Starting Mounjaro for the first time involves more than finding a first order discount. New customers can currently receive £40 off their first eligible Mounjaro order with code FIRST40 at checkout. This brings the listed price of a 2.5mg starter pen from £169.99 to £129.99.
If you are considering tirzepatide for weight management in the UK, you may also have questions about what happens after you complete the consultation, whether treatment may be suitable for you, what is included in your order, how Mounjaro should be stored, and what you might experience during the first few weeks. It is also useful to understand the ongoing cost once the first order discount has been used.
That is what this page covers. You can find out how to use the discount code, how the online consultation and prescription process works, what to expect from delivery and storage, possible early side effects, eligibility, ongoing pricing, and the key points to consider before ordering.
The discount can help reduce the cost of your first order, but your health and suitability for treatment should come first. A prescriber will assess whether Mounjaro is appropriate for you before it can be supplied.
If you are mainly comparing prices across pharmacies, our Mounjaro discount code and pricing guide sets out the full price list and how to compare offers.
The First Order Offer, in Full
| Detail | |
|---|---|
| Code | FIRST40 |
| Saving | £40 off your first order |
| Who qualifies | New customers, one use |
| Applies to | All Mounjaro pens and bundles |
| Delivery | Free and tracked, no code required |
| After your first order | £25 off every subsequent order |
Worth noting: savings may continue beyond the first order through the returning-customer discount . Every repeat order currently carries a £25 discount, which may provide greater overall savings for people who continue treatment long term .
First Order Prices
| Pen strength | Standard | With FIRST40 |
|---|---|---|
| 2.5mg | £169.99 | £129.99 |
| 5mg | £199.99 | £159.99 |
| 7.5mg | £249.99 | £209.99 |
| 10mg | £269.99 | £229.99 |
Each pen contains four weekly doses and is intended to cover four weeks of treatment when used as prescribed. Bundles combining consecutive strengths may also be available and may form part of a weight management package. The live pricing table on the product page takes precedence over any prices quoted here, as prices and offers can change.
The strength that is appropriate for you, including your starting dose and any later changes, is decided by your prescriber based on your clinical assessment and response to treatment. It is not something you should choose based on price alone.
What Happens After You Order, Step by Step
Step 1. The online consultation
Mounjaro can only be supplied following a clinical assessment. The online consultation takes a few minutes and forms part of the medical review process.
You will be asked about your height and weight, medical history, current medicines, previous weight management attempts, and other information that may affect whether Mounjaro is suitable for you. The prescriber will also consider relevant contraindications and the licensed prescribing criteria for weight management.
Answer the questions as accurately and completely as you can, including information about any existing conditions or medicines. If more information is needed, the prescriber may contact you with follow up questions before making a decision.
A clinical assessment is required when treatment is requested, including for repeat supplies.
Step 2. Prescriber review
A UK registered prescriber typically reviews assessments within 3 working days. Express review may be available, with a stated review time of up to 24 hours.
There are several possible outcomes. The prescriber may approve treatment, ask for more information before making a decision, or decide that Mounjaro is not suitable for you. If treatment is not approved and the medicine is not supplied, you are not charged for the medicine.
Step 3. Dispensing and delivery
If your prescription is approved, the order is dispensed by the GPhC registered pharmacy and sent with free tracked delivery. Plain packaging may be used, without an indication of the medicine contents on the outside.
Because Mounjaro is temperature sensitive, it is sent in insulated packaging designed to help maintain the required temperature during delivery. Tracking allows you to monitor the delivery and plan for its arrival.
Step 4. Ongoing support
Repeat supplies are subject to further clinical checks rather than being treated as automatic reorders. These checks allow your treatment to be reviewed over time.
The pharmacy team can help with treatment related questions between orders where appropriate. Any change in strength should be decided by your prescriber based on factors such as your response to treatment, tolerability, and individual circumstances.
Everyone responds differently to weight management treatment, so the timing of dose changes and your treatment plan may vary from person to person.
What Arrives, and How to Store Mounjaro
Your first order contains the Mounjaro KwikPen at the strength prescribed, needles for use with the pen, and the manufacturer's patient information leaflet.
