Wegovy Side Effects | What to Expect UK Guide

If you are starting Wegovy, it is common to have questions about side effects. This guide explains the most common symptoms, when they happen, and how they usually improve over time.

What You’ll Learn

The most common Wegovy side effects
When side effects usually occur
How long they tend to last
What is considered normal
When to seek advice

Common Wegovy Side Effects

Like other weight loss injections, Wegovy can cause side effects, especially during the early stages of treatment.

Nausea
Reduced appetite
Vomiting or diarrhoea
Constipation
Fatigue

These symptoms are usually mild and improve as your body adjusts.

When Do Side Effects Start?

Side effects are most likely to occur:

When you first begin Wegovy
After increasing your dose

This is part of how the body responds to the medication.

How Long Do Side Effects Last?

For most people, side effects improve over time.

Early weeks: Symptoms may be more noticeable
After adjustment: Symptoms often reduce
Long-term: Many people experience minimal side effects

Are Side Effects Worse at Higher Doses?

Side effects can become more noticeable as doses increase, particularly during escalation.

This is why Wegovy follows a gradual dose schedule.

See the Wegovy Dosing Guide for more detail.

When Should You Be Concerned?

Most side effects are mild, but you should seek advice if:

Symptoms are severe or persistent
You are unable to keep fluids down
You experience unusual or worsening symptoms

For more detail, see Serious Side Effects.

How to Reduce Side Effects

Simple changes can help manage symptoms:

Eat smaller, lighter meals
Avoid rich or fatty foods
Stay hydrated
Follow your dosing schedule carefully

See How to Reduce Side Effects for more practical tips.

Are Side Effects a Sign It’s Working?

Not necessarily.

Some people experience side effects, while others do not. Wegovy can still be effective without noticeable symptoms.

Not Sure What to Expect?

Starting treatment? Read How Wegovy Works
Understanding doses? See Wegovy Dosing Guide
Comparing options? Read Mounjaro vs Wegovy