Weight loss injections: who is eligible, NHS or private?

A friend has started a weekly pen, or a website has offered you one after a short online form. Then you read that the NHS offers the same injection, and you wonder whether you qualify, and what the difference is.

The short answer: NHS access is real but tightly limited for now. It depends on your BMI and how many weight-related conditions you have. Privately, a doctor can consider you from a lower BMI, but only after seeing you in person. At Medical Express Clinic the medicine usually discussed is Mounjaro (tirzepatide). A GMC-registered doctor examines you, reviews your blood tests and body composition scan, and then decides with you whether it suits you.

If you would rather skip the reading, you can book a weight loss assessment at 117a Harley Street, Monday to Friday. The package is £650, and you can call 0207 499 1991 with any questions first.

Can you get weight loss injections on the NHS?

Yes, if you meet the criteria, though most people who ask don't yet. NICE technology appraisal TA1026 recommends tirzepatide on the NHS for adults with a BMI of at least 35 and at least one weight-related condition, alongside a reduced-calorie diet and more activity. Because so many people would qualify, NHS England is rolling it out in phases, starting with the people at highest risk.

The phases are set by BMI and by how many of five qualifying conditions you have: type 2 diabetes, high blood pressure, high cholesterol (dyslipidaemia), obstructive sleep apnoea and cardiovascular disease.

NHS England phased rollout of tirzepatide in primary care (interim commissioning guidance for NICE TA1026)

For people from South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean backgrounds, the NHS usually lowers each BMI threshold by 2.5, because weight-related illness starts at a lower BMI in these groups. If you think you fit one of these rows, ask your GP about a referral. NICE guideline NG246 sets out how the NHS assesses and manages overweight and obesity more widely.

NHS or private: how do they compare?

NHS and private weight loss injections side by side

Neither is the "right" choice for everyone. If you qualify on the NHS and are happy to wait, that is a good option. If you sit outside the current NHS groups, or want a named doctor following you closely from the first week, a private assessment may suit you better.

Who may be considered privately?

We may consider adults when body mass index is 30 or above, or 27 or above with a weight-related condition such as type 2 diabetes, high blood pressure or high cholesterol. Those figures follow the licensed UK indication for weight management.

BMI is a useful first screen, but it is only one number. Your doctor also looks at your history, the examination, your blood results, your current medicines, and whether you can attend the planned reviews. Meeting a BMI figure opens the conversation; the decision comes after all of that.

Why does a doctor need to see you in person?

Because a form can't weigh you, examine you, take blood, or check that the numbers typed in match the person in the room. Most weight loss injections in the UK are now sold through an online questionnaire. The medicine is the same, but the safety net is different.

The General Pharmaceutical Council, which regulates pharmacies in Great Britain, says weight-management medicines should not be prescribed from an online questionnaire alone. It expects the prescriber to verify weight, height and BMI independently. An examination and baseline bloods pick out the people for whom the medicine would be unsafe, and regular reviews let the dose be adjusted safely. Our guide to GLP-1 overdose risk explains what can go wrong without that supervision.

What happens at the first visit, and what does it cost?

Allow about 45 minutes. The doctor takes a history, examines you, measures your height and weight in the clinic, and reviews your current medicines. The included baseline blood panel covers full blood count, kidney function, liver function, lipids and HbA1c. Sometimes those results point to something that needs attention first, such as diabetes risk, liver strain or a lipid pattern that changes the decision.

The body composition scan measures fat, including visceral fat, and muscle. That gives you a real starting point, so later reviews can show how your body has changed beyond the number on the scales.

The package is £650. It covers the consultation and examination, the blood panel, the body composition scan, four follow-up reviews with the same doctor at weeks 4, 8, 12 and 16, and direct access to your doctor in between. If a prescription is issued, you buy the pens separately at a pharmacy, from about £200 per pen. Full details are on the weight loss injections page.

A prescription is issued only when the doctor has seen you, reviewed all of this, and decided the medicine is appropriate. It is never guaranteed, and deciding not to start is a valid outcome too.

How much weight do people lose?

The main weight-management trial, SURMOUNT-1, followed 2,539 adults without diabetes for 72 weeks. Everyone also had diet and activity support. Average weight loss was 15% on the 5 mg dose, 19.5% on 10 mg and 20.9% on 15 mg, compared with 3.1% on placebo. For someone starting at 100 kg, the top-dose average is roughly 21 kg.

Those are averages across a trial population. They can't tell your doctor how much you will lose. Some people lose more, some much less, and a few stop because of side effects. Your response depends on your starting weight, how well you tolerate the dose, your other conditions, and what you can sustain with food, sleep and activity. That is what the four reviews are for.

Health conditions to mention at your first visit

Being open about your health is what keeps treatment safe, so bring these up even if they feel minor:

• Type 1 diabetes, which sits outside the weight-management licence. Your doctor will talk you through other options.
• Pregnancy, trying to conceive or breastfeeding. The MHRA advised in 2025 that these medicines should not be used at those times, and licensed information says tirzepatide should be stopped at least one month before trying to conceive.
• The contraceptive pill. Tirzepatide can make it less reliable, so the MHRA advises a non-oral method, or adding condoms, for 4 weeks after starting and for 4 weeks after each dose increase.
• Any pancreatic disease, gallbladder trouble, or a severe gut problem such as gastroparesis.
• Any heart, kidney, liver or thyroid condition, and any known allergy to the ingredients.

Each is reviewed individually. If you are acutely unwell, with new, severe or rapidly worsening symptoms, you need a same-day GP or emergency assessment first.

What happens if treatment starts?

Your appointments at a glance

The usual licensed approach is to begin at a low weekly dose and increase it gradually if you tolerate it, and your doctor sets that schedule. At each review you get diet and lifestyle support, a check on side effects, and a decision on whether to adjust the dose, continue or stop. How long you stay on treatment is a clinical decision made together, not a fixed course.

Which side effects should you watch for?

Nausea, vomiting, diarrhoea, constipation and abdominal pain are common, and they often ease after the early weeks. If they persist, or make it hard to eat and drink, contact your doctor so the dose can be changed. Gut side effects can lead to dehydration, which can strain the kidneys.

Seek urgent medical help for severe, persistent abdominal pain. Licensed information warns about pancreatitis and advises stopping the medicine and getting help if that pain appears.

If you have diabetes and also take insulin or a sulphonylurea, the injection can bring on low blood sugar, so bring your current doses to the first visit. The medicine also slows how quickly the stomach empties, which can change how some tablets are absorbed. List everything you take, including inhalers, contraceptives and anything bought without a prescription.

If you have questions before booking, contact the clinic on 0207 499 1991. You might also find our guide on when to see a private GP useful.