Weight Loss Injections and Crohn's Disease: A UK Guide (October 2026)

01 · The short answer

Can you take weight loss injections if you have Crohn's disease?

It depends on you, not on the diagnosis alone. Mounjaro's label does not list Crohn's by name, but it does flag severe gut or digestive disease as a reason for your prescriber to take extra care, or to recommend against treatment.¹¹³ Crohn's varies enormously, so someone in long remission and someone with active symptoms are very different cases.

Our Crohn's and Mounjaro guide and the complete UK guide to Mounjaro and Crohn's go into more detail.

02 · How we assess

How we assess Crohn's disease in a consultation

You start with a free online consultation, a short health questionnaire with no charge and no obligation. A GPhC-registered prescriber reviews it, not a scoring script. They look at your BMI, medical history and current medicines, and they decide whether Mounjaro is suitable.¹

Tell us everything: your diagnosis, when you were last in a flare, current Crohn's treatments, any surgery, and whether you have trouble keeping weight on. Leaving things out only makes the assessment less safe. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full. You can start your free consultation whenever you are ready.

03 · Do this first

Speak to your IBD team before you order

Your gastroenterologist or IBD nurse knows your disease pattern, which no online form can fully capture. Ask whether a medicine that slows stomach emptying is sensible for you, and what you should do if symptoms change after an injection. Ask also who you should contact first if you cannot tell a flare from a side effect.

Treatment is only for adults who meet the licensed criteria. That means a BMI of 30 or above, or between 27 and 30 with a weight-related condition, used alongside a reduced-calorie diet and more physical activity.¹ If your Crohn's makes a reduced-calorie diet difficult, a dietitian who knows IBD should be part of the plan.

04 · Cost

What it costs if you are approved

The Mounjaro pen at the 2.5mg starting dose has a standard price of £169.99 for a 4-week pen, and all six doses are in stock. Your first 2.5mg pen costs £129.99 with code FIRST40. Every later order is £25 off the standard price (code DOSE25). The consultation is free and the price shown is the price paid.

Delivery is free, next-day and tracked, in temperature-controlled packaging, with same-day dispatch when ordered by 3pm. Needles, a sharps bin and injection guidance come with every order. Payment is by card, Klarna or pay-monthly options, with no subscription.

05 · How Mounjaro affects the gut

How Mounjaro affects the gut

Mounjaro slows how quickly the stomach empties, and that gut effect is the main reason people with digestive conditions need to think carefully. Tirzepatide activates two natural gut-hormone receptors at once, GIP and GLP-1. Together they help regulate appetite, slow stomach emptying and improve the way the body responds to insulin.¹

In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet. That is the intended effect. For someone with a healthy gut it is usually manageable, with mild nausea and altered appetite the commonest early effects that tend to settle.¹³

With Crohn's the question is different. Your bowel already has its own pattern of symptoms, and a medicine that changes how fast food moves through the digestive tract is working in the same area.

It also matters that tirzepatide is not the only injectable of this type. Semaglutide, sold as Wegovy and Ozempic, is a single-action medicine in the same broad family, as it activates GLP-1 only.¹ Ozempic is semaglutide licensed for type 2 diabetes — it is not a UK weight-loss medicine, prescribing it privately for weight loss is off-label, and a regulated UK pharmacy will not supply Ozempic for weight loss. Our page on whether you can take GLP-1 medicines with Crohn's covers the wider class.

The medicine has a half-life of about five days, so after a final dose it takes roughly 4 to 5 weeks to clear the system. There is no way to speed that up, and nothing needs doing while it clears.¹ It is worth knowing before you start, because a side effect that worries you will not disappear the day you stop injecting.

Practically, this means you should think of starting as a considered decision rather than a trial you can instantly reverse.

06 · What the label cautions

What the label cautions about gut disease

Mounjaro is not suitable for everyone, and the cautions that matter most to people with bowel conditions are written into the safety information. You should not take it if you are allergic to tirzepatide or any of its ingredients, and it should not be used during pregnancy or while trying to conceive.¹ Mounjaro must not be used during pregnancy, and it should be stopped at least one month before trying to conceive. If you become pregnant during treatment, stop the medicine and tell your prescriber promptly.

Your prescriber will take extra care, or may recommend against treatment, if you have a history of pancreatitis, severe gut or digestive disease, diabetic retinopathy or gallbladder problems.¹ Whether your Crohn's falls under severe gut or digestive disease is a clinical judgement. That judgement depends on things like how active your disease is, past complications and your current treatment, which is why no website can answer it for you.

Why some symptoms need quick action:

• Severe, persistent stomach pain that may spread to your back, with or without vomiting, could be pancreatitis — stop using Mounjaro and get medical help straight away.
• Pain in the upper right abdomen, fever, or yellowing of the skin or eyes could signal gallbladder problems — get medical help straight away.
• Swelling of the face or throat with difficulty breathing could be a severe allergic reaction — get medical help straight away.

