Mysimba vs Mounjaro: Tablet or Injection? (October 2026)

01 · The verdict

Mysimba vs Mounjaro: who each option suits

Mounjaro suits adults who are comfortable with a weekly injection and meet the licensed criteria after prescriber review. Mysimba suits people who would rather take a tablet each day and for whom a prescriber judges it appropriate.

Mounjaro is licensed in the UK for weight management in adults. It comes as a pre-filled KwikPen in six strengths from 2.5mg to 15mg.¹

Neither option is a shortcut. Treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.² If you want a wider look at tablets, see our guide to the appetite suppressant Mysimba, or our broader which treatment is right for you page.

02 · Side by side

Mysimba and Mounjaro compared

03 · How to choose

Decision factors that matter

The first factor is how you feel about injections. If a weekly injection is a deal-breaker, a tablet may be the only route you will stick with. Many people find the weekly pen easier than a daily routine, since you only need to remember one day.

The second factor is the strength of evidence you want. SURMOUNT-1 enrolled 2,539 adults, and at 72 weeks 85% of those on 5mg, 89% on 10mg and 91% on 15mg had lost at least 5% of body weight.²

The third factor is your health history. Other medicines, existing conditions and previous reactions all shape what is suitable. Our free consultation is reviewed by a GPhC-registered prescriber, and unsuitable orders are refunded automatically.

The fourth factor is cost over time. Mounjaro is priced per dose strength, so your monthly cost depends on where you settle. A first year costs £2,399.88 if you stay on 5mg after your 2.5mg starting pen, up to £3,279.88 if you step up through every dose to 15mg, at standard prices before discounts. A new customer's first order is £40 less, and every later order is £25 less.

04 · Rule of thumb

A quick way to decide

• Mounjaro may suit you if you accept a weekly pen and meet the licensed criteria after prescriber review.
• Consider Mysimba if you strongly prefer a daily tablet and a prescriber confirms it is appropriate for you.
• Choose neither on your own if you are pregnant, planning pregnancy, or taking medicines that may interact. Speak to a prescriber first.

05 · How each works

How Mysimba and Mounjaro work

Mounjaro contains tirzepatide, which activates two natural gut-hormone receptors at once: GIP and GLP-1. Together these help regulate appetite, slow how quickly the stomach empties and improve how 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 dual action distinguishes Mounjaro from single-action GLP-1 medicines such as semaglutide, the active ingredient in Wegovy and Ozempic.¹ Tirzepatide has a half-life of about five days. After a final dose it takes roughly 4 to 5 weeks to clear the system, and nothing needs doing while it does.¹

Mysimba is a different medicine in a different form: a daily tablet. Mysimba is not a once-weekly injection and does not have Mounjaro's dual-receptor action.

If you are weighing up other tablets and stimulant-type options, our comparison of Duromine against Mounjaro covers a similar question for a different medicine.

06 · Mounjaro trial evidence

What the Mounjaro trials show

In SURMOUNT-1, 2,539 adults taking 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. The comparison group on lifestyle changes alone lost 3.1%.² These are trial averages and individual results vary.

To make that concrete, for someone starting at 100 kg, 20.9% is about 21 kg. Your own starting weight, dose and response will differ, and trial averages do not predict your own result.

The spread of outcomes matters too. At 72 weeks, half of participants on 10mg and 57% on 15mg lost at least 20% of their body weight.²

SURMOUNT-5 is the first large head-to-head trial of tirzepatide against semaglutide 2.4mg (Wegovy). Over 72 weeks, among 751 adults, those on tirzepatide lost on average 20.2% of body weight versus 13.7% on semaglutide, and average loss was 22.8 kg versus 15.0 kg.¹⁵ That trial supports a direct tirzepatide-versus-Wegovy comparison.

07 · Mounjaro vs Wegovy

Where Wegovy fits in

Wegovy is semaglutide 2.4mg, a once-weekly injection. Its pens run 0.25mg, 0.5mg, 1mg, 1.7mg and 2.4mg, stepping up after at least 4 weeks to reach the 2.4mg maintenance dose from week 17.¹⁸

In the STEP 1 trial, adults on semaglutide 2.4mg lost on average 14.9% of body weight over 68 weeks, compared with 2.4% on placebo.⁹ In STEP 1, gastrointestinal side effects were reported by 74.2% of people on semaglutide versus 47.9% on placebo, and 7.0% stopped treatment because of side effects, compared with 3.1% on placebo.⁹

Both are effective, licensed treatments. Which suits you depends on your health profile, tolerance and prescriber advice, not the headline number alone.¹⁵ You can see how the pen strengths line up in our Wegovy strength against Mounjaro guide, or view the Wegovy pen directly.

08 · NHS and private access

NHS and private access

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, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting. If you are on a waiting list, ask your GP what stage your area has reached.

