Weight Loss
Wegovy Pill Side Effects and How to Manage Them
In one sentence
The most common Wegovy pill side effects are digestive, such as nausea, diarrhoea and constipation; they are usually mild, tend to ease as your body adjusts, and can be managed with a few simple changes.
At a glance
The most common side effects are gastrointestinal: nausea, diarrhoea, constipation, indigestion and vomiting.
They are usually mild to moderate and tend to settle as your body adjusts, especially after the first few weeks.
Building the dose up slowly (titration) is designed to reduce them.
Simple steps help: smaller, plainer meals, staying hydrated and getting enough fibre.
Serious side effects are rare. Seek urgent help for severe, lasting stomach pain.
Tell your prescriber about any diabetes medicines, as your doses may need adjusting.
Like all effective medicines, the Wegovy pill can cause side effects. The good news is that most are digestive, mild and temporary, and there is a lot you can do to ease them. This guide explains what to expect, how to manage the common ones, and the rare warning signs that mean you should seek help.
Key takeaways
What are the most common side effects? Digestive ones, mainly nausea, diarrhoea, constipation, indigestion and vomiting.
Are they serious? Usually not. Most are mild to moderate and settle over the first few weeks.
How do you reduce them? Smaller, plainer meals, staying hydrated, enough fibre, and building the dose up slowly.
When should you seek help? For severe or lasting stomach pain, signs of dehydration, or an allergic reaction.
What are the side effects of the Wegovy pill?
The most common Wegovy pill side effects affect the stomach and gut, because the medicine slows digestion. The approved product information groups the possible effects by how often they happen.1 The table below summarises them.
How often | Possible side effects |
Very common (more than 1 in 10) | Nausea, diarrhoea, constipation, indigestion, vomiting, stomach pain, headache, tiredness |
Common (up to 1 in 10) | Acid reflux, burping, bloating, wind, dizziness, changes in taste, hair loss, gallstones, low blood sugar (mainly in people with type 2 diabetes) |
Uncommon or rare | Inflammation of the pancreas (pancreatitis), a faster heart rate, dehydration and kidney effects, kidney stones, serious allergic reactions |
Inflammation of the pancreas (pancreatitis), a faster heart rate, dehydration and kidney effects, kidney stones, serious allergic reactions
How common are Wegovy pill side effects, and how long do they last?
Digestive side effects are very common, but for most people they are mild and short-lived. They tend to be at their strongest in the first week or two and for a short time after each dose increase, then ease as your body gets used to the medicine. This is exactly why the dose is built up gradually. See the Wegovy pill dosage and titration schedule.
"Most side effects from the Wegovy pill are simply your body getting used to the medicine, not a sign that something is wrong. They are usually at their worst in the first week or two, and just after a dose increase, then they settle. Building the dose up slowly is what keeps them manageable."
How to manage nausea on the Wegovy pill
Nausea is the most common side effect, and small changes usually help a great deal:
Eat smaller meals more often, and stop as soon as you feel full.
Choose plain, bland foods such as toast, rice and crackers when you feel queasy.
Avoid greasy, fried and very rich foods, which tend to make it worse.
Do not lie down straight after eating, and get some fresh air.
Sip water and try ginger tea, which some people find soothing.
Our guide to what to eat on the Wegovy pill has more detail.
"For nausea, small and plain beats large and rich every time. Eat little and often, stop the moment you feel full, and go easy on greasy foods. For most people it fades within a few weeks as the body adjusts."
How to manage diarrhoea and constipation
The Wegovy pill can cause either loose stools or constipation. For diarrhoea, drink plenty of fluids to stay hydrated and eat simple foods until it settles. For constipation, which is common because the medicine slows digestion, eat more fibre such as wholegrains, vegetables, fruit and pulses, drink enough water and keep active. If either is severe or does not settle, speak to your pharmacist or prescriber.
Does the Wegovy pill cause hair loss?
Some hair thinning is listed as a possible side effect. Where it happens, it is often linked to rapid weight loss itself rather than the medicine directly, and it is usually temporary, improving as your weight stabilises. Eating enough protein supports healthy hair. If hair loss is significant or worrying, speak to your prescriber.
