Wegovy pill side effects: what to expect and when to get help

DoktorABC editorial team

Accurate, up-to-date health information written by our editorial team and reviewed by UK-registered prescribers.

Why can the Wegovy pill cause side effects?

Semaglutide slows the rate at which your stomach empties and influences your appetite, which helps explain why digestive symptoms are the ones people report most often. Your prescriber increases the dose in steps, so it's common for symptoms to feel more noticeable around those points while your body gets used to the medicine.

What are the side effects of the Wegovy pill?

The SmPC and PIL group side effects according to how often they occur in the people studied. An effect described as very common affected more than 1 in 10 people, while a rarer one affected far fewer. Even so, a low frequency isn't a promise that an effect won't happen to you.

Nausea, vomiting and diarrhoea can also cause you to lose fluids, which is why the PIL stresses the importance of drinking enough.

How can you manage Wegovy pill side effects?

A few simple habits may take the edge off everyday symptoms. They're low risk for most people, but they don't replace advice from your prescriber.

• Eat smaller meals. Large portions may make nausea, reflux and bloating feel worse.
• Notice your trigger foods. If rich, greasy or very spicy dishes tend to upset your stomach, you may find it helps to have less of them.
• Sip fluids regularly. This matters most if you're being sick or have diarrhoea.
• Take the tablet as directed. The SmPC says to swallow it whole with a sip of water on an empty stomach, then wait 30 minutes before you eat, drink or take other medicines.
• Check before taking anything else. A pharmacist or your prescriber can advise whether a medicine for sickness or diarrhoea is suitable alongside your treatment.
• Speak to your prescriber before changing your dose. It's best not to stop, skip or adjust it yourself.

When should you contact a clinician?

It's worth speaking to your prescriber, GP or pharmacist if you notice any of the following:

• Repeated vomiting
• Difficulty keeping fluids down
• Signs of dehydration, such as very dark urine, a dry mouth, extreme thirst or feeling dizzy
• Symptoms that are severe or don't ease
• Concerns about low blood sugar, particularly if you use insulin or a sulfonylurea, as the PIL notes that the risk may be higher in that case

If you take medicines for diabetes, don't adjust them yourself, as your clinician may need to review them.

Which side effects need urgent help?

• Severe, persistent abdominal pain, with or without nausea and vomiting. This may be a sign of pancreatitis and can spread to your back. The PIL advises stopping the medicine and seeking urgent medical help, and the MHRA strengthened its warning on pancreatitis with GLP-1 medicines in January 2026.
• A serious allergic reaction. Swelling of the face, lips, tongue or throat, or difficulty breathing, needs a 999 call.
• Sudden vision loss or rapidly worsening eyesight. The SmPC advises urgent eye assessment for any sudden loss of vision, and if you have diabetes, it's important to tell your prescriber about changes to your eyesight.
• Possible gallbladder problems. Gallstones are a common side effect, and the NHS describes pain in the middle of your tummy or under your right ribs that lasts longer than 30 minutes. A high temperature, chills or yellowing of the skin or whites of the eyes need urgent care.

What about Wegovy pill side effects in females?

The frequency table in the product information isn't divided by sex, so the side effects above apply to anyone taking the medicine. Where the guidance does differ is around pregnancy and contraception:

• Wegovy shouldn't be used during pregnancy or breastfeeding.
• The SmPC advises stopping semaglutide at least 2 months before a planned pregnancy.
• Women who could become pregnant are advised to use contraception while they're being treated.
• In interaction studies, the SmPC reports no clinically relevant change in exposure to oral contraceptives containing ethinylestradiol and levonorgestrel.

Advice on contraception is specific to each medicine, so guidance you've seen for other weight loss medicines doesn't automatically apply to semaglutide. If you're pregnant, planning a pregnancy or breastfeeding, tell your prescriber, who can also talk you through which contraception suits you.

Surgery and reporting side effects

If you're due to have an operation, please tell your surgical and anaesthetic team that you take Wegovy. In January 2025 the MHRA warned that GLP-1 medicines are linked to a risk of stomach contents entering the lungs during general anaesthesia or deep sedation, so it's worth mentioning even if your prescription was private.

If you suspect a side effect, you can report it through the MHRA Yellow Card scheme at yellowcard.mhra.gov.uk. Patients can submit reports as well as healthcare professionals.

Final thoughts

Wegovy pill side effects are mainly gastrointestinal, with nausea, vomiting, diarrhoea, constipation, indigestion, abdominal pain, headache and fatigue all listed as very common. Smaller meals, regular fluids and taking the tablet as directed may help, but symptoms that are severe or that don't ease deserve advice rather than a long wait. Serious effects are much rarer, though they do need urgent help when they occur. DoktorABC connects UK patients with UK-registered prescribers who can review your symptoms and your treatment.

FAQ

The DoktorABC medical advisory board

Dr. Roland Ruiken

Medical advisor, Norway

Dr. Viktor Simunovic

Medical advisor, Croatia

To the medical advisory board