Mounjaro 2.5mg and 5mg Bundle: The First Eight Weeks (October 2026)

01 · Cost

What the first two pens cost

The first two pens cost £169.99 for 2.5mg and £218.99 for 5mg at standard prices, per 4-week pen. You can see both on the Mounjaro pen page, with all six doses in stock.

A new customer's first order is £40 less with code FIRST40, at any dose. After that, every later order is £25 off the standard price (code DOSE25). Your first 2.5mg pen therefore costs £129.99.

We price each pen individually and show that price openly, with a free consultation and no hidden fees. If you want to compare providers first, our guide to the price of Mounjaro 2.5mg shows how starting-pen prices differ across the UK pharmacies we track.

02 · Safety

Can you take 2.5mg and 5mg together?

No: the licensed schedule is one weekly dose, and the dose moves up from 2.5mg to 5mg only after at least 4 weeks.¹ The two pens are consecutive steps, not a combined dose.

Combining pens, or dialling part-doses to build a different strength, is outside the licence. The pen's design does not support it and there is no safety data on it.¹ If you are wondering about splitting a dose, see why half a 5mg dose is not 2.5mg.

03 · How to order

How ordering works

Ordering takes three steps, starting with a free online consultation.

• Complete the short health questionnaire: free, no obligation.
• A GPhC-registered prescriber reviews it. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• We dispense and dispatch; same-day dispatch applies when ordered by 3pm, with free next-day tracked delivery in temperature-controlled packaging.

Repeat orders re-check suitability and nothing ships automatically, so you step up to 5mg once your prescriber agrees. Needles, a sharps bin and injection guidance come with every order. Mounjaro slows stomach emptying, which 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. Mounjaro must not be used during pregnancy, and it should be stopped at least one month before trying to conceive.

04 · When to move to 5mg

When to move from 2.5mg to 5mg

You move up after at least 4 weeks on 2.5mg, which is one full pen of four weekly doses.¹ The 2.5mg dose is about letting your body adjust, not about weight loss itself. From 5mg, the dose can then rise in 2.5mg steps at minimum 4-week intervals, depending on response and tolerance.¹

Our guide to moving from 2.5mg to 5mg covers the decision in more detail. If nausea is troubling you, read about nausea on 2.5mg and speak to your prescriber before stepping up.

05 · 5mg versus 2.5mg results

Do you lose more on 5mg than 2.5mg?

Results are built mainly from 5mg onward, because 2.5mg is an adjustment phase and early losses are usually modest.¹ In the SURMOUNT-1 trial of 2,539 adults, people on 5mg lost on average 15% of their body weight over 72 weeks, against 3.1% with lifestyle changes alone; individual results vary.² For someone starting at 100 kg, 15% is about 15 kg.

Think in months, not days, and judge progress by trend rather than single weigh-ins. For what the first month can look like, see Mounjaro before and after one month.

06 · Using your pens safely

Using the pens safely

Inject once a week on the same day, at any time of day, with or without food; there is no best time.¹

Store unused pens in the fridge. Once in use, a pen can be kept out of the fridge at a temperature not above 30°C for up to 30 days after first use, and must then be thrown away.¹ Buy only from a registered pharmacy; our GPhC registration is 9012878. Be wary of anyone offering to supply without a consultation or prescription, and report suspected fakes through the Yellow Card scheme.⁷ 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.