallbladder problems, which need prompt medical attention. Severe, persistent abdominal pain spreading to the back is a warning sign that requires urgent help.Mostly mildgastrointestinal effects — the most common type
Settleover days to weeks as the body adjusts at each dose
Uncommonserious effects such as pancreatitis — but important to know
Common Side Effects
What Are the Most Common Side Effects?
The most common side effects of Wegovy tablets are gastrointestinal: nausea, diarrhoea, constipation, vomiting, and abdominal discomfort. They are usually mild to moderate in severity and often improve over time as your body adjusts to semaglutide. Other frequently reported effects include indigestion, bloating, burping, headache, tiredness, dizziness, and some hair loss.
The table below separates the common, generally mild effects from the serious ones that need urgent attention.
| Side Effect | Common (mild) | Serious (uncommon) |
|---|---|---|
| Nausea | ✓ | — |
| Diarrhoea | ✓ | — |
| Constipation | ✓ | — |
| Vomiting | ✓ | — |
| Abdominal discomfort / bloating / burping | ✓ | — |
| Indigestion / heartburn | ✓ | — |
| Headache | ✓ | — |
| Tiredness / fatigue | ✓ | — |
| Dizziness | ✓ | — |
| Hair loss | ✓ | — |
| Gallstones (gallbladder disease) | — | ✓ |
| Acute pancreatitis | — | ✓ |
| Low blood sugar (with diabetes medicines) | — | ✓ |
| Serious allergic reaction (anaphylaxis) | — | ✓ |
How long do side effects last? Side effects tend to flare when you first start treatment and after each dose increase, then ease within a week or two as your body adjusts to the new level. If symptoms are severe or do not settle, speak to your pharmacist or prescriber before your next dose increase.
Serious Effects
Serious Concerns to Be Aware Of
While uncommon, the following side effects require prompt medical attention. Knowing the warning signs means you can act quickly if they occur.
| Concern | Signs and Action |
|---|---|
| Acute pancreatitis | Severe, persistent abdominal pain that may spread to the back, sometimes with vomiting. Stop the medicine and seek urgent medical help immediately. |
| Gallbladder disease | Rapid weight loss raises the risk of gallstones. Pain under the right ribs, fever, or yellowing of the skin or eyes should be assessed by a doctor without delay. |
| Low blood sugar (hypoglycaemia) | More likely if semaglutide is combined with insulin or a sulphonylurea for type 2 diabetes. Symptoms: shakiness, sweating, confusion, rapid heartbeat. |
| Dehydration / kidney effects | Persistent vomiting or diarrhoea can cause significant fluid loss. Seek advice if you cannot keep fluids down or notice dizziness and very dark urine. |
| Serious allergic reaction | Rare but potentially life-threatening. Swelling of the face, lips, tongue or throat, or difficulty breathing — call 999 immediately. |
⚠ Stop and seek urgent medical help without delay if you experience:
- Severe, persistent abdominal pain — especially if it spreads to the back
- Persistent vomiting that stops you keeping fluids down
- Signs of dehydration: dizziness, very dark urine, passing little or no urine
- Pain under the right ribs, fever, or yellowing of the skin or eyes
- Swelling of the face, lips, or throat, or difficulty breathing — call 999
Practical Guidance
How to Manage Side Effects
Most gastrointestinal side effects on Wegovy tablets can be significantly reduced with simple measures. The following strategies are recommended alongside following the dose escalation schedule at the pace your prescriber advises.
Self-management guidance
If side effects are affecting your quality of life or preventing you from eating and drinking adequately, do not simply stop the tablet — contact your prescriber or Happy Pharmacy team. They may suggest staying at the current dose for longer, adjusting the escalation pace, or other management strategies before considering whether to stop treatment.
