Questions about how much metformin costs the NHS, what UK patients pay, and how it compares with Mounjaro usually come from one of two places: someone who has recently been prescribed metformin and wants to know what it might cost, or someone comparing treatments and noticing a large difference in price. The short answer is that metformin is generally a low cost medicine used by the NHS. A month of standard release 500mg tablets is listed at well under £1, and many people treated for diabetes do not pay for their NHS prescriptions.
For UK adults trying to understand both the NHS price and their own likely cost, the detail matters because NHS medicine prices, prescription charges and exemption rules are not the same thing. In England, many people treated with medication for diabetes can apply for a medical exemption certificate, while NHS prescriptions are free for everyone in Scotland, Wales and Northern Ireland.
This guide explains what metformin can cost a patient, what the NHS pays for it, how prescription charges work across the UK, how NHS spending on diabetes medicines fits into the wider picture, and how metformin compares with Mounjaro. They are licensed for different uses, so their prices are not a like for like comparison. Both are prescription only medicines, and suitability depends on an individual clinical assessment.
Key things to know
- The NHS prescription charge in England is £9.90 per item for 2026/27, frozen for a second year
- That charge is the same whatever the medicine costs, so it is not the actual price of metformin
- People treated with medication for diabetes can apply for a medical exemption certificate and, if eligible, pay nothing for their NHS prescriptions
- Metformin is licensed for type 2 diabetes, not for weight management
- Mounjaro is licensed for both type 2 diabetes and weight management, and belongs to a different class of medicine
How Much Is Metformin in the UK?
What you pay depends more on where you live and whether you are exempt than on the price of the medicine itself. Searches such as how much is metformin UK, how much does metformin cost UK, the cost of metformin UK, metformin UK price, what is the cost of metformin, how much is metformin cost, or simply price metformin and cost metformin, all lead back to the same basic set of rules.
| Your situation | What you pay for metformin |
|---|---|
| England, no exemption | £9.90 per item, per prescription |
| England, medical exemption certificate | Nothing |
| England, prepayment certificate | £32.05 for 3 months or £114.50 for 12 months, covering all items |
| Scotland, Wales, Northern Ireland | Nothing |
| Private prescription | The pharmacy's own price, plus any prescription fee |
Most people taking metformin pay nothing
This is a point that is often misunderstood online. In England, a person with diabetes who is treated with medication can apply for a medical exemption certificate. If approved, the certificate makes their NHS prescriptions free, not only prescriptions for diabetes. Anyone prescribed metformin for diabetes may therefore be eligible.
The certificate has to be applied for and renewed when required. It does not normally cover charges from before the certificate was issued, so it is worth checking your eligibility and applying as soon as you can.
Prescription charges apply only in England. Scotland, Wales and Northern Ireland do not charge for NHS prescriptions, so many patients across the UK do not pay for their metformin prescription. Across all medicines, a large proportion of prescription items dispensed in England are also provided free of charge.
If you do pay, the charge is not the price of the medicine
The £9.90 charge is a flat fee per item. It does not reflect the actual cost of the medicine, which means the metformin prescription charge can be much higher than the value of the tablets themselves.
If you regularly pay for more than 11 prescription items a year, a prepayment certificate may work out cheaper. It can also be paid for by monthly direct debit, which may make budgeting easier.
Metformin Tablets 500 mg Price and Metformin Tablets 1000 mg Price UK
The actual price of metformin, rather than what a patient is charged, is published in the NHS Drug Tariff. Standard release metformin 500mg tablets have been listed at well under £1 for a pack of 28. Modified release versions cost a little more but remain relatively low, with metformin 1g modified release listed at around £2 for 56 tablets and metformin 500mg modified release at around £1.36 for 56 as of April 2026.
So, the metformin 500 mg price and the metformin 1000 mg price that UK pharmacies are reimbursed at are measured in pennies per tablet. These are generic prices that can change over time, so treat any figure as a snapshot rather than a fixed price. Temporary supply issues can also result in concession prices being used.
