Can You Take Mounjaro If You Have Graves' Disease? (October 2026)

01 · The short answer

Can I take Mounjaro if I have Graves' disease?

The honest answer is that it depends on you, and the decision belongs with a clinician who knows your thyroid history.

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes.¹ It is supplied only after a consultation reviewed by a GPhC-registered prescriber, and it is used alongside a reduced-calorie diet and increased physical activity.

That means the first step is never ordering. The first step is disclosure. Graves' disease, any past treatment for it, any thyroid medicine you take and any other thyroid-related history all belong on your health questionnaire. The prescriber can then decide whether treatment is suitable, whether to ask for more information, or whether to decline.

02 · What to decide

The two decisions you are actually facing

The first decision is whether weight-loss treatment is right for you at this point in your thyroid care. If your condition is changing, if your medicines are being adjusted, or if you are newly diagnosed, your specialist may prefer to wait until things settle. That is a clinical judgement we would not want to override.

The second decision is where you get treatment. 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, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions).⁴ Many people who meet the licensed criteria choose regulated private treatment rather than waiting.

03 · Your next step

What to do next

Write down your diagnosis, your current thyroid medicines and the date of your last blood tests. Ask your endocrinologist or GP whether they see a reason you should not use Mounjaro, and whether they want any extra monitoring. Then, if you want to go private, the Mounjaro pen starts at a standard price of £169.99 for the 2.5mg starter pen, and our consultation is free with no obligation. Our broader weight loss clinic page explains how treatment fits around your diet and activity.

04 · What Mounjaro is

What Mounjaro is and what it is licensed for

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly. In the UK it is licensed for weight management in adults and for type 2 diabetes. It comes as a pre-filled multi-dose pen (KwikPen) in six strengths: 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg and 15mg.¹

That description matters for anyone with a thyroid condition, because it tells you what the medicine was developed and licensed to do. It is a weight-management and type 2 diabetes treatment. It is not a thyroid treatment, and it is not intended to alter your thyroid condition. Your thyroid medicines, whether you take tablets, have had treatment in the past, or are under hospital follow-up, stay under the control of your endocrinology team.

Because the pen comes in six strengths, treatment is stepped. If you are managing a condition such as Graves' disease, that stepped approach gives you natural points to check how you feel and to speak to your clinician before moving up.

Mounjaro is a prescription-only medicine. It is supplied only after an online consultation reviewed by a GPhC-registered prescriber, and it is used alongside a reduced-calorie diet and increased physical activity. Individual results vary. This page is information, not a substitute for medical advice.¹³

We recommend that anyone with a long-term condition reads the leaflet sections on who should not use the medicine and what to tell your doctor before starting. If anything in them might apply to you, take the leaflet to your appointment and ask directly.

The practical point is simple. Knowing what a medicine is licensed for helps you frame your question. Instead of asking whether Mounjaro is safe with Graves' disease in general, ask your endocrinologist whether they see any reason in your own history, current treatment or recent results that would make weight-management treatment unsuitable, or that would call for closer follow-up while you use it.

05 · How it works

How Mounjaro works, and why people ask about the thyroid

Tirzepatide is the first treatment of its kind to activate two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties, and improve the way the body responds to insulin. In practice, most people feel fuller sooner and less hungry between meals, which supports a reduced-calorie diet.¹

Nothing in that description says the medicine acts on the thyroid gland. Its action is on gut-hormone receptors, appetite and stomach emptying. In rodent studies tirzepatide caused thyroid C-cell tumours; it is not known whether this applies to humans, and no increase has been shown in human trials. As a precaution, tell your prescriber if you or a close relative have had medullary thyroid cancer or the inherited condition MEN 2 — they will weigh this in your assessment. Routine thyroid monitoring is not required for most people. People still ask about the thyroid for understandable reasons. Thyroid conditions can affect weight, appetite, energy and heart rate, and changes in weight can sometimes prompt a review of thyroid medicine doses. Those are real everyday considerations, and they are why your endocrinologist should know if you start a weight-management medicine.

If you notice new symptoms after starting, tell your prescriber and your specialist, and report them through the Yellow Card scheme.¹⁹

Slower stomach emptying has one practical implication worth knowing about if you take tablets of any kind. Slowing how quickly the stomach empties is the reason the medicine can reduce absorption of oral contraceptives, according to MHRA guidance.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 What you should do is mention every medicine you take, including thyroid medicines, so the prescriber can consider the whole picture and tell you if anything needs timing or review.

