What are the long-term effects of Wegovy on your health?

Weight loss and cardiovascular outcomes: what the trial data found

The clearest long-term picture comes from SELECT, a cardiovascular outcomes trial involving over 17,000 adults with obesity and established cardiovascular disease but without diabetes. Published in the New England Journal of Medicine and discussed in NICE's appraisal of semaglutide (TA875), SELECT showed that semaglutide 2.4 mg reduced the risk of major cardiovascular events (heart attack, stroke or cardiovascular death) by around 20% compared with placebo over a median follow-up of just over three years. That finding shifted how regulators and clinicians think about this medicine. Weight reduction alone does not fully explain it; researchers believe the GLP-1 receptor pathway has direct effects on inflammation and cardiac function.

On weight itself, the STEP 5 trial followed adults for 104 weeks, two full years. Participants maintained most of their weight loss across that period, with an average reduction of around 15.2% at week 104. Importantly, a separate study showed that people who stopped semaglutide after one year regained a significant portion of the lost weight within the following year. That has clinical implications: Wegovy is most effective as a longer-term treatment, not a short course, and our guide to Wegovy long-term use covers what that commitment realistically involves. Whether that suits you is exactly the kind of conversation to have during a clinical assessment, which you can explore via our Wegovy treatment information.

Side effects that persist versus those that resolve

Nausea is the most commonly reported side effect and is almost always tied to dose escalation. The 0.25 mg starting dose exists precisely to let your system adjust before the gradual climb toward 2.4 mg. For most people, nausea fades considerably once they reach and settle at maintenance. Vomiting, diarrhoea, constipation, indigestion and fatigue follow a similar pattern, prominent early, quieter later.

What requires longer-term vigilance is rarer. The MHRA's January 2026 Drug Safety Update for GLP-1 medicines specifically highlighted acute pancreatitis: the risk is infrequent, but it can be serious. Severe, persistent stomach pain that spreads to the back (with or without vomiting) needs prompt medical attention, not a wait-and-see approach. Gallbladder problems, including gallstones, have also been reported at higher rates with semaglutide than with placebo in trials. The NHS semaglutide information page lists these in detail and explains which symptoms should prompt a call to your GP or 111 rather than waiting for your next review.

Wegovy carries a Black Triangle (▼) in the UK. It simply means the MHRA requires enhanced post-market reporting. Any suspected side effect can be flagged at the Yellow Card scheme, which is open to patients as well as healthcare professionals. Worth doing, it genuinely informs future guidance.

What happens to weight when treatment continues beyond two years

This is the question fewer people ask, but it matters. The honest answer is that robust, long-duration data for semaglutide specifically at 2.4 mg is still accumulating. What SELECT demonstrated over three-plus years is that the medicine continues to confer cardiovascular benefit even when weight plateaus. That plateau is expected. The body adapts to a lower set point, metabolism adjusts, and weight loss naturally slows and then stabilises, this is not a sign the medicine has stopped working.

NICE recommends semaglutide for a maximum of two years within a specialist weight management service under TA875. Private prescribing follows clinical judgement on a case-by-case basis. Stopping is associated with weight regain, which is why the decision about duration should be made with a prescriber who knows your health picture, not based on a fixed timeline alone. For a fuller look at how the evidence stacks up over an extended period, the long-term effectiveness data is worth reading before that conversation.

Cost, NHS access and what ongoing private treatment involves

One practical long-term consideration people rarely factor in early is cost. The pen lives in the fridge (realistically the fridge door, since it is used weekly) and the question of who pays for it over months or years becomes real. NHS access to Wegovy under NICE TA875 is via specialist weight management services, with waiting lists that vary considerably by area. Private treatment removes the wait but requires an ongoing transparent budget.

On the cost of Wegovy in the UK, prices vary by dose and provider; any legitimate private price covers the clinical assessment and prescription, not just the pen. At nume, a named prescriber (not software) reviews your case before every repeat order, and there is no subscription locking you in. Speak to our prescribers if you want to understand whether Wegovy fits your longer-term health goals and circumstances.