If you are asking about Wegovy needles, the key point is that the current UK Wegovy FlexTouch pen uses a separate disposable needle. It is not a built in needle system. Mounjaro KwikPen also uses a separate disposable needle, but compatible needles are not included with the Mounjaro pen pack.
For UK adults aged 18 and over who are prescribed Wegovy or Mounjaro, this difference affects what supplies you need, how you prepare the pen, and how you dispose of the used needle. Both medicines are prescription only treatments, so your healthcare professional can explain how to use the specific pen prescribed for you.
Below, we compare the Wegovy and Mounjaro pen and needle systems, explain how each pen works in practice, and cover the day to day points that matter when using either treatment, including handling, storage, disposal, side effects, suitability and effectiveness.
Key things to know
- Mounjaro KwikPen does not include needles in the pack. You need a compatible disposable pen needle for each injection
- UK Wegovy FlexTouch pens are supplied with 4 disposable NovoFine Plus needles, and the pen can also be used with compatible NovoFine or NovoTwist needles up to 8mm long
- Both pens are multi dose devices, with 4 doses in each pen
- A fresh disposable needle should be used for each injection and removed after use
- The exact instructions can differ between products, so always follow the patient information leaflet and instructions supplied with your prescribed pen
The Mounjaro KwikPen: Needle Attached Separately
Mounjaro KwikPen is a multi dose device containing 4 doses. The pen pack does not include the needles. Before each injection, a compatible disposable pen needle needs to be attached to the pen. The needle is then removed and disposed of after the injection.
The manufacturer provides instructions on which type of compatible pen needle to use. If you are unsure which needle is suitable, ask your prescriber or pharmacist rather than choosing one based only on its appearance or size.
A new needle should be used for each injection. The used needle should be removed from the pen and disposed of safely after use.
The Wegovy FlexTouch Pen: Needle Also Attached Separately
The current UK Wegovy FlexTouch pen also uses a separate disposable needle. Each pen contains 4 doses and the pack contains 4 NovoFine Plus needles. The pen is also designed to work with NovoFine and NovoTwist disposable needles up to 8mm long.
Before each injection, a new needle is attached to the Wegovy pen. After the injection, the needle should be removed and disposed of. The pen should be stored without a needle attached.
This means the original comparison between a concealed built in Wegovy needle and a separately attached Mounjaro needle is not accurate for the current UK Wegovy FlexTouch format.
If you are comparing Wegovy and Mounjaro in the UK, the more useful difference is that Wegovy FlexTouch is supplied with 4 NovoFine Plus needles, while Mounjaro KwikPen does not include needles in the pack.
Side by Side: How the Two Pen and Needle Systems Compare
| Mounjaro KwikPen | Wegovy FlexTouch pen | |
|---|---|---|
| Needle included in pack? | No, needles are supplied separately | Yes, 4 NovoFine Plus needles are supplied |
| Doses per pen | 4 doses | 4 doses |
| Needle used | Separate disposable pen needle | Separate disposable pen needle |
| Needle removed after injection? | Yes | Yes |
| Needle options | Use a compatible pen needle | NovoFine Plus, NovoFine or NovoTwist up to 8mm |
| Pen type | Multi dose | Multi dose |
Neither system is necessarily better for everyone. With Wegovy, the starter pack includes the needles needed for the 4 doses. With Mounjaro, you need to make sure you have compatible needles available before using the pen.
The most important point is to follow the instructions for your specific medicine and pen rather than assuming that the two systems work in exactly the same way.
Why This Distinction Matters Practically
If you are prescribed Mounjaro, you need to arrange a supply of compatible needles because these are not included in the pen pack. This is something worth checking before your first injection so that you have everything you need.
If you are prescribed Wegovy FlexTouch, the pack contains 4 NovoFine Plus needles for the 4 doses in the pen. You can also use compatible NovoFine or NovoTwist needles up to 8mm, as specified in the product information.
Getting the supplies right can make it easier to follow the instructions for your treatment. Do not attach a needle that you are unsure is compatible with your pen. If you have questions about the correct needle, speak with your pharmacist or prescriber.
Beyond Needles: What Actually Differs Between the Weight Loss Medicines
Since the pen system is only one part of the comparison, it is also useful to understand how the medicines themselves differ.
Mounjaro contains tirzepatide, which acts on GIP and GLP 1 receptors. Wegovy contains semaglutide, which acts on the GLP 1 receptor. These are different medicines, so they are not simply different brands of the same treatment.