Read the leaflet before using your first injection. It provides important information about how to use the pen, how to store it, and possible side effects. Always follow the instructions supplied with your medicine.
Storage in brief:
- Unopened pens should be stored in a refrigerator
- Once in use, a Mounjaro pen may be kept at room temperature for up to 30 days, according to the product information
- Do not freeze the pen, and do not use it if it has been frozen
- Keep the pen in its original carton and protect it from light
- Dispose of used needles in a sharps bin rather than household waste
If your delivery is delayed or you are unsure whether the required temperature was maintained during delivery, contact the pharmacy before using the pen. Do not rely on guesswork when it comes to storing temperature sensitive medicine.
What the First Few Weeks Are Like
Everyone responds differently to Mounjaro, so your experience during the first few weeks may not be the same as someone else's.
Some people notice changes in appetite after starting treatment. You may also notice that you feel fuller after eating or feel less hungry between meals. Mounjaro is taken once a week, and taking it on the same day each week can help you keep track of your scheduled dose.
Gastrointestinal side effects are among the most commonly reported. These can include nausea, constipation, diarrhoea, indigestion, vomiting, and reduced appetite. Side effects may be more noticeable when you first start treatment or after your dose is increased, although this varies from person to person.
Some people find that side effects become less noticeable over time. Eating smaller portions, stopping when you feel full, and drinking enough fluids may help you manage some digestive symptoms. Mounjaro can also cause injection site reactions, such as redness, itching, or swelling.
Do not expect your weight to change dramatically within the first few weeks. Clinical trial results are measured over much longer periods, such as 72 weeks, and individual results can vary.
If you have a missed dose, take it as soon as possible within 4 days, or 96 hours. If more than 4 days have passed, skip the missed dose and take your next dose on your usual day. Do not take two doses within 3 days, or 72 hours, of each other.
Contact your prescriber, GP, or NHS 111 if you experience:
- Severe or persistent abdominal pain, particularly if the pain spreads to your back
- Persistent vomiting or signs of dehydration
- Symptoms of low blood sugar, particularly if you also take insulin or a sulfonylurea
- A side effect that concerns you, is severe, or does not improve
Suspected side effects can also be reported through the MHRA Yellow Card scheme.
One Thing to Discuss During Your Consultation
The MHRA issued advice in June 2025 concerning tirzepatide and oral contraception. Because tirzepatide can delay gastric emptying, it may affect the absorption of oral contraceptives. Additional contraception or a non oral contraceptive method is advised for four weeks after starting treatment and for four weeks after each dose increase.
If this applies to you, mention it during your assessment so your prescriber can discuss the appropriate options with you.
What Mounjaro for Weight Loss Is
Mounjaro (tirzepatide) is manufactured by Eli Lilly and is licensed in the UK for weight management in eligible adults alongside dietary and lifestyle changes. It is a prescription only medicine and is also licensed for the treatment of type 2 diabetes.
If you are wondering how Mounjaro works, tirzepatide acts on two gut hormone receptors, GIP and GLP 1, rather than the single GLP 1 receptor targeted by medicines such as semaglutide. These hormones are involved in appetite regulation and blood glucose control.
GIP stands for glucose dependent insulinotropic polypeptide. Together, GIP and GLP 1 can affect appetite signalling, feelings of fullness after eating, and how quickly the stomach empties. These effects may help some people manage their weight when Mounjaro is used alongside dietary and lifestyle changes.
Mounjaro is intended to be used as part of a wider weight management plan, rather than as a replacement for healthy eating and physical activity. Maintaining healthy lifestyle habits can remain an important part of managing your weight during and after treatment.
The Evidence and Side Effects of Mounjaro
SURMOUNT 1 followed adults with obesity, or overweight with a weight related health condition, for 72 weeks. In the trial, around 91 per cent of participants receiving tirzepatide achieved at least 5 per cent weight reduction. Mean weight reduction at the highest dose was around 20 per cent, while lower doses were associated with smaller average reductions.