Serious side effects and when to get help
Serious side effects are uncommon to rare, but it is important to know the warning signs so you can act quickly.1
Get urgent medical help if you have:
Severe, lasting stomach pain, especially if it spreads to your back and comes with vomiting. This can be a sign of pancreatitis.
Pain in the upper right stomach, yellowing of the skin or eyes, or fever, which can point to a gallbladder problem.
Signs of dehydration from vomiting or diarrhoea, such as passing very little or very dark urine, or feeling dizzy.
Signs of a serious allergic reaction, such as swelling of the face, lips or throat, or trouble breathing. Call 999.
If you take insulin or a sulfonylurea for type 2 diabetes, be aware of low blood sugar (shakiness, sweating, confusion), as these medicines together can increase the risk.2 For a fuller explanation of the rarer risks, see our guide to Wegovy pill safety warnings.
"There are a few symptoms I never want people to sit on. Severe stomach pain that spreads to your back, especially with vomiting, needs urgent attention, as do the signs of a serious allergic reaction. These are rare, but knowing them means you can act quickly. If in doubt, always get it checked."
Can Wegovy pill side effects be reduced?
Yes. The slow dose build-up, sensible eating and good hydration all make a real difference, and most side effects ease with time. If they are hard to manage, do not simply stop or push through. Your prescriber can hold your dose at the current level rather than increasing it, which often helps. To find out if the Wegovy pill is right for you, our clinicians can assess your suitability through an online weight-loss consultation.
Related Wegovy pill guides
Frequently asked questions about Wegovy pill side effects
What are the most common side effects of the Wegovy pill?
The most common side effects are digestive: nausea, diarrhoea, constipation, indigestion and vomiting. Headache and tiredness are also very common. Most are mild to moderate and tend to settle as your body adjusts.
How long do Wegovy pill side effects last?
For most people, they are strongest in the first week or two and for a short time after each dose increase, then ease over the following weeks. Building the dose up slowly is designed to keep them manageable.
Does the Wegovy pill cause constipation?
Yes, constipation is common because the medicine slows digestion. Eating more fibre, drinking enough water and staying active usually helps. If it is severe or does not settle, speak to your pharmacist or prescriber.
How do you stop feeling sick on the Wegovy pill?
Eat smaller, plainer meals, stop as soon as you feel full, and avoid greasy or very rich foods. Do not lie down straight after eating, sip water, and try ginger. Nausea usually fades within a few weeks.
Does the Wegovy pill cause hair loss?
Some hair thinning is possible. It is often linked to rapid weight loss itself rather than the medicine, and is usually temporary, improving as your weight stabilises. Eating enough protein can help. Speak to your prescriber if it is significant.
When should you see a doctor about Wegovy pill side effects?
Get urgent help for severe or lasting stomach pain, especially if it spreads to your back with vomiting, for signs of dehydration, or for a serious allergic reaction such as swelling or trouble breathing. Call 999 for a severe allergic reaction.
Sources and references
electronic medicines compendium (emc). Wegovy tablets: Summary of Product Characteristics. Section 4.8 lists nausea, diarrhoea, constipation, indigestion, vomiting, abdominal pain, headache and fatigue as very common, and pancreatitis, dehydration-related and allergic reactions among the uncommon to rare effects.
Diabetes UK. Wegovy (semaglutide). Notes that low blood sugar is more likely when semaglutide is taken with other diabetes medicines such as insulin or a sulfonylurea.
Medical disclaimer: This article is for general information and does not replace advice from a qualified healthcare professional. Always read the patient information leaflet for the full list of side effects. If you feel unwell or are worried about a symptom, contact your prescriber, pharmacist or GP, or call NHS 111. Call 999 in an emergency.
Our commitment to accuracy: This page reflects the approved product information and current UK guidance from sources such as the emc, NHS, NICE and the MHRA. It is reviewed by our Superintendent Pharmacist and updated as guidance changes.
About the author
Blog author
Dayna Sheppard
Dayna is a pharmacy manager with over 15 years of pharmacy experience. She is focused on delivering a safe and excellent pharmacy service for patients.
Medically reviewed by
Medical reviewer
Taslima Hussain
Taslima is a pharmacist who is passionate about patient care. She has experience working in community pharmacy as a locum.