That is the simple answer to the question, is metformin expensive? At the medicine price level, it is generally a low cost medicine. Metformin has been available as a generic medicine for decades, and several manufacturers produce it.
How Much Does Metformin Cost the NHS?
The cost of each prescription is low, but total NHS spending can be significant because metformin is prescribed to a large number of people. Metformin hydrochloride is one of the most commonly prescribed diabetes medicines in England, with tens of millions of items dispensed each year.
The NHS Business Services Authority publishes figures on prescription items and spending. In 2024/25, there were 77 million items prescribed for treating diabetes in England, at a cost of £1.92 billion, roughly double the figure of ten years earlier. Antidiabetic drugs accounted for more than 58 million of those items at £1.1 billion, an 11 per cent rise in items and an 18 per cent rise in cost on the previous year. An estimated 3.9 million people received diabetes related prescriptions, up 7 per cent year on year.
Metformin's low medicine cost is only one part of the wider picture. Diabetes treatment can also involve other medicines, monitoring, appointments and care for complications.
The detail that matters for this comparison is what is contributing to the increase in spending. The NHSBSA identified tirzepatide, the active ingredient in Mounjaro, alongside dapagliflozin, as medicines contributing to increases in costs. Metformin accounts for a large number of prescription items but has a relatively low cost per item. Some newer medicines have a much higher cost per item.
Which Oral Antidiabetic Agents Have the Most Favourable NHS/Hospital Procurement Prices?
There is no single published list of negotiated NHS prices, so it would be misleading to give a definite ranking. Community pharmacy reimbursement works through the Drug Tariff, where prices for established generic medicines are reviewed and updated. Hospital procurement uses separate national and regional contracts, and some contract prices are commercially confidential.
Outside NHS supply, metformin is also available through registered online pharmacies. Metformin tablets can start from £7.15 online without an NHS prescription if you choose to buy metformin privately. Online providers usually ask for a medical questionnaire before supply so that a prescriber can assess whether the medicine is suitable. Some providers may also limit private supply to people who are already taking metformin under the care of their GP.
More generally, established generic oral medicines tend to be lower cost. Metformin is a clear example, with gliclazide and other sulfonylureas also listed at well under £1 for a month's supply, and pioglitazone similarly inexpensive. Some newer branded classes cost considerably more per patient. Dapagliflozin was the highest cost single chemical substance in England's 2024/25 Prescription Cost Analysis at £333 million, despite being prescribed to far fewer people than metformin.
This is also part of the wider cost picture for type 2 diabetes medicines. Lower cost medicines may be used alongside newer, more expensive options when clinically appropriate. Cost is one consideration in prescribing, alongside NICE guidance, cardiovascular and kidney risk, other health factors and individual suitability.
How Much Is Metformin Without Insurance?
Searches for how much is metformin without insurance, or what is the cost of metformin without insurance, often come from health systems where medicines are paid for through insurance. The UK does not generally work that way, so the question does not translate directly.
There is no insurance layer on NHS prescriptions. You either pay the standard charge in England, qualify for an exemption, or live in a UK nation where NHS prescriptions are free. Private medical insurance in the UK generally does not cover routine repeat prescriptions for long term conditions, so it would not usually be the main way people pay for metformin.
In practical terms, the amount you pay for NHS metformin depends mainly on your location and exemption status. For many people, the cost is nothing.
