Wegovy Side Effects

Semaglutide

This page has been reviewed by
Dr. Nicolette Lammers.

Wegovy is an effective medication for weight reduction, but correct dosing is essential for safety and success. The dose is introduced gradually, starting low and increasing step by step to reduce the risk for side effects.
On this page, you’ll learn:

How to get the correct dose (maybe better: how to get to the correct dose?)
What to do if unwanted effects occur
How to recognize side effects

Being well-informed helps you respond promptly to any issues.

What is Wegovy?

Wegovy is a prescription-only medication for weight reduction containing the active ingredient semaglutide, a GLP-1 receptor agonist. It is intended for adults with:

Obesity (BMI ≥30) or
Overweight (BMI ≥27) with weight-related conditions

Wegovy mimics the natural hormone GLP-1 (glucagon-like peptide-1), which is normally released after meals and one of the (multiple) effects is that it acts on appetite centers in the brain. This increases the feeling of fullness and reduces hunger and cravings, resulting in lower calorie intake and weight loss support.
Administration: Once weekly via a pre-filled injection pen (Wegovy pen).
As with any medication, side effects can occur—commonly gastrointestinal symptoms such as nausea or diarrhea. (Find more details on our main Wegovy page and the subpage on side effects.)

Common Wegovy Side Effects

Like any medication, Wegovy can cause side effects. Many common side effects appear early in treatment or after dose increases and usually lessen over time. They are typically mild and temporary.
However, rare but serious side effects can also occur.
Important: If you are unsure or notice severe/unusual side effects, always consult a doctor.

Frequently Reported (Usually Mild) Side Effects

Nausea: One of the most common effects at the start of therapy; usually subsides after a few days or weeks. (mostly relieved by eating something (we advice 6 small eating moments per day) or not eating too big portions)
Vomiting: Often occurs with nausea; typically decreases over time.(see above)
Diarrhea: Common early in treatment; staying hydrated is important to prevent dehydration.
Constipation: mostly due to increased fluid needs and/or not drinking enough fluids. A High-fiber diet, and physical activity usually help.
Abdominal pain: Often felt as fullness or mild pressure in the upper abdomen; usually improves as the body adjusts. Might also come with diarrhea or it can be a sign of constipation or reflux disease (or worse: gallbladder stones or pancreatitis- so always check with the doctor if symptoms worsen over time).
Headache: Frequently reported early on; usually mild and resolves on its own. Staying hydrated can help. (+ frequent small meals during the day)
Fatigue and weakness: Common during the initiation/weightloss phase; often temporary as the body adapts.
Dizziness: May occur when standing up quickly (linked to blood pressure drop).Common during weightloss, also linked to dehydration.
Digestive discomfort: Includes belching, heartburn, bloating. Typically improves with continued treatment.

Less Common or Serious Side Effects

Pancreatitis (inflammation of the pancreas): Symptoms include severe, persistent abdominal pain (in the upper abdomen, often radiating to the back), often with fever, nausea and vomiting. Stop Wegovy immediately and seek emergency medical care.
Gallstones and gallbladder problems: Rapid weight loss can increase gallstone risk. Symptoms: sudden pain attacks in the upper right abdomen, possibly radiating to back/shoulder, often after fatty meals and often with nausea and vomiting. Seek medical help if severe pain, fever, or yellowing of skin/eyes occurs.
Severe allergic reactions: Signs include breathing difficulties, throat tightness, facial/lip/tongue swelling, rapid heartbeat, or collapse. This is an emergency—call emergency services immediately.
Bowel obstruction (ileus): Extremely rare but serious. Warning signs: severe constipation (no defecation for several days), bloating, severe cramping pain, vomiting. Seek urgent medical care.
Eye problems in diabetics: Rapid blood sugar improvement can temporarily worsen diabetic retinopathy. Symptoms: blurred vision or visual changes. Diabetic patients should have regular eye exams and inform their ophthalmologist about Wegovy use.

How Long Do Wegovy Side Effects Last?

