How long can you be on weight loss injections?

Does NICE set a time limit for weight loss injections?

The short answer is: it depends on which injection. NICE's guidance on semaglutide (Wegovy) states it should be used for a maximum of two years, and only within a specialist weight management service that provides diet, activity and behavioural support alongside the medicine. That two-year ceiling reflects the evidence base available when the guidance was written, and NICE also advises that treatment should be reviewed if someone has not lost at least five per cent of their starting weight after six months on the maintenance dose.

Tirzepatide (Mounjaro) sits under a different NICE appraisal (TA1026, published in December 2024) and that guidance does not impose the same two-year cap. The same five-per-cent review trigger applies, but otherwise duration is left to clinical judgement. For people accessing either medicine privately, the licensed indications and SmPC inform the prescriber's decision rather than NHS commissioning rules, so the picture can look slightly different outside the NHS setting.

One practical consequence of these differences is that someone switching from Wegovy to Mounjaro at the two-year mark is not automatically stopping treatment, they may be moving to a medicine with a different evidence framework. That kind of transition should always be discussed with a prescriber, and if you want to understand how long you can use weight loss injections across different medicines, we cover that in detail. You can read more about the broader options on our weight loss injection overview.

What happens to weight when you stop the injections?

This is the question our prescribers hear most often, and the honest answer comes directly from the trial data. In the STEP 1 extension study, participants who stopped semaglutide regained most of the weight they had lost within a year of stopping, while those who continued maintained their results. Similar patterns were seen with tirzepatide. The NHS patient information for tirzepatide notes that the medicine works as part of a long-term lifestyle programme, stopping it without sustainable diet and activity changes in place makes regain likely.

This biology is not a failure of willpower. Appetite-regulating hormones that the medicine helps to moderate tend to reassert themselves after stopping, and the body defends its previous weight set-point. Researchers are increasingly treating obesity as a chronic condition that may require long-term management, much like blood pressure or cholesterol. That framing shapes how prescribers think about duration: the question is not "when do we stop?" but "does ongoing treatment still benefit this person and remain safe?" If you are weighing up your own situation, our page on how long you can take weight loss injections walks through the clinical factors that inform those decisions.

For anyone thinking about what a longer course might involve, the weight loss injection course page covers how treatment is structured from the first dose onward.

How does a prescriber decide whether to continue your treatment?

At every repeat, a clinician should be asking three questions: is the medicine still working, are the benefits still outweighing any side effects or risks, and are there any new health factors that change the picture? This is not a box-ticking exercise. Blood pressure, weight, tolerability and any symptoms that have emerged all feed into that assessment.

At nume, a GPhC-registered prescriber personally reviews each repeat request, your consultation does not pass through an automated queue. The review happens the same working day, and if treatment is approved, your pen is dispatched in time to arrive the next working day via DPD. If you order by noon on a weekday, it fits neatly into the day before an aftercare call or a GP appointment, the kind of timing that takes a small logistical worry off the table.

For people currently on treatment elsewhere and wondering whether their duration is appropriate, our FAQs cover transfer queries, and our contact page connects you to our aftercare team directly.

Is there a point at which injections should always be stopped?

Yes. Both medicines should be stopped if you become pregnant, are breastfeeding, or are actively trying to conceive, they are not recommended during pregnancy and the guidance advises using reliable contraception throughout treatment. Neither medicine is licensed for people under 18. There are also clinical situations (certain thyroid conditions, a history of pancreatitis, specific gastrointestinal disorders) where a prescriber may decide stopping is necessary regardless of how well weight loss is going.

Beyond those absolute situations, a prescriber might recommend pausing or stopping if side effects remain troublesome over an extended period, if there is a planned surgical procedure (anaesthetists should know you are on a GLP-1 medicine), or if weight has stabilised at a level where the risk-benefit balance shifts. Our dedicated page on how long you can stay on weight loss injections explores that risk-benefit thinking in more depth. The treatment overview at nume sets out how these clinical decisions are made at every stage. Cost is a real-world factor for many people too, if you want to understand what longer-term private treatment typically involves financially, our guide to the cost of weight loss injections covers what goes into the price and what to watch for.