Wegovy drug interactions: 12 medications that affect semaglutide
Which medicines interact with Wegovy? Learn about 12 key drug interactions that might affect your treatment.
Before taking Wegovy (semaglutide), it's important to let your prescriber know about any drugs you're already taking.
That's because some drugs can affect how other drugs work. When this happens, we call it an 'interaction'.
This isn't something you usually have to worry about. As long as your prescriber knows which medications you're using, they can tailor your treatment to keep it safe and effective. This might mean:
- Stopping the drug you're already using
- Changing the dose or other aspects of the treatment
- Continuing with your current treatment and not starting Wegovy
However, the more you know about drug interactions, the more you can do to keep yourself safe and healthy. That's why we've put together this guide to Wegovy drug interactions. We hope it helps you feel confident as you start your weight loss journey.
A quick note for Ozempic users: Ozempic and Wegovy both contain semaglutide, but they're licensed for different uses and doses. Many semaglutide interactions apply to both drugs, but you should always check the leaflet for the product you're actually using.
The list: 10 medication groups that may interact with Wegovy
Drugs where extra care is needed
1. Insulin and sulfonylureas
Insulin is a hormone that helps move sugar from your blood into your cells for energy. Some people with type 2 diabetes inject insulin to manage their blood sugar. Sulfonylureas, such as gliclazide and glimepiride, are tablets that make your pancreas release more insulin.
Wegovy can make low blood sugar more likely if you also use insulin or a sulfonylurea. If you take one of these drugs, your doctor may lower your dose when starting Wegovy. They may also ask you to check your blood glucose more often.
At SemaPen, we take patient safety very seriously. That's why we do not allow patients taking insulin or sulfonylureas to join the SemaPen programme.
2. Other GLP-1 receptor agonists
Wegovy is part of a group of medicines called 'GLP-1 receptor agonists'. All these drugs work in a similar way. They help lower blood sugar and support weight loss by mimicking a natural hormone that controls appetite and digestion.
Examples of GLP-1 receptor agonists and related medications include:
- Wegovy (semaglutide)
- Mounjaro (tirzepatide)
- Saxenda (liraglutide)
- Ozempic (semaglutide) – used to treat type 2 diabetes
- Trulicity (dulaglutide) – used to treat type 2 diabetes
Do not use Wegovy together with another GLP-1 receptor agonist. This combination is likely to increase the risk of side effects.
3. DPP4 inhibitors
DPP4 inhibitors are another type of diabetes drug. These work by preventing the breakdown of GLP-1 – the same hormone that Wegovy and similar drugs mimic to stimulate weight loss.
For this reason, it's not recommended to take Wegovy alongside a DPP4 inhibitor. If you're already using a DPP4 inhibitor, ask your doctor to prescribe a safe alternative such as metformin.
Most DPP4 inhibitors have names that end with 'gliptin'. Examples include:
- Januvia (sitagliptin)
- Trajenta (linagliptin)
- Vipidia (alogliptin)
- Galvus (vildagliptin)
Other treatments that may interact with Wegovy
4. Other weight-loss treatments
These include prescription treatments, pharmacy products you can buy without a prescription and herbal supplements that claim to curb appetite or burn fat.
It's not recommended to take Wegovy alongside another weight loss treatment. That's because the combination likely hasn't been studied, so we don't know what the effects might be.
If you're already taking one, speak to your prescriber about switching rather than combining. Remember to tell them about any treatments you use, including supplements and herbal medications.
5. Combined oral contraceptives
Also known as 'the pill', these medications include a combination of hormones that help prevent unwanted pregnancy in women and people assigned female at birth.
Studies show Wegovy does not reduce the effectiveness of the pill. However, certain
Wegovy side effects, such as nausea and vomiting, may impact the way the pill works.
If you vomit soon after taking a pill or have ongoing vomiting or severe diarrhoea, follow NHS advice.