Most side effects occur at the start of treatment or after increasing the dose .
Good news: Common issues like nausea, vomiting, diarrhea, or constipation usually resolve within a few days to weeks as your body adapts. And most side-effects can be prevented by following our intake recommendations. Severity and duration vary individually. Some patients only experience symptoms briefly; others notice them after each dose increase.
Important: Always follow the gradual dose increase prescribed by your doctor to minimize side effects. If severe or persistent symptoms occur, seek medical advice promptly.

What Should I Do If I Experience Side Effects?

Practical strategies to manage or prevent side effects:

Dietary habits: For nausea/vomiting, eat small, low-fat meals, eat slowly, and avoid lying down immediately after eating. Choose bland foods (toast, rice, clear soup).
Hydration: Drink plenty of water; consider oral rehydration solutions if vomiting/diarrhea persists.
Dosage adjustments with your doctor: If side effects worsen after dose increases, you may stay longer on a lower dose before stepping up.
Constipation management: Stay active, eat fiber-rich foods, and drink enough water. If needed, medication may be recommended by your doctor.
Dizziness: Stand up slowly, tense your muscles when standing up; check hydration, eat regularly. Diabetics should monitor glucose more often.
General self-care: Rest if tired, sleep enough, address stress, don’t lose too much weight too fast. Moderate physical activity can boost energy and digestion.
If serious symptoms occur (severe pain, allergic reaction, fainting), seek immediate help and definitely stop Wegovy!

Special Side Effects in Focus

Fatigue and muscle pain: Fatigue is relatively common but temporary. Causes include calorie reduction and body adjustments.
What helps? Adequate rest, hydration, balanced diet with sufficient protein, and gentle exercise.
Muscle pain is rare and usually linked to lifestyle changes (new exercise) or dehydration. Maintain hydration and electrolytes; consult your doctor if persistent.
Constipation: Very common early on; usually improves. Warning: severe, persistent constipation with pain and bloating may indicate obstruction—seek urgent care.
Dizziness: Often linked to low blood pressure, low blood sugar, or dehydration. Eat regular meals and stay hydrated. Patients on medication for hypertension need to check their blood pressure more often; weight loss might decrease their blood pressure and medication might need to be lowered.

Wegovy Treatment at The Body Clinic

The Body Clinic offers individually tailored programs for treatment with Wegovy (active ingredient: semaglutide) when medically indicated.

This means: During the entire medication therapy with semaglutide, you will be under medical supervision. The attending physicians first determine whether medication therapy is medically necessary, identify the appropriate dosage, and monitor the course of treatment. Your progress is regularly reviewed by a doctor with the goal of achieving effective and safe weight reduction.

In addition, we support you with nutritional and exercise recommendations, personal coaching, and, if desired, home delivery of the medication. We provide you with information on how to use the medication, how to manage side effects, and practical tips. If you need more information, you can find the package leaflet here: Wegovy Package Insert.

FAQ

Can Wegovy cause tiredness?

Yes, fatigue is a common side effect, especially during the first few weeks. It typically improves with time.

Can Wegovy cause insomnia?

No, insomnia is not a typical side effect. If you experience sleep problems, check for other factors.

It is a possible side-effect, although not common.. Mostly improved by eating regularly, and a small snack in the evening.

Can Wegovy cause headaches?

Yes, headaches are among the more common side effects. Staying hydrated and managing stress can help.

Can Wegovy cause muscle pain?

Not directly, but indirect causes (exercise, electrolyte changes) may lead to discomfort. Or due to muscle loss during treatment: important to stay active, increase muscle mass and eat enough protein.

How soon does Wegovy work?

The medication starts acting immediately, but noticeable effects (less hunger, weight loss) occur gradually over weeks and months.

Can Wegovy be used during pregnancy or breastfeeding?

No. Wegovy should not be used during pregnancy or breastfeeding. Stop the medication at least two months before planned pregnancy.

Can I drink alcohol on Wegovy?

Occasional/moderate drinking is allowed, but avoid excess. Alcohol adds calories, can cause dehydration, inhibits the reduction of body fat and inhibits building muscle and may increase the risk of pancreatitis.

Summary

Wegovy is highly effective for weight loss when combined with lifestyle changes, but side effects—though usually mild—are common at the start. Most can be relieved by following certain recommendations and/or resolve with time. Close communication with your doctor ensures safe and successful treatment.