The same applies to Wegovy: NHS access runs through specialist weight-management services, so ask your GP.

09 · Switching and combining

Switching, stacking and combining

Never start Mounjaro on top of another weight-loss medicine without prescriber approval. Mounjaro must not be combined with other GLP-1 medicines, unlicensed "research" peptides such as retatrutide (which has no UK licence), or compounded copies. These combinations have no safety data and no regulated supply chain. If something promises faster results outside a licensed pathway, that is the warning sign.

If you are moving from semaglutide, there is no licensed direct conversion to tirzepatide. Switching is done under prescriber supervision: typically the previous medicine is stopped, a washout interval is observed and Mounjaro starts at a dose your prescriber judges appropriate, often 2.5mg. Never run two GLP-1 medicines together.

For a tablet such as Mysimba, whether it can sit alongside or before an injection is a prescriber decision. Our page on taking Mysimba and orlistat together explains why combining weight-loss medicines should always be reviewed first. Tell the prescriber about every medicine and supplement you take.

10 · Tablets and other options

Tablets, supplements and other options

There is no tablet form of Mounjaro: tirzepatide is injection-only in the UK. Two GLP-1 weight-loss tablets are now licensed: Wegovy tablets (oral semaglutide, Novo Nordisk), approved by the MHRA in June 2026, and Foundayo (orforglipron, Eli Lilly), approved in August 2026.²⁰²¹ They are different medicines from Mounjaro, with their own dosing, eligibility checks and trial results, and both are prescription-only.

For current Wegovy tablet details, see our all weight loss treatments hub.

Orlistat (a tablet) blocks some dietary fat absorption and produces smaller average losses. Wegovy and Saxenda (liraglutide) are other licensed injectables; liraglutide is a daily injection, unlike once-weekly Mounjaro and Wegovy. "Natural GLP-1" supplements such as berberine are not medicines, are not regulated for this use and have no comparable trial evidence. They are available cheaply without assessment, and that low cost is a reason for caution, not a recommendation.

11 · Safety and side effects

Safety, side effects and who should not take either

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. Read the leaflet in full before starting anything.

Regulators have looked specifically at whether GLP-1 medicines are linked to low mood or suicidal thoughts: the EMA's safety committee reviewed the evidence and concluded in 2024 that it does not support a causal link, and the MHRA keeps this under continuous review. Tell your prescriber about any history of depression, and seek help promptly if your mood drops or you have distressing thoughts during treatment.¹⁷

If you have thoughts of harming yourself or ending your life, get help straight away. Call 999 or go to A&E if you are in immediate danger. In England you can call NHS 111 and choose the mental health option, any time. You can also call Samaritans free on 116 123, day or night. Tell your prescriber about any change in your mood while taking Mounjaro.

If you notice a new symptom on any medicine, speak to your prescriber and report it through the MHRA Yellow Card scheme.¹⁹ Also be wary of counterfeit products: only buy from a pharmacy listed on the GPhC register. Ours is registered under number 9012878, and you can verify it on the GPhC register.¹² 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. Mounjaro slows stomach emptying, which can reduce how well oral contraceptive pills are absorbed. Switch to a non-oral method, or add a barrier method (such as condoms), for 4 weeks after starting Mounjaro and for 4 weeks after each dose increase.

Mounjaro is a prescription-only medicine, supplied only after an online consultation reviewed by a GPhC-registered prescriber. 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.

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

13 · Cost and ordering

What Mounjaro costs and how ordering works

The Mounjaro pen is priced by strength, and all six doses are in stock. The standard price of the 2.5mg pen is £169.99 per month, 5mg is £189.99, 7.5mg is £244.99, 10mg is £274.99, 12.5mg is £289.99 and 15mg is £299.99. Your first 2.5mg pen costs £129.99 with code FIRST40. Switching to us at 15mg? Your first order is £259.99. An automatic £25 reorder discount applies to every future order (code DOSE25).

If you step up after 4 weeks on each dose, your first four pens (2.5mg to 10mg) cost £879.96 at standard prices, before discounts. Across the UK pharmacies we track, Mounjaro pens ranged from £143.96 to £319.99 per month as of 25 October 2026, so it is worth comparing like for like. Our Mysimba or Mounjaro from a UK registered pharmacy page covers what to check before you buy.

Ordering takes three steps:

• Free online consultation. A short health questionnaire, with no charge and no obligation. Start your free consultation.
• Prescriber review. 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.
• Dispatch and delivery. Same-day dispatch when ordered by 3pm, with free next-day tracked delivery in discreet, temperature-controlled packaging. Saturday delivery is £14.99.

Our Mounjaro is official LillyDirect supply, sourced directly from Eli Lilly's UK distribution as genuine KwikPens. Ongoing monthly reviews are included, and you can pay with Klarna or pay-monthly options with no subscription lock-in.