Switching guide
Can you switch from Mounjaro injections to an oral GLP-1 tablet?
Mounjaro is currently supplied as a weekly injection. Oral weight loss options such as the Wegovy tablet, and future medicines such as orforglipron, may appeal to patients who would prefer not to continue with injectable treatment.
Switching is not a direct swap. Different medicines work in different ways, so any change should be planned with a qualified prescriber.
Please note
Foundayo, also known as orforglipron, is not currently licensed in the UK for weight management. Any mention of Foundayo on this page is for educational information only.
Clinical review required
Usually restart low
How does switching from Mounjaro to an oral GLP-1 work?
Switching from Mounjaro to an oral weight loss treatment may be possible for some patients, but it should not be treated as a simple medicine swap.
Mounjaro contains tirzepatide. Wegovy tablets contain semaglutide, while Foundayo contains orforglipron. They are related medicines, but they are not the same treatment, so there is no safe direct dose-for-dose conversion.
Patients moving from Mounjaro will usually need to begin the new tablet at the lowest starting dose, even if they were previously using a higher maintenance dose of tirzepatide. The tablet dose can then be increased gradually, if suitable.
The timing will depend on your current treatment, side effects and medical history. In many cases, a gap of at least one week from the last Mounjaro injection may be advised before starting a new tablet, but your prescriber should confirm the safest plan.
Do not stop Mounjaro or start a new weight loss medicine without speaking to a qualified healthcare professional first.
What should you expect when switching to tablets?
Most patients should expect an adjustment period in the first few weeks after changing treatment. This is especially likely if the new tablet is started at the lowest dose.
During this early stage, appetite control may feel weaker than it did on Mounjaro. That does not automatically mean the tablet is not working. Like injectable treatments, oral GLP-1 medicines usually have a stronger effect after dose increases.
Your appetite may feel stronger at first
You may feel less full after meals while restarting at a low dose
Food noise or cravings may temporarily increase
Weight loss may slow or plateau during the adjustment period
Digestive symptoms such as nausea, bloating, diarrhoea, constipation or stomach discomfort can also happen as your body adjusts. These effects are often temporary, but you should seek advice if symptoms are severe, persistent or concerning.
Will a weight loss tablet work as well as Mounjaro?
Not necessarily. Some people may continue losing weight or maintain their progress after switching, while others may feel that appetite suppression is not as strong as it was on Mounjaro.
Clinical trial results also suggest that average weight loss may differ between treatments. The figures below are not direct head-to-head comparisons, but they help explain why expectations should be realistic.
Mounjaro 15mg
Weekly injection containing tirzepatide
Around 20% average weight loss after 72 weeks
Wegovy pill 25mg
Oral tablet containing semaglutide
Around 14% average weight loss after 64 weeks
Foundayo 36mg
Oral orforglipron, not currently licensed in the UK for weight management
Around 11% average weight loss after 72 weeks
Weight loss percentage is not the only factor to consider. For some patients, the convenience of a tablet may make treatment easier to continue long-term.
Why can Mounjaro produce greater average weight loss?
Wegovy tablets and Foundayo are not oral versions of Mounjaro. They are separate medicines with different active ingredients.
Mounjaro contains tirzepatide, which works on two hormone pathways involved in appetite regulation: GLP-1 and GIP. This is known as dual agonist activity.
Wegovy tablets contain semaglutide, and Foundayo contains orforglipron. These medicines work through the GLP-1 pathway. They can still reduce hunger, increase fullness and support weight loss, but they should not be expected to feel identical to Mounjaro.
What should you consider before switching?
Your weight loss goals
If your main priority is the strongest possible average weight loss, staying on Mounjaro may be more suitable. If you have already reached your target, tablet convenience may become more important.
How you are getting on with Mounjaro
If injections are difficult, inconvenient or causing problems, a tablet may be worth discussing. If your current treatment is working well, there may be less reason to change.
What fits your routine
Tablets remove the need for injections, but they can still have specific instructions. Some patients may find a weekly injection simpler than a daily tablet.
Speak to a prescriber before changing treatment
The right option depends on your current dose, treatment response, side effects, goals and medical history. A prescriber can help you weigh up the convenience of a tablet against possible differences in appetite control and weight loss.
References
- Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine. 2022;387(3):205–216.
- Wharton S, Lingvay I, Bogdanski P, Duque R, Jacob S, Karlsson T, et al. Oral Semaglutide at a Dose of 25 mg in Adults with Overweight or Obesity. New England Journal of Medicine. 2025;393(11):1077–1087.
- Wharton S, Aronne LJ, Stefanski A, Alfaris NF, Ciudin A, Yokote K, et al. Orforglipron, an Oral Small-Molecule GLP-1 Receptor Agonist for Obesity Treatment. New England Journal of Medicine. 2025.
- Novo Nordisk. Wegovy semaglutide prescribing information. Plainsboro, NJ: Novo Nordisk.
To support ongoing safety monitoring, suspected side effects can be reported through the MHRA Yellow Card scheme.