Semaglutide is also the active ingredient in Ozempic. However, Ozempic and Wegovy have different licensed uses and strengths, so they should not be treated as interchangeable medicines.
Your medical history, current medicines, health conditions and treatment goals all need to be considered when deciding whether Wegovy or Mounjaro is suitable for you.
Clinical studies have reported weight loss with both medicines, but individual results vary. In SURMOUNT 1, average weight loss at 72 weeks was 15.0% with 5mg tirzepatide, 19.5% with 10mg and 20.9% with 15mg. In STEP 1, participants taking semaglutide 2.4mg had an average weight loss of around 15% at 68 weeks.
These are results from specific clinical studies and should not be treated as a prediction of how much weight you will lose.
Which Is More Effective? What the Evidence Actually Says
The SURMOUNT 5 trial directly compared tirzepatide with semaglutide. The study reported greater average weight loss with tirzepatide than with semaglutide over the study period.
The reported average weight loss was 20.2% with tirzepatide and 13.7% with semaglutide. These figures describe the study groups and do not mean that everyone taking Mounjaro will lose more weight than everyone taking Wegovy.
Effectiveness is also not the only factor to consider. Side effects, how you respond to treatment, your medical history, your preferences and how the pen fits into your routine can all be relevant.
Your prescriber can help you consider the available evidence alongside your individual circumstances.
Disposing of Used Pens and Needles Safely
Used needles should not be placed in household waste. They should be disposed of in an appropriate sharps container, following local guidance.
With Mounjaro, remove the needle after each injection and place it in your sharps container. The empty pen should also be disposed of according to the instructions provided with your medicine.
With Wegovy FlexTouch, remove the needle after each injection and dispose of it safely. The pen itself should be disposed of after all 4 doses have been used, following the product instructions.
Your local pharmacy or council may be able to advise you about sharps disposal services available in your area.
Storage: What Is Similar Between the Two
Both Mounjaro and Wegovy have specific storage requirements. Follow the storage instructions supplied with your medicine rather than assuming that both products have exactly the same storage period outside the fridge.
Wegovy FlexTouch should be stored according to the instructions in its patient information leaflet. The same applies to Mounjaro KwikPen.
Before using either pen, check the product information and make sure the medicine has been stored correctly. If you are unsure whether your pen has been exposed to temperatures outside the recommended range, speak with your pharmacist before using it.
Both medicines are injected under the skin. Follow the instructions supplied with your specific pen for the recommended injection sites and technique.
Side Effects: Some Similarities Between the Two
Both Wegovy and Mounjaro can cause gastrointestinal side effects such as nausea, diarrhoea and constipation. Headache can also occur. Side effects can be more noticeable for some people when treatment is started or when the dose is increased.
The side effects are related to the medicine rather than whether the pen uses a separate needle.
If you experience side effects that concern you or make it difficult to continue with treatment, speak with your prescriber or pharmacist. Severe or persistent symptoms should be assessed by a healthcare professional.
Seek urgent medical attention if you develop severe abdominal pain, particularly if it does not go away or is accompanied by other concerning symptoms.
Who Each Medicine Is Suitable For
Both Mounjaro and Wegovy may be prescribed for weight management in eligible adults who meet the relevant clinical criteria. Eligibility can depend on factors such as BMI, weight related health conditions, medical history and other medicines you take.
Neither medicine should be used during pregnancy. If you are pregnant, planning to become pregnant or breastfeeding, speak with a healthcare professional before considering treatment.
There are also medical conditions and medicines that may affect whether Wegovy or Mounjaro is suitable for you. This is why a clinical assessment is important before treatment.
Your suitability for either medicine should be assessed individually. It should not be decided simply by comparing needle systems, trial results or BMI alone.
Getting Started with EverydayMeds
Whichever treatment you are considering, treatment begins with a free online clinical consultation with our UK registered prescribing team. A healthcare provider reviews your medical history and current medicines before deciding whether treatment may be suitable for you.
They can also explain how your specific pen works, what supplies you need, how to follow the injection instructions and what to do if you have questions about your treatment.
All treatment is dispensed by our GPhC registered pharmacy in accordance with applicable UK requirements.
Medical Disclaimer
This page provides general information about Wegovy and Mounjaro pen and needle systems. It is not a substitute for personalised medical advice.
Always follow the patient information leaflet supplied with your prescribed product. If you are unsure which needle to use, how to attach it, how to inject or how to dispose of it, speak with your prescriber or pharmacist before using the pen.
