Why Mounjaro costs more as your dose goes up
Mounjaro comes as a KwikPen holding four weekly doses, and each strength is a separate pen. Pharmacies pay more for the higher strengths. The NHS Drug Tariff, which sets what the NHS reimburses pharmacies, puts the 2.5 mg pen at £133 and the 12.5 mg and 15 mg pens at £330.
Private prices follow the same shape. That's why the price of your first pen is a poor guide to what you'll pay. Most people step up every four weeks until they reach the dose that works for them, then stay there. Read how the dose schedule works.
The September 2025 Mounjaro price rise
Eli Lilly raised the UK list price of Mounjaro from 1 September 2025. The NHS reimbursement prices were redetermined at the same time so that pharmacies wouldn't dispense at a loss.
| Pen strength | Before 1 September 2025 | From 1 September 2025 |
|---|---|---|
| 2.5 mg | £92 | £133 |
| 5 mg | £92 | £180 |
| 7.5 mg | £107 | £255 |
| 10 mg | £107 | £255 |
| 12.5 mg | £122 | £330 |
| 15 mg | £122 | £330 |
Providers handled the change differently. Some kept old prices on pens they already had in stock, and some changed prices a month later. We haven't found any announced change to the UK list price since September 2025.
What should the price include?
Two prices that look the same can cover different things. Before you compare, check whether the price includes:
- the consultation and any follow-up reviews with a prescriber
- delivery to Northern Ireland, and whether it's tracked and temperature-controlled
- one pen (four weekly doses) or more
- needles, a sharps bin and any support such as coaching or a dietitian
Our comparison shows what each provider says is included, and flags where it isn't stated.
Can you get Mounjaro on the NHS in Northern Ireland?
Not routinely. The Department of Health has announced a phased Regional Obesity Management Service, starting with adults who have a BMI over 45 and at least one related condition. For most people, Mounjaro in Northern Ireland is a private prescription. Read the NHS in NI guide.
How to pay less without taking risks
- Compare the cost of a year, not a month. The cheapest starting pen isn't always the cheapest course. Use the cost calculator with the dose you expect to reach.
- Ask NI pharmacies for a quote. Most local pharmacies don't publish prices online, so a phone call is the only way to compare them.
- Ask about longer plans. Some providers charge less per pen if you commit to 3, 6 or 12 months. Find out what happens if you need to stop early, for example because of side effects, before you sign up.
- Be wary of prices that look too good. The MHRA warns that prescription weight loss medicines are being sold illegally online and on social media. Only buy from a registered pharmacy after a proper consultation. How to buy safely.
- Don't change your dose to save money without talking to your prescriber.