Mounjaro vs Oral GLP-1 Tablets

Mounjaro (tirzepatide) is a weekly injection, while the GLP-1 tablets licensed for weight management in the UK, Wegovy tablets (oral semaglutide) and Foundayo (orforglipron), are taken once a day. In separate trials, Mounjaro produced the largest average weight loss, the 25mg Wegovy tablet came next, and orforglipron produced somewhat less. Tablets avoid needles, and Foundayo has no food rules, but they do not avoid the gastrointestinal side effects. A trial has also looked at switching from tirzepatide to orforglipron to maintain weight loss. This guide sets out the evidence so you can discuss the options with a prescriber.

The options being compared

Mounjaro (tirzepatide)

Mounjaro, made by Eli Lilly, is a once-weekly injection given using a multi-dose KwikPen. It was authorised by the MHRA for weight management in 2023 and recommended by NICE in TA1026, with a phased NHS rollout that began in June 2025. Tirzepatide activates both GIP and GLP-1 receptors. See our complete guide to Mounjaro and the Mounjaro hub.

Wegovy tablets (oral semaglutide)

Wegovy tablets, made by Novo Nordisk, contain semaglutide, the same molecule as Wegovy injections, combined with an absorption enhancer. They were authorised by the MHRA for weight management in June 2026. The dose rises from 1.5mg daily through 4mg and 9mg to 25mg, with at least a month at each step. See our oral semaglutide guide.

Foundayo (orforglipron)

Foundayo, also made by Eli Lilly, is a small-molecule GLP-1 receptor agonist, not a peptide. It was authorised by the MHRA in August 2026 for weight management and for type 2 diabetes, making the UK the first country in Europe to approve it. It can be taken at any time of day, with or without food. See our Foundayo guide.

What about Rybelsus?

Rybelsus is also oral semaglutide but is licensed only for type 2 diabetes, at lower doses. It is not a weight-management medicine. See Rybelsus and weight loss.

At a glance

Regulatory details change, so check the MHRA and the current Summary of Product Characteristics (SmPC) for each medicine.

How they work

All three reduce appetite by activating GLP-1 receptors in the brain and slowing stomach emptying. The differences lie in additional receptor activity and how the medicine gets into the body.

Tirzepatide also activates GIP receptors. GIP is another gut hormone, and combining it with GLP-1 appears to increase the effect on appetite and weight. This is thought to be one reason tirzepatide produced more weight loss than semaglutide in the SURMOUNT-5 head-to-head trial. Read more in how Mounjaro works.

Oral semaglutide is a peptide that would normally be broken down in the stomach. An absorption enhancer called SNAC allows a small fraction to be absorbed through the stomach lining, which is why the tablet must be taken on an empty stomach.

Orforglipron is a small molecule that activates the GLP-1 receptor. It is absorbed like a conventional tablet, so food does not interfere in the same way.

What the trials show

Placebo-controlled trials

Points to bear in mind:

• Separate trials. These figures come from different trials in different populations. There is no head-to-head trial of Mounjaro against either tablet for weight management at the time of writing.
• Different estimates. Some results are reported in two ways: including everyone who started (lower figure) or estimating the effect in people who took the medicine as directed (higher figure).
• Dose labelling. The orforglipron doses studied in ATTAIN-1 were labelled differently from the strengths marketed as Foundayo. The SmPC and your prescriber are the authority on how they relate.
• Wide variation. In every trial, some people lost much more than the average and some much less. See realistic weight loss expectations.

ATTAIN-MAINTAIN: switching from Mounjaro to a tablet

ATTAIN-MAINTAIN is particularly relevant to people on Mounjaro. It enrolled people who had lost weight on tirzepatide or semaglutide injections in the SURMOUNT-5 trial and whose weight had levelled off. They were randomly assigned to switch to orforglipron or to placebo for 52 weeks. According to topline results announced by Eli Lilly in December 2025:

People who switched from tirzepatide to orforglipron regained some weight on average, around 5kg, but much less than those who switched to placebo. This suggests orforglipron may help maintain a substantial part of the weight lost on Mounjaro, although not all of it. Full peer-reviewed results provide more detail, and this does not mean switching is right for everyone.

