Check the doctor.uk BMI treatment threshold
We take into account your weight history, not just your current weight.
The medicine
We mainly prescribe tirzepatide (Mounjaro), a once-weekly injection licensed for weight management alongside diet and activity.
It reduces appetite. Most people feel full sooner and think about food less.
Your doctor may prescribe another licensed medicine if it suits you better.
The standard schedule
- Start at 2.5mg for four weeks
- Increase by 2.5mg, no sooner than every four weeks
- Stay on the lowest dose that works for you
- Your doctor reviews you at each step
Standard or tailored
Standard
The licensed schedule tested in the trials. Most people start and stay here.
Tailored
A different dose, interval or preparation, when your doctor has a clinical reason. Off-label, with closer review. How tailored plans work.
Your doctor decides which suits you, after your consultation.
Side effects
Stomach and bowel effects are the most common. They are usually mild to moderate and settle as your body adjusts.
| Event | 5mg | 10mg | 15mg |
|---|---|---|---|
| Nausea | 24.6% | 33.3% | 31.0% |
| Diarrhoea | 18.7% | 21.2% | 23.0% |
| Vomiting | 8.3% | 10.7% | 12.2% |
| Constipation | 16.8% | 17.1% | 11.7% |
Jastreboff et al., New England Journal of Medicine, 2022. Full context on The evidence.
Tell us early
Most side effects happen during the step-up. Your doctor can slow the pace, lower the dose, or prescribe for nausea, constipation or reflux.
Serious side effects
Pancreatitis and gallbladder problems are uncommon. Your doctor explains the warning signs and what to do.
Who can have treatment
You may be eligible if
- You’re 18 or over and live in the UK
- Your BMI is 30 or more, or 27 or more with a weight-related condition
- Your BMI is above 20 now, but has been higher in the last three years
- You can attend reviews and report side effects
It isn’t suitable if
- You’re pregnant, breastfeeding or trying to conceive
- You or your family have had medullary thyroid cancer or MEN2
- You’ve had pancreatitis or an eating disorder
- Some other medicines or conditions apply. Your doctor will check
Your doctor makes the final decision at your consultation.
Four licensed medicines
Your doctor recommends one after talking with you.
| Mounjaro Weekly injection |
Wegovy injection Weekly injection |
Wegovy tablets Daily tablet |
Foundayo Daily tablet |
|
|---|---|---|---|---|
| Price from, per 4 weekly cycle | £109 | £132 | £119 | £119 |
| Active ingredient | Tirzepatide | Semaglutide | Semaglutide | Orforglipron |
| Format | Injection | Injection | Tablet | Tablet |
| How often | Once a week | Once a week | Once a day | Once a day |
| Needles | Yes | Yes | No | No |
| Timing restrictions | None. Any time, with or without food. | None. Any time, with or without food. | Yes. On an empty stomach with a little water, then nothing for 30 minutes. | None. Any time, with or without food. |
| Average weight lost in the main trial | 20.9% over 72 weeksSURMOUNT-1, 15mg, n=2,539 | 14.9% over 68 weeksSTEP-1, 2.4mg, n=1,961 | 13.6% over 64 weeksOASIS-4, 25mg, n=307 | 11.2% over 72 weeksATTAIN-1, 36mg, n=3,127 |
| Storage | Refrigerated | Refrigerated | Room temperature | Room temperature |
| Common side effects | Nausea, vomiting, diarrhoea, constipation | Nausea, vomiting, diarrhoea, constipation | Nausea, vomiting, diarrhoea, constipation | Nausea, vomiting, diarrhoea, constipation |
| Available as a tailored plan | Yes, at 2.5mg, 5mg and 7.5mg | No | No | No |
More on the evidence, pricing and switching medicines.
See if treatment suits you.
Start with a one-minute eligibility check.