- Build the dose up slowly — do not rush to the next step if current symptoms are troublesome; let your prescriber know
- Eat smaller portions and avoid large, high-fat or greasy meals, which worsen nausea and slow gastric emptying further
- Stay well hydrated — sip fluids steadily through the day rather than drinking large amounts at once
- For nausea: try plain, bland foods (toast, rice, plain crackers) and eat slowly; avoid lying down immediately after eating
- For constipation: increase dietary fibre gradually, drink plenty of water, and stay as active as possible; ask your pharmacist about a gentle laxative if needed
- Take the tablet exactly as directed — on an empty stomach with plain water — to keep its absorption consistent and reduce unpredictable side effects
Eligibility
Who Should Not Take Wegovy Tablets?
Wegovy tablets are not suitable for everyone. It is essential to disclose your full medical history during the prescribing assessment so your clinician can confirm whether this treatment is appropriate for you.
Tell your prescriber about any history of pancreatitis, gallstones, diabetic eye disease (retinopathy) or kidney problems, and provide a full list of all medicines you take — including over-the-counter products and supplements — so they can assess whether Wegovy tablets are right for you and identify any interactions.
| Do Not Take Wegovy Tablets If You Have: | Why |
|---|---|
| Personal or family history of medullary thyroid carcinoma (MTC) or MEN 2 syndrome | Semaglutide is absolutely contraindicated in these conditions due to potential thyroid C-cell risk |
| Had a serious allergic reaction (anaphylaxis) to semaglutide or any tablet ingredient | Re-exposure risks life-threatening reaction |
| Current pregnancy or breastfeeding | Safety not established; not recommended |
Suspected side effects can be reported through the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk or via the Yellow Card app. Your report helps improve medicine safety for everyone.
FAQs
Frequently Asked Questions: Wegovy Tablets Side Effects
Nausea, diarrhoea, constipation, vomiting and abdominal discomfort are the most common. They are usually mild and improve as your body adjusts to the dose. Headache, tiredness, dizziness, indigestion and hair loss are also frequently reported.
Most side effects settle within days to a few weeks. They often return briefly after each dose increase and then ease again as the body re-adjusts. If symptoms are severe or do not settle within two weeks, speak to your prescriber or pharmacist before the next dose increase.
Some people report hair thinning, most commonly related to rapid weight loss and reduced calorie intake rather than semaglutide directly — a condition called telogen effluvium. It usually improves over time. Adequate protein intake and good nutrition help support hair health during treatment.
Yes, constipation is a common side effect, caused partly by semaglutide's slowing of gut transit. Increasing dietary fibre gradually, staying well hydrated, and remaining as active as possible helps. Ask your pharmacist about a gentle laxative if dietary measures are not sufficient.
Stop immediately and seek urgent help for: severe, persistent abdominal pain especially spreading to the back (possible pancreatitis); ongoing vomiting that prevents keeping fluids down; signs of dehydration (dizziness, very dark urine); pain under the right ribs with fever or yellowing skin (possible gallbladder problem); or swelling of the face, lips or throat or difficulty breathing (allergic reaction — call 999).
The side effect profile of oral semaglutide is broadly similar to injectable semaglutide — the same gastrointestinal effects are most common. Because oral tablets are absorbed differently (via the SNAC mechanism), some patients find the GI effects slightly different in character, but the approved 25 mg dose is expected to produce a comparable experience to the 2.4 mg injectable form.
Mild to moderate nausea is expected and does not usually require stopping treatment. Contact your prescriber or Happy Pharmacy team if nausea is severe, prevents you eating or drinking adequately, or does not ease after two weeks. Do not adjust your dose schedule on your own — your clinical team can help find the right approach.
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Wegovy (oral semaglutide) tablets Summary of Product Characteristics. Novo Nordisk. 2025. | MHRA. Yellow Card scheme. yellowcard.mhra.gov.uk | Oral semaglutide 50 mg in adults with overweight or obesity (OASIS 1). Lancet. 2023. | NICE TA875. Semaglutide for managing overweight and obesity. March 2023. | GPhC. Standards for registered pharmacies. 2023. gphc.org.uk | Happy Pharmacy (GPhC No. 9012585). General educational purposes only — not a substitute for personalised medical advice.