Mounjaro Starter Pack UK: What's Included and What It Costs (October 2026)

01 · What you get

What is in a Mounjaro starter pack?

A Mounjaro starter pack is the 2.5mg KwikPen followed by the 5mg KwikPen, which together make up the first eight weeks of treatment. Mounjaro is the brand name for tirzepatide, a once-weekly injection made by Eli Lilly and licensed in the UK for weight management in adults. It comes as a pre-filled multi-dose pen in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

Eli Lilly supplies pens, not a branded starter box, so the contents of any 'pack' depend on the pharmacy. With us, the practical starter route is:

• Pen 1: 2.5mg. Four weekly doses. Everyone begins here.
• Pen 2: 5mg. Four weekly doses, taken once your prescriber agrees you can step up after at least four weeks.
• Supplies. Needles, a sharps bin and injection guidance are included with every order.

Each KwikPen contains four weekly doses, so one pen is one month of injections.¹ If you want to see how a two-pen bundle is framed, our 2-month starter pack page walks through it, and a longer plan is covered in the 3-month starter pack guide.

02 · Cost

How much does a Mounjaro starter pack cost?

Your first Mounjaro 2.5mg pen costs £129.99 with code FIRST40; the standard 2.5mg price is £169.99. The 5mg pen that follows is £189.99 at the standard price. A new-customer discount applies to your first order at any dose, and an automatic £25 reorder discount applies to every future order (code DOSE25), so the second pen is £25 off the standard price.

For context, across the UK pharmacies we track, the cheapest 2.5mg starting pen is £143.96 and the dearest is £179.99 (checked 25 October 2026). For the same dose, the gap between providers ranges from £20 to £36.03. When you compare, check that the quoted figure is the price you actually pay, and whether needles and a sharps bin are included. With us the consultation is free and there are no hidden fees: the price shown is the price paid.

If you are already on a higher dose with another provider and are switching, the same first-order discount applies at any dose. At 15mg your first order is £259.99.

03 · Bundle or single pen

Starter pack or one pen at a time?

Buying pen by pen is usually the safer structure, because your dose depends on how you respond, not on a fixed schedule. The licensed ladder is 2.5mg for at least four weeks, then 5mg, then steps of 2.5mg at minimum four-week intervals, up to 15mg.¹ Your prescriber guides the pace, so a pre-committed multi-month bundle can end up holding the wrong strength.

All totals are at standard prices before discounts. A new customer's first order is £40 less, and every later order is £25 less. Our starter bundle page covers bundle-style purchasing in more detail, and the starter bundle price guide goes deeper on costs.

04 · How to order

How ordering works

Ordering takes four steps.

• 1. Free online consultation. A short health questionnaire, no charge and no obligation.
• 2. Prescriber review. A GPhC-registered prescriber reviews it, not a scoring script. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• 3. Dispensing and dispatch. Our registered pharmacy dispenses your pen, with same-day dispatch when ordered by 3pm.
• 4. Delivery. Free next-day tracked delivery in temperature-controlled, discreet packaging. Saturday delivery is £14.99.

All six doses are in stock, supplied through official LillyDirect supply, which means genuine KwikPens direct from Eli Lilly's UK distribution. Start your free consultation here. Klarna and pay-monthly options are available, with no subscriptions.

05 · Your first eight weeks

What the first eight weeks look like

Everyone starts Mounjaro on 2.5mg once a week, and that starting dose is about letting your body adjust, not about weight loss itself.¹ After at least four weeks the dose increases to 5mg. From there it can rise by 2.5mg at minimum four-week intervals (7.5mg, 10mg, 12.5mg) up to a maximum of 15mg weekly, depending on how you respond and tolerate it.¹¹

Many people settle at a maintenance dose of 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber will guide the right pace. You can read more on the Mounjaro starter dose page.

06 · Injecting and dosing

Injecting your first pen

Mounjaro is injected under the skin once a week, on the same day each week, at any time of day, with or without food.¹ There is no best time of day: it works the same morning or evening. What matters is the same day every week. Many people choose a weekend morning so early side effects fall on days off.