Metformin vs Mounjaro: Two Different Medicines for Blood Sugar Control
The metformin vs Mounjaro comparison is sometimes presented as a cheap option against an expensive option, but that can give the wrong impression. They belong to different medicine classes and have different licences, so one should not automatically be viewed as a replacement for the other.
| Metformin | Mounjaro | |
|---|---|---|
| Active ingredient | Metformin hydrochloride | Tirzepatide |
| Class | Biguanide | Dual GIP and GLP 1 receptor agonist |
| How it is taken | Oral tablet, usually daily | Once weekly injection |
| Licensed for | Type 2 diabetes | Type 2 diabetes and weight management |
| Licensed for weight loss | No | Yes, in eligible adults |
| Storage | Room temperature | Fridge, 2°C to 8°C |
| Typical patient cost | Prescription charge or nothing | Full private cost unless NHS criteria are met |
Metformin is commonly used as a first line medicine for type 2 diabetes in UK guidance. It works in several ways to help control blood glucose, including reducing the amount of glucose produced by the liver and improving the body's response to insulin. It is not licensed as a weight management medicine, although some people may experience a small change in weight while taking it.
Tirzepatide acts on two gut hormone pathways, GIP and GLP 1, which are involved in blood glucose control and appetite. In a 72 week clinical trial in adults with obesity or overweight and at least one weight related condition, average body weight reduction of up to 20.9 per cent was observed at the highest dose. This was an average result from a specific clinical trial, and individual results can differ.
Some people may be prescribed both medicines. This is another reason why the comparison is better treated as a clinical question rather than simply a price comparison. Your prescriber can assess which treatment or combination may be appropriate for you.
Why the Price Gap Is So Large
Several factors help explain the difference in price. Metformin has been available as a generic medicine for many years and is made by multiple manufacturers. This contributes to its relatively low medicine price. Tirzepatide is a newer medicine, and the costs associated with its manufacture and supply are different.
The formulations are also different. Metformin is an oral tablet, while Mounjaro is supplied as an injection pen that needs to be stored in a refrigerator under the recommended conditions.
There is also a difference in NHS access. Metformin is routinely prescribed for type 2 diabetes, while access to tirzepatide through the NHS for weight management is subject to specific eligibility criteria and phased implementation. This means that many people considering Mounjaro privately may need to pay the full private price.
If you are weighing up weight loss treatment options, the route through which you access treatment can have a significant effect on what you actually pay.
What Mounjaro Costs Privately
For comparison, here are the standard private prices per pen. A KwikPen holds four weekly doses, so one pen covers about four weeks.
Prices are correct at the time of writing and taken from the live product page, which takes precedence at ordering. The full range of Mounjaro injection strengths and pricing is worth checking directly, since prices can change. The quoted price is for the medicine: pen needles are bought separately, a sharps bin is needed, and any express review or upgraded delivery may be charged on top. A year is about 13 pens rather than 12, because four weeks is not a calendar month.
Medical Disclaimer
This article is for general information only and is not medical advice, a diagnosis or a recommendation to use any specific medicine. It does not compare the clinical effectiveness of these medicines or suggest that either is preferable. Both are prescription only medicines and should be used under the supervision of an appropriately qualified prescriber. Do not start, stop or change the dose of any medicine based on this article. Suitability depends on an individual clinical assessment, and results can vary between individuals.
Metformin can cause side effects such as nausea, vomiting and diarrhoea, particularly when treatment is started or the dose is changed. Stomach discomfort can also occur. Taking metformin with meals may help reduce some stomach related side effects. If side effects are severe, persistent or concerning, speak to your prescriber or pharmacist.
Lactic acidosis is a rare but serious side effect that requires urgent medical attention. Long term use of metformin can sometimes be associated with vitamin B12 deficiency, so your healthcare professional may consider monitoring your vitamin B12 levels where appropriate. Low blood sugar can also occur in some circumstances, particularly when metformin is taken with other medicines that can lower blood glucose.
Prescription charges, Drug Tariff prices and private prices are correct at the time of writing and can change regularly. Tariff figures are updated over time and concession prices can apply, so confirm current figures with your pharmacy or the NHS Business Services Authority. NHS spending figures are taken from published NHSBSA statistics for the periods stated.
Side effects can be reported through the MHRA Yellow Card scheme. For urgent medical concerns, contact NHS 111, or 999 in an emergency.
