Side Effects of Wegovy Injections: What People Commonly Experience

Wegovy (semaglutide) works on GLP-1 receptors involved in appetite regulation and digestion. Because it slows gastric emptying — the rate at which the stomach empties after eating — gastrointestinal effects are the most frequently reported category of side effects. According to the electronic Medicines Compendium (eMC) summary of product characteristics for Wegovy, these include:

• Nausea — the most commonly reported effect, often most noticeable in the first few days after a dose increase
• Vomiting and diarrhoea — reported by a significant proportion of users, particularly early in treatment
• Constipation — a counterpart effect that some people experience alongside or instead of loose stools
• Indigestion, reflux, and burping — linked to slower stomach emptying
• Fatigue and headache — commonly reported, especially during the adjustment period
• Injection-site reactions — redness, mild swelling, or itching at the site of the injection itself

These effects are not universal. Many people find they are mild and temporary, settling within a week or two as their body adapts. Some people experience very little disruption at all, while others find certain dose increases harder to tolerate than others.

If you are also curious about how Wegovy side effects tend to develop over time, or want to understand which Wegovy side effects people find hardest to manage, those pages go into more detail on each area. You may also find it useful to compare notes with the side effects commonly reported with Mounjaro (tirzepatide), which acts on an additional receptor pathway.

When to Contact Your Healthcare Professional

While most side effects are mild and self-limiting, some warrant prompt attention. Contact your prescriber or doctor without delay if you experience severe or persistent abdominal pain (particularly pain that radiates to your back, which can be a sign of pancreatitis), significant or prolonged vomiting, symptoms of an allergic reaction, or anything that feels serious or out of the ordinary. Any side effects that are new, worsening, or concerning should always be discussed with your healthcare professional. Your national reporting scheme (such as the UK's Yellow Card scheme) is also a route to report unexpected reactions — check your country's medicines regulator for the relevant scheme.

One of the most practical things you can do when managing side effects is to log them consistently — so you can spot patterns, understand triggers, and bring accurate information to your prescriber rather than relying on memory.

GLP Trackr's side-effect tracker lets you record how you feel each day — nausea, fatigue, digestive changes, injection-site reactions, and more — so the picture builds up over time rather than being lost between appointments. You might notice, for example, that symptoms peak consistently on the day after your injection and ease by day three, or that they correlate with eating certain foods. That kind of insight is genuinely useful to share with your prescriber.

The app's doctor report feature pulls together your logged side effects, doses, and wellbeing check-ins into a clear summary you can bring to your next appointment — no scrambling to remember what happened six weeks ago.

For a broader view of managing your experience on GLP-1 medications, the complete guide to GLP-1 side effects covers the topic in depth and links out to related pages.

GLP Trackr is an information and tracking tool — it is not a substitute for your prescriber's guidance. If your side effects are severe, persistent, or worrying, contact your healthcare professional promptly. Any decisions about your dose or treatment belong with your prescriber, who knows your full history.

Ready to start logging? GLP Trackr is free to try for 7 days — download it on the App Store or Google Play and give your journey the structure it deserves.