For context, the SURMOUNT-4 trial (JAMA, 2024) showed that people who stopped tirzepatide and switched to placebo regained a significant proportion of their weight, while those who continued tirzepatide maintained or increased their weight loss. See weight regain after stopping GLP-1 medication.

Side effects compared

All three medicines share the same main side effects because all act on GLP-1 receptors.

Frequencies here are approximate and based on trial reports and SmPCs at the time of writing; check the current SmPC for each medicine.

In OASIS 4, nausea affected just under half of participants on oral semaglutide 25mg and vomiting around three in ten. In ATTAIN-1, gastrointestinal side effects were the most common reason people stopped orforglipron, and they increased with dose. In SURMOUNT-1, gastrointestinal side effects were also the most common with tirzepatide, mostly mild to moderate and concentrated during dose escalation. See oral GLP-1 side effects and Mounjaro side effects.

A note on contraception

The MHRA has advised that people taking GLP-1 medicines who could become pregnant should use effective contraception. For tirzepatide specifically, it has noted that the medicine may reduce the effectiveness of oral contraceptives in some people, particularly around the start of treatment and after dose increases, so a non-oral method or additional barrier method may be advised. Check the SmPC for each tablet and speak to a pharmacist.

Daily life compared

Routine

• Mounjaro: one injection on the same day each week. If a dose is missed, the SmPC sets out a window in which it can still be taken.
• Wegovy tablets: one tablet every morning on an empty stomach, swallowed with a small sip of water, then a wait (usually at least 30 minutes) before eating, drinking or taking other medicines.
• Foundayo: one tablet a day, at any time, with or without food.

Storage and travel

Mounjaro pens must be kept in the fridge before first use and within temperature limits afterwards; see storing and travelling with Mounjaro. Tablets are generally stored at room temperature, which makes travel simpler. Check the patient leaflet for your product.

Needles

For people with a fear of needles, a tablet removes the main barrier to treatment. Mounjaro pens use a fine needle, and most people find injecting becomes routine, but this is a genuine consideration for some. See how to use the Mounjaro KwikPen.

Adherence

Weekly treatments are often easier to take consistently than daily ones, but a person who dislikes injecting may find a daily tablet more sustainable. The question to consider is which you would keep taking reliably over a year or more.

Who might each suit?

These are general considerations, not recommendations. A prescriber will look at your full health picture.

Factors that may point towards Mounjaro

• Wanting the largest average weight loss seen in trials
• A higher BMI or several weight-related conditions
• Type 2 diabetes, where tirzepatide also has strong evidence for blood glucose control
• Eligibility for the NHS rollout under NICE TA1026
• Preferring weekly over daily treatment

Factors that may point towards a tablet

• A strong aversion to needles or difficulty injecting
• Frequent travel where keeping pens cool is difficult
• Wanting to maintain weight loss after a period on an injection, where a prescriber thinks this is appropriate
• For Foundayo, wanting a daily tablet without food rules
• For Wegovy tablets, wanting semaglutide in oral form

Who should not take any of them

All three share similar contraindications and cautions, including pregnancy and breastfeeding, a history of pancreatitis, severe gastrointestinal disease, a personal or family history of medullary thyroid cancer (as stated in some SmPCs), and certain eating disorders. See who should not take GLP-1 medications.

Switching between Mounjaro and a tablet

From Mounjaro to a tablet

People may consider switching because of needle fatigue, travel, cost or a wish to move to a maintenance phase. ATTAIN-MAINTAIN provides some evidence for switching from tirzepatide to orforglipron, though some weight was regained on average. There is no official dose conversion from tirzepatide to oral semaglutide or orforglipron, so prescribers make an individual judgement about the starting dose and timing. Our guide to switching from an injection to a tablet explains the considerations.

From a tablet to Mounjaro

Someone who has not reached their goals on a tablet, or who has difficulty with the daily routine, may discuss moving to Mounjaro. Mounjaro would usually be started at a low dose and increased gradually. Never take a tablet and Mounjaro at the same time.