These are average results from a clinical study and do not predict how much weight an individual person will lose. Results can vary considerably between people.
SURMOUNT 5 compared tirzepatide with semaglutide directly over 72 weeks. The study reported mean weight reductions of 20.2 per cent with tirzepatide and 13.7 per cent with semaglutide. These figures are population averages rather than a prediction for an individual. The most suitable treatment can depend on your medical history, existing conditions, other medicines, and how you respond to treatment.
NICE TA1026, published in December 2024, recommends tirzepatide as an option for managing overweight and obesity in eligible adults alongside diet and increased physical activity. NICE also recommends reviewing treatment if less than 5 per cent of initial body weight has been lost after 6 months on the highest tolerated dose.
Weight management goals vary from person to person. The dose you remain on for longer term treatment depends on factors such as your response to treatment and tolerability, and should be decided by your prescriber.
For context, Health Survey for England data records 29 per cent of adults living with obesity and 64 per cent as overweight or living with obesity.
Who Can Be Prescribed Mounjaro
For weight management, the licensed criteria generally include a BMI of 30 or above, or a BMI of 27 or above with at least one weight related health condition. Examples include high blood pressure, dyslipidaemia, obstructive sleep apnoea, cardiovascular disease, prediabetes, or type 2 diabetes.
Mounjaro may not be suitable for everyone. Your prescriber will consider factors such as pregnancy, breastfeeding, plans to become pregnant, your medical history, and any medicines you currently take. Certain medical conditions or previous health problems may also affect whether treatment is appropriate.
These are general eligibility criteria and are not intended to replace a clinical assessment. Meeting the BMI criteria does not automatically mean that Mounjaro will be prescribed. Your prescriber will assess your individual circumstances and decide whether treatment is appropriate.
Mounjaro is one of several medicines that may be considered for weight management. Your treatment should be based on an individual clinical assessment rather than self diagnosis.
Could I get it on the NHS instead?
Possibly, but NHS access is more limited than the wider licensed criteria for Mounjaro. NHS access for weight management began a phased rollout in March 2025 through specialist weight management services, with access being extended gradually into primary care. The rollout prioritises people with the highest clinical need.
BMI thresholds can be 2.5 kg/m² lower for people from South Asian, Chinese, other Asian, Middle Eastern, Black African, or African Caribbean backgrounds.
If you think you may qualify for NHS treatment, speak to your GP. They can check the current eligibility criteria and explain what NHS weight management services are available in your area.
If you think you might qualify, asking your GP costs nothing. Our overview of medically supervised weight loss covers the alternatives if you do not.
Budgeting Beyond the First Order
One common mistake when starting Mounjaro is to plan your budget around the first order price alone. Depending on the prescribed strength and how long treatment continues, six months of treatment may cost around £1,478 at current pricing. This makes it useful to look at the potential ongoing cost rather than only the introductory offer. Prices can vary between providers and may change over time.
A practical approach is to work out the cost of your first twelve weeks based on the strengths you may be prescribed, including the £25 repeat discount available from the second eligible order onwards. This gives you a better idea of the ongoing cost than using the £129.99 first order price as your main guide. Your prescriber can also explain how your treatment may progress after your clinical assessment.
Treatment length varies from person to person and should be reviewed regularly with your prescriber. There is no subscription lock in or obligation to continue treatment, but if you are considering stopping Mounjaro, it is sensible to discuss this with your prescriber first.
When planning your budget, consider the potential cost of treatment over several months rather than focusing only on the starting strength and first order discount.
Key Takeaways
- FIRST40 takes £40 off an eligible first order, bringing a 2.5mg pen to £129.99 at the current listed price
- Clinical assessment, prescription, needles, and tracked delivery are included according to the current offer
- Prescriber review is typically completed within 3 working days, or within 24 hours where express review is available
- If treatment is not approved and the medicine is not supplied, you will not be charged for the medicine
- Eligible returning customers can receive a £25 discount on subsequent orders
- Your prescribed strength and any dose changes are clinical decisions made by your prescriber
- When budgeting, look at the cost over your first twelve weeks and beyond rather than focusing only on the introductory price
