Switching from Wegovy to Tirzepatide: What You Need to Decide

Why people consider making this switch

Wegovy (semaglutide 2.4mg) has a strong evidence base. The STEP 1 trial, published in the New England Journal of Medicine, reported average body-weight reductions of around 15% over 68 weeks. For many people, that is a meaningful result. But some reach a plateau, tolerate semaglutide poorly at higher doses, or simply want to understand whether tirzepatide might offer more, and whether switching from semaglutide to tirzepatide is the right move for them.

Tirzepatide (Mounjaro) works differently. Where semaglutide activates only the GLP-1 receptor, tirzepatide activates both GLP-1 and GIP receptors simultaneously — the only dual-agonist licensed for weight management in the UK. In the SURMOUNT-5 head-to-head trial, tirzepatide produced greater average weight loss than semaglutide 2.4mg over 72 weeks. A fuller breakdown of how the two medicines compare sets that trial data in context alongside eligibility and side-effect profiles.

Other people switch for practical reasons: needle anxiety, injection-site reactions, or wanting to explore the newer oral semaglutide option before committing to tirzepatide. Whatever your reason, the first question a prescriber asks is whether the switch is clinically appropriate for you specifically.

What a prescriber looks at before approving the change

A switch is not simply stopping one pen and starting another. Your prescriber will want to know how long you have been on Wegovy, which maintenance dose you reached, how much weight you lost, and whether you experienced any significant side effects. These details matter because they inform both the clinical rationale for switching and, if a switch is approved, where to begin on tirzepatide's dose ladder.

Tirzepatide starts at 2.5mg, a tolerability step whose job is to let your system adjust before the therapeutic work begins. Whether a prescriber moves you through that starter phase at the standard pace or adjusts it depends on your individual picture, including your GI tolerance history on semaglutide.

There is also a wash-out consideration. Because both medicines slow gastric emptying and carry overlapping GI side-effect profiles, doubling up is not appropriate. A prescriber will advise on timing. If you are also using oral contraceptives, tirzepatide requires an additional precaution: NHS England's guidance recommends adding a non-oral contraceptive method for the first four weeks of tirzepatide treatment and after each dose increase, because pill absorption may be reduced.

How Wegovy and tirzepatide sit alongside each other (at a glance

Both medicines are Black Triangle (▼) products, meaning they carry additional MHRA monitoring. Neither figure in the table is a guarantee, individual results vary, and the SURMOUNT-5 comparison was conducted under specific trial conditions. The Wegovy vs Mounjaro page goes deeper on the evidence, and if you are also weighing up cost, the price difference between the two treatments is explained there plainly.

How the switch works in practice at nume

At nume, every change to your treatment (including a switch between medicines) goes through a full clinical re-review. A real prescriber reads your case; our clinical team does not delegate that to a form or an algorithm. If you are transferring from another provider, you will be asked for evidence of your current treatment and dose, which protects you as much as it protects clinical standards.

Once a switch is approved before midday on a working day, your tirzepatide is dispatched the same day. It arrives the next working day via tracked DPD, in plain packaging. Tirzepatide pens are refrigerated, most people keep theirs in the fridge door, and the pen stays there until injection day. Your prescriber and our aftercare team remain available seven days a week if questions come up as you adjust.

If you have already been exploring this question, the step-by-step guide on switching from Wegovy to tirzepatide covers timing and what to expect in more detail. For anyone coming from Ozempic rather than Wegovy, note that Ozempic is semaglutide licensed for type 2 diabetes, not weight management, the Ozempic to Mounjaro switching page addresses that different starting point. Ultimately, which medicine suits you is a clinical decision our prescribers make with you, not one this page can make for you.