Safety Information
Wegovy Tablets Side Effects: What You Need to Know
Quick Answer: Wegovy tablets (oral semaglutide) most commonly cause gastrointestinal side effects such as 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. Less commonly, more serious effects can occur — including acute pancreatitis and gallbladder disease — which need prompt medical attention.Mostly mildgastrointestinal effects that ease as your body adjusts
Days–weeksfor most side effects to settle at each dose step
Uncommonserious effects such as pancreatitis — but important to know
Overview
Common Side Effects at a Glance
The most common side effects are gastrointestinal: nausea, diarrhoea, constipation, vomiting and abdominal discomfort. They are usually mild to moderate and often improve over time. They tend to flare when you first start and after each dose increase, then ease within a week or two as your body adjusts. Other frequently reported effects include indigestion, bloating, burping, headache, tiredness and dizziness.
| Side Effect | Common (mild) | Serious (seek help) |
|---|---|---|
| Nausea | ✓ | — |
| Diarrhoea | ✓ | — |
| Constipation | ✓ | — |
| Vomiting | ✓ | — |
| Abdominal pain / indigestion | ✓ | — |
| Headache, tiredness, dizziness | ✓ | — |
| Hair loss | ✓ (usually temporary) | — |
| Acute pancreatitis | — | ✓ — seek urgent help |
| Gallbladder disease (gallstones) | — | ✓ — seek urgent help |
| Low blood sugar (with diabetes medicines) | — | ✓ — monitor and seek help |
| Severe allergic reaction | — | ✓ — call 999 |
How long do side effects last? Side effects tend to flare when you start and after each dose increase, then ease within a week or two as your body adjusts. If symptoms are severe or do not settle, speak to your pharmacist or prescriber before your next dose increase.
Serious Concerns
Side Effects That Need Prompt Medical Attention
| 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 checked promptly by a clinician. |
| Low blood sugar | More likely if combined with insulin or a sulphonylurea for type 2 diabetes. Symptoms include shakiness, sweating, confusion and rapid heartbeat. |
| Dehydration / kidney | Persistent vomiting or diarrhoea can cause significant fluid loss. Seek advice if you cannot keep fluids down. |
| Severe allergic reaction | Rare but serious. Call 999 for swelling of the face, lips or throat, or difficulty breathing. Do not take further doses without clinical review. |
⚠ Contact your GP or seek urgent help without delay if you experience:
- Severe, persistent abdominal pain — especially spreading to the back
- Persistent vomiting that stops you keeping fluids down
- Signs of dehydration: dizziness, dark urine, passing little 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
Managing Side Effects
How to Manage Common Side Effects
Who Should Not Take Wegovy Tablets?
Wegovy tablets are not suitable for everyone. The treatment should not be used by people with a personal or family history of medullary thyroid carcinoma (MTC) or MEN 2 syndrome, anyone who has had a serious allergic reaction to semaglutide, or during pregnancy or breastfeeding. Tell your prescriber about any history of pancreatitis, gallstones, diabetic eye disease or kidney problems, and about all other medicines you take, so they can judge whether Wegovy tablets are right for you.
🍽️ Nausea & Vomiting
Eat smaller portions and avoid large, high-fat or greasy meals. Choose plain, easily digestible foods during flare-ups. Eat slowly and sip fluids throughout the day. Do not rush to the next dose step if symptoms are troublesome — tell your prescriber.
💧 Constipation
Increase fibre intake — vegetables, fruit, wholegrains and legumes. Stay well hydrated throughout the day. Keep active. Ask your pharmacist about a gentle, over-the-counter remedy if needed.
🚿 Diarrhoea & Dehydration
Sip fluids regularly — water, diluted juice or an oral rehydration solution. Avoid caffeine and alcohol. If you cannot keep fluids down or symptoms last more than 48 hours, seek medical advice.
💊 Dose Escalation
Build the dose up slowly and do not rush to the next step if symptoms are troublesome. Your prescriber may keep you at the current dose for longer. Take the tablet exactly as directed — on an empty stomach — to keep its effect consistent.
Reporting side effects: Suspected side effects can be reported to 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 Tablet Side Effects
Nausea, diarrhoea, constipation, vomiting and abdominal discomfort are the most common. They are usually mild and improve as your body adjusts to each dose. Other frequently reported effects include indigestion, bloating, headache, tiredness and dizziness.
Most settle within days to a couple of weeks. They often return briefly after each dose increase and then ease again as your body adjusts to the new level. If symptoms are severe or do not settle within two weeks of a dose increase, speak to your pharmacist or prescriber.
Some people report hair thinning, which is often linked to rapid weight loss rather than the medicine itself — a temporary phenomenon called telogen effluvium. It usually improves over time. Eating adequate protein throughout treatment can help minimise this.
Yes, constipation is a common side effect. Increasing dietary fibre and fluid intake, staying physically active, and asking your pharmacist about a gentle remedy can all help. Semaglutide slows the rate at which food passes through the digestive system, which is the underlying cause.
The most important serious side effects are acute pancreatitis (severe, persistent abdominal pain radiating to the back) and gallbladder disease (pain under the right ribs, fever or yellowing of the skin). Stop the medicine and seek urgent medical help if you experience these. A severe allergic reaction — facial swelling, throat swelling or difficulty breathing — requires calling 999 immediately.
Stop and seek urgent help for severe, persistent abdominal pain spreading to the back, ongoing vomiting preventing fluid intake, signs of dehydration (dizziness, dark urine), pain under the right ribs with fever or jaundice, or any allergic reaction such as facial swelling or breathing difficulty. For concerns that are not urgent, contact your Happy Pharmacy team.
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Wegovy (semaglutide) Summary of Product Characteristics. Novo Nordisk. 2025. MHRA Yellow Card scheme: yellowcard.mhra.gov.uk. NICE TA875. 2023. Happy Pharmacy (GPhC No. 9012585). General educational purposes only — not a substitute for personalised medical advice.