NHS and private access

Mounjaro on the NHS

NICE recommends tirzepatide (TA1026) for adults with a BMI of 35 or more and at least one weight-related condition, with lower thresholds for some ethnic groups. NHS England began a phased rollout in primary care in June 2025, starting with people with a BMI of 40 or more and at least four qualifying conditions. Access is expected to widen over several years. See Mounjaro on the NHS.

Tablets on the NHS

At the time of writing, NICE had not recommended Wegovy tablets for weight management, and was assessing orforglipron with a decision expected later in 2026. Until NICE recommends them, the tablets are generally only available privately. Check NICE's website for the current position.

Private prescribing

Private providers can prescribe any of these medicines within their licences, after an assessment by a registered prescriber. Providers should be registered with the General Pharmaceutical Council (GPhC) or, for clinics, the Care Quality Commission (CQC) in England. See who regulates online weight loss services.

Cost: what affects it

We do not quote prices in our guides. Factors that affect private costs include:

• List prices. The UK list price of Mounjaro rose in September 2025, which changed private prices across the market.
• New launches. The tablets were launched in 2026, and early pricing may change as the market settles.
• Dose. Mounjaro prices often rise with dose; tablet pricing may be structured differently.
• What is included. Consultations, ongoing support and delivery are bundled differently by different providers.
• Long-term use. Because treatment is often ongoing, the cost over a year matters more than the first month.

See our prices page for current comparisons and the long-term cost of GLP-1 treatment.

Getting the most from whichever treatment is chosen

The licences for Mounjaro, Wegovy tablets and Foundayo all specify use alongside a reduced-calorie diet and increased physical activity. The trials behind them included lifestyle support, and the results reflect that combination. Some practical points apply whichever medicine a prescriber recommends:

• Start low, go slow. All three use gradual dose increases to reduce side effects. Staying longer at a dose is often an option if side effects are difficult.
• Eat enough protein. Appetite falls sharply on these medicines, and protein at each meal helps protect muscle. See protein on weight loss injections.
• Keep active, including strength work. Resistance exercise helps preserve muscle and bone as weight falls. See preserving muscle on GLP-1 treatment.
• Drink regularly. Reduced thirst and gastrointestinal side effects can lead to dehydration.
• Track more than weight. Waist measurement, blood pressure, energy levels and how clothes fit can show progress when the scales stall. See measuring progress beyond the scales.
• Plan for the long term. Weight tends to return when any of these medicines stops, so discuss in advance what maintenance might look like.

Questions to ask your prescriber

• Based on my health and goals, which of these options am I eligible for?
• How much weight loss is realistic for me, and how will we judge whether treatment is working?
• Would a weekly injection or a daily tablet fit better with my routine and other medicines?
• If I am already on Mounjaro, would switching to a tablet make sense for me, and what might I expect to regain?
• Do I need to change my contraception?
• What happens if side effects are difficult, and who do I contact between reviews?

What remains uncertain

• No head-to-head trial has compared Mounjaro with a GLP-1 tablet for initial weight loss.
• The long-term safety record of orforglipron, and of oral semaglutide at weight-management doses, is still being built.
• How well people keep taking daily tablets in everyday life, compared with weekly injections, is not yet clear.
• Whether NICE will recommend the tablets, and for whom, was undecided at the time of writing.

When to speak to a professional

Speak to your GP, pharmacist or prescriber before starting, switching or stopping any GLP-1 medicine. Tell them about all the medicines you take, including contraception and thyroid medicines (relevant to the oral semaglutide timing rules), and about any history of pancreatitis, gallbladder disease, kidney problems, thyroid cancer, diabetic eye disease or eating disorders. Let them know if you are pregnant, planning pregnancy or breastfeeding.

Seek urgent medical help through NHS 111, or call 999 in an emergency, if you experience:

• Severe, persistent abdominal pain, especially spreading to the back, with or without vomiting
• Pain in the upper right abdomen, fever, or yellowing of the skin or eyes
• Vomiting or diarrhoea that stops you keeping fluids down, or signs of dehydration
• Signs of a severe allergic reaction, such as swelling of the face or throat, or difficulty breathing
• Symptoms of low blood sugar if you also take insulin or a sulfonylurea

Report suspected side effects through the MHRA Yellow Card scheme. To compare regulated services, see our provider comparison.