Licensed injection sites are the stomach area (at least 5cm from the belly button), the front of the thigh, or the back of the upper arm if someone else gives the injection. Rotate the site with each dose.¹³

Missed a dose? Take it as soon as you can within 4 days (96 hours) of the scheduled time. If more than 4 days have passed, skip it and take the next one on your normal day. Never take two doses within 3 days of each other.¹ You can also change your injection day, as long as at least 3 days (72 hours) have passed since your last dose.¹

07 · Storage and travel

Storage, the 30-day rule and travel

Keep pens in a fridge at 2–8°C and never freeze them. Once in use, a pen can be kept out of the fridge not above 30°C for up to 30 days, after which it should be discarded.¹ A pen holds four weekly doses, so a pen used weekly is finished within that window. Keep the cap on to protect it from light, and never use a pen that has been frozen.¹³

Unopened pens stay in the fridge and keep until the expiry date printed on the box. If an unopened pen has been out of the fridge, check with the pharmacy before using it rather than relying on a remembered day limit, because figures circulating online often come from other countries' labels.¹³

You can fly with Mounjaro. Carry pens in hand luggage, because hold luggage can fall below freezing, ideally in a cool bag with the prescription label or a copy of your prescription. Most holidays need no special arrangements, though hot climates call for an insulated pouch.¹ Our guides on how to pack Mounjaro for travel and whether you can pack Mounjaro in a suitcase cover the practical detail.

08 · Realistic results

How much weight can you lose in the first three months?

Three months in, most people are still on the lower rungs of the dose ladder, so trial-average losses at this stage are modest compared with the headline figures: a sensible 3-month expectation on a standard titration is mid single digits as a percentage of body weight, with wide individual variation. The first weeks on 2.5mg are an adjustment phase and losses are usually modest. Most measurable progress builds from 5mg onward, month by month.¹ Some people notice appetite change and early loss in week one, while others feel little until a higher dose, and both are normal. Early loss includes water weight, so judge the trend over weeks rather than any single weigh-in.

The trial evidence is measured over 72 weeks. In SURMOUNT-1 (2,539 adults), people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg, compared with 3.1% with lifestyle changes alone.² For someone starting at 100 kg, 20.9% is about 21 kg. These are trial averages, individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.

Your response is reviewed by your prescriber. If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, they will discuss whether continuing or stopping is right for you.¹ Common early effects are mild nausea, altered appetite and tiredness in the first days after each injection, which usually settle.¹

09 · Who can start

Who can use a starter pack, and the NHS picture

Mounjaro is licensed for weight management in adults with a BMI of 30 or above, or a BMI between 27 and 30 with at least one weight-related condition such as high blood pressure, high cholesterol, obstructive sleep apnoea, cardiovascular disease, prediabetes or type 2 diabetes. It must be used alongside a reduced-calorie diet and increased physical activity. A prescriber assesses your BMI, medical history and current medicines before deciding whether it is suitable.¹

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions).⁴⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

Whichever route you take, only buy from a pharmacy you can verify on the GPhC register. Our registration number is 9012878. Be wary of anyone offering to supply without a consultation or prescription. The MHRA publishes counterfeit medicine alerts, and you can report any suspected side effect through the Yellow Card scheme.⁷¹⁹

10 · Dose safety

What to avoid in your first weeks

The main thing to avoid is changing the dosing yourself: do not stretch, split or skip doses.

Also avoid doubling up after a missed dose (never two doses within 3 days of each other), freezing the pen, and using a pen that has been above 30°C or has been out of the fridge for more than 30 days in use. Because tirzepatide slows stomach emptying, it can reduce how well oral contraceptive pills are absorbed. The SmPC advises switching to a non-oral method, or adding a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.¹ If you take insulin or sulfonylureas, tell the prescriber, because doses may need adjusting to avoid low blood sugar.¹

Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. This page is information, not a substitute for medical advice. For a fuller walkthrough, see our step-by-step starter guide and the starter kit overview, or browse our weight loss clinic.

11 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