06 · Weight and Graves'

Weight and Graves' disease: what to expect from treatment

Weight changes are common around thyroid conditions. The first thing to say is that weight change linked to an overactive or recently treated thyroid is something your endocrinology team will want to understand. If your weight is shifting without explanation, that is a conversation for your clinician before any weight-loss medicine is considered.

Where weight management is appropriate, the headline trial evidence for tirzepatide comes from SURMOUNT-1. In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their 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 These are trial averages, and individual results vary. Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.

Trial averages do not predict your own result. What they do show is the scale of what the medicine can do when used as licensed with lifestyle changes.

For a worked example only: for someone starting at 100 kg, 20.9% is about 21 kg. That is straight arithmetic of the trial average, not a forecast for you, and it says nothing about how quickly any weight would come off.

If you have Graves' disease, sensible weight management usually runs on several tracks at once. Your thyroid care stays with your specialist. Food and activity changes are the foundation. If medicine is appropriate, it is added with prescriber oversight and with your specialist aware of it. Nutrition and lifestyle support matters just as much as the injection, and our prescribing team can talk through eating habits and activity during your reviews.

Be cautious of anyone who promises a specific outcome. Results vary, and no website can say in advance how your body will respond when you have a condition that itself affects metabolism.

07 · Who should not use it

Who cannot take Mounjaro, and when should you not inject?

Mounjaro is not suitable for everyone. 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. 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. Always share your full medical history and medicine list during consultation.¹¹³ 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 consultation asks about your medical history, current medicines and your reasons for wanting treatment. A GPhC-registered prescriber reviews it, not a scoring script. Payment is taken when you place the order; if the prescriber decides the treatment is not suitable, the order is refunded automatically in full.

On the question of when not to inject, the safe answer is to follow the pen's instructions and your prescriber's advice. If you feel unwell, if you have questions about a dose, or if something in your health has changed since your last review, contact the prescribing team before your next injection rather than deciding alone. Our support team is available Monday to Friday, 9am to 5pm, by email at support@everydaymeds.co.uk, through the account portal chat, or by phone on 0333 207 0413.

For someone with Graves' disease, a change in thyroid status, a new thyroid medicine or a change in dose is exactly the sort of development to share with both your specialist and your prescriber. It does not mean treatment must stop. It means the people responsible for your care should know, so they can decide together.

Repeat orders re-check suitability, and there is no auto-shipping. That design is deliberate: your circumstances can change between pens, and each order is a chance to flag it. Ongoing monthly reviews, dose titration and follow-up assessments by the prescribing team are part of the service, along with side-effect support.

If you are unsure whether you should use the pen on a given week, do not guess. Pause, read the leaflet, and ask.

08 · NHS and private

NHS or private treatment when you have Graves' disease

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, and the NHS primary-care rollout began in June 2025 with the highest-need groups first (initially BMI 40+ with four or more qualifying conditions). Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.⁴⁶

Whether you qualify depends on your BMI, your other conditions and local arrangements, so your GP is the right person to confirm. The NHS guide to tirzepatide also explains the medicine in plain terms.⁵

One advantage of the NHS route for someone with Graves' disease is continuity. If your GP and endocrinology team are already involved, weight-management treatment can be considered alongside your thyroid care in one joined-up conversation. If you go private, the practical step is to make that joined-up conversation happen yourself: tell your GP or specialist you are considering treatment, and share what your prescriber advises.

Private treatment suits people who meet the licensed criteria but do not want to wait for NHS access. With us, the consultation is free and carries no obligation. The price shown is the price paid, with no hidden fees. A new customer can use code FIRST40 for £40 off a first order at any dose, and an automatic £25 reorder discount applies to every future order (code DOSE25).

Our supply comes through official LillyDirect, meaning Mounjaro direct from Eli Lilly's UK distribution, with genuine KwikPens, and all six doses are in stock. Delivery is free, next-day, tracked and temperature-controlled, and same-day dispatch applies when you order by 3pm.

Neither route is better in every case. The better route is the one that gets you appropriate, supervised treatment with your thyroid care kept in view.