The challenge with Crohn's is overlap. Abdominal pain, nausea and diarrhoea can be part of your disease, a side effect, or something more serious. Agree in advance with your IBD team which symptoms mean you call them, which mean you call 111, and which mean you go to A&E.

If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar, such as shakiness, sweating and confusion. Your prescriber may need to adjust those medicines.¹³ You can report any suspected side effect through the Yellow Card scheme.¹⁹

Our page on taking Mounjaro with Crohn's sets out the same cautions with a focus on the consultation.

07 · Dehydration, kidneys and liver

Dehydration, kidneys and liver

Mounjaro is not known to damage the kidneys or liver directly, but severe vomiting or diarrhoea can cause dehydration, and that can strain the kidneys.¹ For someone with Crohn's, who may already have episodes of diarrhoea, this indirect risk deserves attention.

The label says no dose adjustment is needed for mild to moderate kidney or liver impairment. People with severe impairment need individual prescriber assessment.¹

Keep fluids up, and get medical help straight away if you cannot keep fluids down.¹ That is the label's practical instruction, and it is a good rule to write on the fridge door.

What this looks like day to day:

• Sip fluids steadily through the days after each injection, when early effects are most likely.
• Do not wait for a bad episode to decide who you would call.
• If sickness or diarrhoea continues and you cannot keep fluids down, contact your clinical team — dehydration needs medical help straight away.

Your gastroenterologist, who sees your blood tests and history, is better placed to say whether you are more vulnerable than most.

Blood tests your hospital team already runs for Crohn's, such as kidney and liver function, give your doctors useful context. Mention them in your consultation if you know the results. They help the prescriber decide whether treatment is sensible, and they cost you nothing extra to share.

Treat being unable to keep fluids down as a reason to get medical help straight away, not something to push through.

08 · Weight loss and Crohn's

Weight loss goals when you have Crohn's

Mounjaro is licensed for people who need to lose weight, so it is the wrong tool for anyone already struggling to keep weight on. If your Crohn's has left you underweight or nutritionally low, a weight-reducing medicine is not what you are looking for. The licence is for adults with a BMI of 30 or above, or between 27 and 30 with at least one weight-related condition.¹

Plenty of people with Crohn's do carry extra weight, particularly if steroids, reduced activity or long periods of illness have played a part. For them the question is real. A prescriber will weigh your BMI against your overall health and decide whether the benefit justifies the risk.

On results, the SURMOUNT-1 trial of 2,539 adults found people on tirzepatide alongside diet and exercise lost on average 15% of body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² For someone starting at 100 kg, 20.9% is about 21 kg. These are trial averages, individual results vary, and treatment works alongside a reduced-calorie diet and more activity, not instead of them.

Trial averages do not predict your own result. Treat the numbers as a general picture, not a forecast for you.

Weight loss on Mounjaro is gradual by design. The first weeks on 2.5mg are an adjustment phase and losses are usually modest. Most measurable progress builds from 5mg onward, month by month.¹ If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you.

If your Crohn's means you are losing weight unintentionally, tell your IBD team rather than looking for an injection.

A dietitian experienced in IBD can help you plan a reduced-calorie diet that still protects your nutrition. We would encourage that conversation whatever you decide about medication.

09 · Questions to ask your team

Questions to ask your gastroenterologist and prescriber

Going into the conversation with specific questions makes it far more useful. Here is a list you can take to your IBD team and use again in your online consultation.

• Is my Crohn's currently well controlled, and would a medicine that slows stomach emptying be sensible for me?
• Have I had any complications or surgery that change the risk?
• Which symptoms after an injection should make me call you rather than wait?
• Do any of my current Crohn's treatments change the picture?
• Should I see an IBD dietitian before reducing calories?

Share your full medical history and medicine list during the consultation.¹ That includes over-the-counter products and anything you take for pain or inflammation. A prescriber cannot weigh an interaction they do not know about.

For example, Mounjaro can reduce absorption of oral contraceptives because stomach emptying slows.⁷ The SmPC advises switching to a non-oral method, or adding a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.¹ If absorption is already a concern for you because of your bowel disease, mention it.

A good outcome of this process is not always a yes. If your prescriber says Mounjaro is not right for you, that is the system working as intended. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

Equally, a yes does not end your IBD team's involvement. Our aftercare includes ongoing monthly reviews, dose-titration and follow-up assessments by the prescribing team, plus side-effect support. Repeat orders re-check suitability, with no auto-shipping, so a change in your health can be picked up before the next pen is sent.

If you want a non-injectable discussion as well, our page on orlistat and Crohn's disease support sets out another route to talk about with your clinician. Our full list of weight loss treatments shows what else is on offer.

