What Happens After Mounjaro? New Research Reveals Long-Term Weight Loss—and What Comes Next

If you’ve ever wondered how long you can stay on Mounjaro—or what happens when you stop—it turns out you’re not alone. Two major research presentations at the 2025 European Congress on Obesity have just shed new light on both ends of the story: what sustainable weight loss looks like over three years on Mounjaro, and what happens when people stop taking it.

The results offer plenty to celebrate—but also raise important questions about the long-term journey ahead for those of us using medications like Mounjaro to manage weight.

A Rare Look at What Three Years on Mounjaro Really Looks Like

A new analysis from the SURMOUNT-1 trial has given us the most detailed picture yet of long-term weight loss on Mounjaro (tirzepatide). Over 700 participants with obesity or overweight (and prediabetes) were studied across a full 176-week period—that’s more than three years.

The results? Remarkably positive.

Researchers found three typical patterns of weight loss:

• Steady (9.2% body weight lost)
• Medium (20.2% lost)
• Rapid (30.8% lost)

Each group accounted for about a third of participants. While everyone plateaued eventually, those who lost weight fastest reached their plateau later and maintained the greatest reductions overall. On average, the lowest weight was hit around the 22-month mark, with participants down 23.1% from their starting weight.

By the end of the study, most people had regained only a small amount—averaging out at 19.4% weight loss from baseline. Around 70% of participants regained less than 5% of their starting weight after hitting their lowest point.

That’s a powerful sign that Mounjaro doesn’t just help people lose weight—it helps keep it off, too.

But What Happens When You Stop?

While SURMOUNT-1 shows us what sustained use can achieve, another study presented just days later—this time from the University of Oxford—looked at the other end of the spectrum: what happens after stopping weight-loss injections like Mounjaro or Wegovy?

The short answer: most people regain the weight they lost, and faster than expected.

Drawing from 11 studies involving 6,370 adults, Oxford researchers found that people on semaglutide or tirzepatide lost an average of 16kg, but gained back 9.6kg within just 12 months of stopping. That suggests a full return to original weight is likely within about 20 months if no further support is in place.

Crucially, this rebound happened much faster than weight regained after stopping a diet alone—where people took at least five years, on average, to drift back to their starting point.

Professor Susan Jebb, who led the analysis, explained:

“These drugs are very effective at helping you lose weight, but when you stop them, weight regain is much faster than after stopping diets.”

The reason? Dieting builds behavioural coping strategies—taking a weekly injection does not. So when the medication is withdrawn, and appetite returns full-force, people may feel overwhelmed and unsupported.

The Role of Lifestyle Support—And a Warning Against the “Quick Fix” Mindset

Health experts say these findings should shift how we think about weight-loss injections. They are not stand-alone fixes—they are a tool in a much broader picture.

Dr Jane Ogden, Professor of Health Psychology at Surrey University, puts it clearly:

“There’s no point just throwing people back out into their old lives… They’re going to need psychological counselling, behaviour change, and nutritional support from that moment on.”

Tam Fry of the National Obesity Forum echoed this with a blunt truth:

“It shouldn’t surprise anyone if people regain weight having used GLP-1 drugs without seriously attempting to improve their lifestyle.”

This is where long-term planning matters. Behavioural support, nutritional education, group programmes, or even online communities like Life on Mounjaro all play a role in helping us bridge the gap between where we are—and where we want to stay.

Why NICE Limits Mounjaro Use to Two Years—and Why That Might Change

In the UK, current NHS guidance limits use of Mounjaro and similar weight-loss jabs to a maximum of two years. This recommendation from NICE (National Institute for Health and Care Excellence) is based on:

1. Trial Duration – Most studies, like STEP 5 and SURMOUNT-1, ran for 2 years or less. Long-term safety and efficacy data beyond that is still limited.
2. Cost-Effectiveness Models – NICE’s analysis found diminishing returns when medications are continued beyond two years, especially if paired with rising costs.
3. Service Structure – NHS specialist weight management services usually offer structured support for up to two years. The medication timeframe mirrors this care window.

However, the latest Oxford findings challenge whether a two-year cap makes sense. If weight regain happens quickly after stopping, is the short-term model truly effective—or should we treat these medications more like lifelong therapies, similar to how we manage high blood pressure or type 2 diabetes?

As NICE reviews emerging evidence, this may well be an area to watch.

The Takeaway: Medications Help—but Support Sustains

These new studies confirm what many Mounjaro users already know from experience:

• Yes, the medication works—and works well.
• Yes, weight loss can be sustained if the medication continues.
• But stopping suddenly—without support, planning, or changes to lifestyle—can lead to rapid rebound.

For those of us using Mounjaro, that means two things:

1. Celebrate the results, especially the progress sustained over time.
2. Plan ahead—whether that’s through nutritional coaching, movement habits, mental health support, or connection with others on the same journey.

At Life on Mounjaro, we’re here to support that journey—whether you’re at the start, the middle, or wondering what comes next.

Want to talk about your experience?

If you’re using Mounjaro or thinking about what life might look like after it, we’d love to hear from you. Drop us a message (@mounjaro.life) or visit the Mounjaro Stories section to see how others are navigating their path.