09 · Other medicines

Ozempic, Wegovy and other options with Graves' disease

People often ask whether a different injection would be safer than Mounjaro if they have Graves' disease. Semaglutide, sold as Wegovy and Ozempic, acts on one receptor, whereas tirzepatide activates two gut-hormone receptors. Ozempic is licensed for type 2 diabetes only; it is not a UK weight-loss medicine. That is a difference in mechanism, not a statement that one is safer for your thyroid.¹

Wegovy pens come in 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg strengths, once weekly, stepping up after at least four weeks to the 2.4mg maintenance dose from week 17.¹⁸ Liraglutide (Saxenda, and products such as Erly) is supplied at 6mg per millilitre and is a daily injection, unlike once-weekly Mounjaro and Wegovy.

Whether any of them suit you with Graves' disease is for your prescriber and specialist. Our page on whether you can take these medicines with Graves' disease sets out the same cautious position for the wider group.

A fair way to compare is to ask three questions of each option. Is it licensed for weight management in adults? What does the product information say about people with my conditions? Can my specialist and prescriber monitor me while I use it? If the answer to the last question is yes and the clinicians are comfortable, the practical differences, such as schedule and price, matter more.

On price, Mounjaro standard prices start at £169.99 for the 2.5mg pen, checked 10 October 2026. Across the UK pharmacies we track, the cheapest and dearest Mounjaro pens at any dose run from £143.96 to £339.00, checked 10 October 2026.

For tablets, see current Wegovy tablet prices on the product page. No trial has compared Mounjaro directly with either tablet, so results from separate trials should not be set against each other as if they were head to head.

10 · Related conditions

Other long-term conditions and Mounjaro

Graves' disease is one of several long-term conditions that people ask about before starting Mounjaro.

If you have an autoimmune condition, you may also be wondering how treatment fits with your wider care. Our guide on whether you can use Mounjaro with lupus follows the same approach. For gut conditions, see the page on Crohn's disease. For people with reduced kidney function, the guide on kidney disease explains what to raise with your prescriber, and the guide to endometriosis covers another frequent question. If you have had your gallbladder removed, see our no-gallbladder guide.

Having more than one condition does not automatically rule treatment out, and it does not automatically make it fine. It does make your consultation answers more important. List every diagnosis, every medicine and every specialist involved. The more complete your picture, the better your prescriber can judge suitability.

It also helps to keep one person informed of everything. Your GP often holds the overall record, and asking them to note that you are considering or using weight-management treatment can prevent mixed messages between specialists. If you have several hospital teams, send each of them a short note.

Finally, treat the first few weeks with extra attention. Starting any new medicine on top of existing conditions is the moment when new symptoms are most likely to be noticed and most useful to report. Keep a simple note of how you feel, and share it at your monthly review.

11 · Safety and storage

Safety, storage and reporting side effects

Safe use starts with buying from a regulated source. Mounjaro is a prescription-only medicine, and anyone offering to supply it without a consultation or prescription is a warning sign. You can check our registration on the GPhC public register under number 9012878, and the MHRA publishes counterfeit medicine alerts.⁷¹²

For storage, keep unopened pens in the fridge between 2–8°C until first use, and they keep until the printed expiry date. Once in use, a pen can be kept out of the fridge at a temperature not above 30°C for up to 30 days after first use, and must then be thrown away. Do not use a pen that has been above 30°C or has been frozen.¹³ For anything outside that, such as an unopened pen left out, check the patient information leaflet and contact the pharmacy rather than guessing.

If you have a thyroid condition, side effects deserve particular attention because symptoms can overlap. A new symptom might be a medicine effect, a thyroid change, or unrelated. You cannot tell which on your own, and nor can a website. Tell your prescriber, tell your specialist, and report suspected side effects through the MHRA Yellow Card scheme.¹⁹

If you ever stop, tirzepatide has a half-life of about five days, so after a final dose it takes roughly four to five weeks to clear the system. There is no way to speed this up, and nothing needs doing while it clears.¹

Needles, a sharps bin and injection guidance are included with every order. Follow the pen's instructions for each injection.

Finally, a note on tracking. Our free GLPTrackr companion app, available on iOS and Android, helps you log doses and how you feel, which can make appointments with your specialist more productive.

12 · Serious side effects

Serious side effects: when to get help straight away

Serious side effects are uncommon but need urgent attention. Seek immediate medical help for: severe, persistent stomach pain that may spread to your back, with or without vomiting (possible pancreatitis); pain in the upper right abdomen, fever or yellowing of skin/eyes (possible gallbladder problems); or signs of a severe allergic reaction such as swelling of the face or throat and difficulty breathing. If you take insulin or a sulfonylurea alongside Mounjaro, watch for low blood sugar (shakiness, sweating, confusion) — your prescriber may need to adjust those medicines.¹