10 · Dose ladder and a cautious start

Dose ladder and starting cautiously

Everyone starts Mounjaro on 2.5mg once a week, and that starting dose is about letting your body adjust, not about weight loss itself.¹ After at least 4 weeks the dose increases to 5mg. It can then step up by 2.5mg at a minimum of 4-week intervals (7.5mg, 10mg, 12.5mg) up to a maximum of 15mg weekly, depending on how you respond and tolerate it.

Many people settle at 5mg, 10mg or 15mg. Higher is not automatically better, and your prescriber guides the pace.¹ For someone with a sensitive gut, a slower route up the ladder may suit you.

What you should not do is change the dose yourself. Changing doses outside the licence means unknown dosing accuracy and no safety data.¹ If your gut is struggling, speak to your prescriber about holding or stepping down inside the licence.

How the injection works in practice:

• Inject under the skin once a week, on the same day, at any time of day, with or without food.
• Use the stomach area at least 5cm from the belly button, the front of the thigh, or the back of the upper arm if someone else injects.
• Rotate the site with each dose. Each KwikPen holds four weekly doses.

If you miss a dose, take it as soon as you can within 4 days (96 hours) of the scheduled time. If more than 4 days have passed, skip it and take the next one on your normal day, and never take two doses within 3 days of each other.¹ You can change your injection day if at least 3 days have passed since your last dose.

Many people choose a weekend morning so early side effects fall on days off. That can be a sensible choice if you are managing a chronic bowel condition and want a quiet day nearby. Mild nausea, altered appetite and tiredness in the first days after each injection are the commonest early effects and usually settle.¹

If you are looking at other GLP-1 products such as Wegovy tablets, they have their own labels and their own caution lists.

11 · NHS or private route

NHS or private: which route for Crohn's?

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition. The NHS primary-care rollout began in June 2025 with the highest-need groups first, initially BMI 40+ with four or more qualifying conditions.⁴⁶ Full rollout is expected to take years.

If you have Crohn's, your NHS gastroenterology team is already involved in your care, which is a real advantage. Ask them or your GP whether you might qualify and whether they would want to oversee treatment. That route keeps everything in one place, and the NHS guide to tirzepatide explains the basics.⁵

Many people who meet the licensed criteria choose regulated private treatment rather than wait. That is a legitimate choice, but with Crohn's it comes with a responsibility: tell both your NHS team and your private prescriber about each other. Nobody should be making decisions about your gut without the full picture.

What private treatment gives you here:

• A free online consultation reviewed by a GPhC-registered prescriber.
• Genuine KwikPens through official LillyDirect supply, direct from Eli Lilly's UK distribution.
• Ongoing monthly clinical reviews, with repeat orders re-checking suitability.
• Free next-day tracked delivery in discreet, temperature-controlled packaging.

What it does not replace is your hospital team. We are an online pharmacy, and we do not monitor your Crohn's. Our prescribers consider what you tell them and make a judgement on safety for the medicine.

You can confirm that we are a registered pharmacy on the GPhC register (9012878).¹² Be wary of anyone offering to supply without a consultation or prescription. That is a red flag for counterfeit products, and counterfeit pens are a real risk. The MHRA publishes counterfeit alerts and runs the Yellow Card scheme.⁷

Our hub on weight loss injections compares the options in more depth if you are still deciding.

12 · Costs, ordering and storage

Costs, ordering and storing your pens

If you are approved, planning the cost ahead helps you decide calmly. If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £959.96 at standard prices. A new customer's first order is £40 less, and every later order is £25 less. A first year costs £2,711.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,599.88 if you step up through every dose to 15mg, again before discounts.

For other maintenance doses, a 7.5mg pen is £279.99, a 10mg pen is £290.99 and a 12.5mg pen is £319.99 per month. Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £339.00 when checked 11 October 2026.

Ordering takes three steps:

• Complete the free online consultation, a short health questionnaire.
• A GPhC-registered prescriber reviews it. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.
• Your order is dispensed by our registered pharmacy, dispatched the same day if ordered by 3pm, and delivered free next-day. Saturday delivery is £14.99.

You can start from the Mounjaro pen page, and our free companion app, GLPTrackr, helps you log symptoms and doses on iOS and Android. A symptom log is particularly useful if you need to show your IBD team what changed and when.

On storage, keep Mounjaro pens in a fridge at 2 to 8°C and never freeze them. Once in use, a pen can stay out of the fridge not above 30°C for up to 30 days, after which it should be discarded.¹ Keep the cap on to protect it from light. Unopened pens should stay in the fridge until first use and keep until the printed expiry date. If an unopened pen has been out of the fridge, check with the pharmacy before using it.

You can fly with Mounjaro. Carry pens in hand luggage with the prescription label, ideally in a cool bag.¹ Support is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, account chat or phone on 0333 207 0413. For anything urgent about your health, contact your GP, 111 or emergency services rather than waiting for us.

Mounjaro (tirzepatide) is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. Individual results vary. This page is information, not a substitute for medical advice.