Weight loss injection yearly cost calculator UK

A worked example

Take a patient on Mounjaro 10 mg who expects to stay at 10 mg for a year. On 21 October 2026 the cheapest ongoing price for a 10 mg pen was £203.00 at G-1 Nutrition (GPhC 9010938). Each pen holds four weekly doses, so one pen is one month and twelve pens cover 48 weeks. The year costs 12 multiplied by £203.00, which is £2,436.00.

The median ongoing price for the same pen across 80 registered pharmacies was £259.00. Twelve pens at the median cost £3,108.00. The difference between the cheapest and the median pharmacy over the year is £672.00, for the same medicine at the same dose.

The cheapest discount price for a first order at 10 mg was £188.00 at New Health (GPhC 9011199) with code MONJ12. Using it for the first pen and the cheapest ongoing price for the other eleven moves the total by the difference on one pen only.

The same arithmetic for the other medicines at their highest doses gives £2,808.00 for Mounjaro 15 mg (£234.00 a pen), £1,668.00 for Wegovy 2.4 mg (£139.00), £2,398.56 for Wegovy 7.2 mg (£199.88), £1,235.88 for the Wegovy pill 25 mg (£102.99) and £1,679.40 for Foundayo 17.2 mg (£139.95).

What the calculator does

The calculator takes a medicine, a dose and a number of months, and multiplies the number of months by the cheapest ongoing price and by the median ongoing price for that dose. It shows both totals and the difference between them. It can also take a dose schedule, with a number of months at each dose, and sum the stages. The schedule matters in a first year, because the SmPC for Mounjaro and Wegovy sets a minimum of four weeks at each step before any increase, and a first year following that minimum costs less than a year spent at the top dose.

The calculator is a budgeting aid. It does not suggest a dose or a schedule. Which dose you are on and how long you stay there is set by your prescriber.

Who the totals apply to

Private patients in England, Scotland, Wales and Northern Ireland. An NHS patient in England pays £9.90 per prescription item, so twelve pens cost £118.80, or £114.50 with a 12-month prepayment certificate. In Scotland, Wales and Northern Ireland NHS prescriptions are free. NHS access is limited to Mounjaro through a phased GP rollout and Wegovy through specialist services, set out in the NHS weight loss injections guide. The Wegovy pill and Foundayo are not available on the NHS.

Method

1. Prices are taken from the GLP Index export of 21 October 2026. For each medicine and dose the index records the cheapest and median ongoing price across every registered pharmacy listed: 80 for Mounjaro, 72 for the Wegovy injection, 56 for the Wegovy pill and 32 for Foundayo.
2. Each price covers a four-week supply, the prescriber consultation and standard delivery.
3. A month is treated as one four-week supply. Twelve supplies cover 48 weeks. A calendar year of 52 weeks needs 13 supplies, and the calculator lets you set 13 months if you want the 52-week figure.
4. The ongoing price is used for every month, including the first. The first order price is a one-off and is shown separately on the price pages.
5. Totals are arithmetic on the index figures and assume no price change through the period. Prices change, so a total is a snapshot of 21 October 2026.
6. Extras charged by some pharmacies, such as express delivery, sharps bins, blood tests and additional consultations, are not included. The what the price includes guide lists them.

Mistakes that cost money

Budgeting on the first order price for twelve months. Budgeting at the starting dose when the prescriber's plan moves through the steps, so the bill rises every four weeks for the first five months of Mounjaro. Forgetting the 13th supply in a 52-week year. Choosing a pharmacy from the first order column rather than the ongoing column, which the first order and ongoing guide explains. Signing a 3, 6 or 12 month plan to fix the total: the Dose Club does not advise tie-in plans, because the prices are higher and most of the benefit sits with the pharmacy. See subscription against pay monthly.

Where the figures come from

All prices are from the GLP Index export of 21 October 2026. The four-week minimum per dose step is from the Mounjaro and Wegovy Summaries of Product Characteristics on emc. The NHS prescription charge is from the NHS website and the prepayment certificate price from NHSBSA. Free prescriptions in Scotland, Wales and Northern Ireland are from NHS inform, the Welsh Government and nidirect.