6. Warfarin and other coumarins
Warfarin (and similar medicines called 'coumarins') are blood thinners used to prevent blood clots. Doses are guided by your INR blood test, which checks how quickly your blood clots.
Wegovy didn't change warfarin levels in studies. However, the manufacturer's leaflet advises extra INR checks when you start or change your Wegovy dose. Your clinic will tell you how often to test. Always seek medical advice if you notice unusual bruising or bleeding.
7. Paracetamol (acetaminophen)
Paracetamol is a common pain and fever reliever you can buy without a prescription.
Wegovy may slow how quickly paracetamol starts to work, but your body still absorbs the full amount. You don't need to change your usual dose.
8. Atorvastatin
Atorvastatin is a statin medicine used to lower cholesterol and protect heart health.
You don't usually have to change dosage when using Wegovy. A study found that peak levels were slightly lower, but the overall effect of the drug stayed the same.
9. Metformin
Metformin is a common tablet for type 2 diabetes that helps lower blood sugar.
Studies haven't shown any clinically meaningful interaction with Wegovy. You probably won't need a dose change. Keep taking it as prescribed and be sure to let your clinician know about all the medications you're taking.
10. Drugs that need fast absorption
These are medicines designed to work quickly (for example, some rapid-acting pain or migraine treatments).
Because Wegovy can slow stomach emptying, these medicines may take longer to start working. When you start Wegovy, your prescriber may suggest:
- Taking the drugs at specific times
- A different formulation
- Extra monitoring
A note on other medications
Researchers haven't tested Wegovy alongside every drug. That's why it's really important to tell your prescriber about all your prescriptions and any supplements you use. That's so they can check for possible interactions and help keep you safe.
What about operations under general anaesthesia?
GLP-1 medicines like Wegovy can slow stomach emptying, meaning food may stay in the stomach longer. That can increase the risk of aspiration (food entering the lungs) during anaesthesia.
If you're having an operation under heavy sedation or general anaesthesia, always let your surgical or endoscopy team know that you're taking semaglutide. This way, they can give you the right fasting advice and make sure the procedure is safe.
Practical tips for patients
- Always share your full medicines list (including over-the-counter and herbal products) with your GP or healthcare provider.
- Take extra care if you use diabetes drugs or another GLP-1 medication. Your prescriber may need to change your dose or stop treatment.
- If you take warfarin or another coumarin, expect extra INR checks when Wegovy is started or adjusted.
- Before procedures with anaesthesia or deep sedation, always tell the team you're taking semaglutide.
- Know sick-day rules: if vomiting or diarrhoea persist and you can't keep fluids down, contact your care team.
How SemaPen supports you
With SemaPen, you're never left to figure things out on your own. Our Wegovy and Mounjaro weight loss programmes begin with a full clinical assessment. We'll ask about the medications you're taking and make sure any Wegovy drug interactions are accounted for.
And that's just the start. If you're approved for treatment, you'll also get a host of extras to help on your weight loss journey:
- Around-the-clock support from a team of real obesity experts.
- A digital smart scale that tracks your progress in the cloud.
- Check-ins and tips from our team to keep you on track.
- Access to exclusive recipes and guides through the SemaPen app.
- A money-back guarantee if treatment doesn't work for you.*
Ready to take the next step to better health? It all starts with our simple
online consultation. We'll review your answers right away and let you know the best course of treatment for you.
Sources and small print
European Medicines Agency (2025) European Public Assessment Report (EPAR) for Wegovy. Retrieved from https://www.ema.europa.eu/en/documents/product-information/wegovy-epar-product-information_en.pdf
Novo Nordisk (2024) Package leaflet: Information for the patient [leaflet]. Retrieved from https://www.medicines.org.uk/emc/files/pil.13800.pdf
*
Terms and conditions apply.
This article was reviewed and approved by Alice Fletcher, Lead Bariatric Dietitian, on 3 September 2025.
