If you’ve been on Mounjaro for a while, or even if you’re just researching it before getting started, you might have heard people say things like, “It stopped working for me after a few months,” or “I’ve plateaued.” It’s a concern I’ve seen raised in forums, heard in casual conversations, and even wrestled with myself. So let’s break it down together – from one user to another – and explore what it really means when people say Mounjaro ‘stops working’, and what you can realistically do about it. First of all, let’s start with a bit of honesty. Every weight loss journey is different. And if you’ve tried different diets, pills, injections, or plans over the years – like I have – then you already know how easy it is to feel disappointed when things start strong, only to lose momentum later on. With Mounjaro, many people see impressive changes in the first few months. For some, that includes steady weight loss, more stable blood sugar levels, reduced cravings, and just feeling more in control of their choices. But then, out of nowhere, the scales stop moving. Sound familiar?
Why Do Plateaus Happen?
Let’s get this straight: plateaus are completely normal. In fact, they’re expected. The body is incredibly adaptive, and as your weight drops, your calorie needs also shift. You’re simply not burning as many calories at a lower weight as you were at a heavier one. This natural change in metabolism can make it feel like Mounjaro is doing less than it used to. But that doesn’t mean the medication has stopped working altogether. It could just mean your body’s adjusting, and you may need to tweak a few things on your end. There’s also the psychological element. When you first start Mounjaro, there’s often a big mental shift – you’re more focused, excited, and making better food choices without even trying too hard. But as time passes and that ‘new start’ feeling fades, old habits might start sneaking back in without you noticing. And sometimes, that’s enough to stall progress.
Understanding How Mounjaro Works
To get a better grip on what’s going on, it helps to revisit how Mounjaro actually works. Mounjaro (tirzepatide) is a dual GIP and GLP-1 receptor agonist. That means it mimics two important gut hormones that help regulate appetite, insulin production, and digestion. By influencing those pathways, Mounjaro can slow gastric emptying (which helps you feel fuller for longer), increase insulin secretion (which helps control blood sugar), and reduce appetite. Over time though, some people feel that those appetite-suppressing effects aren’t as strong as they once were. This can be down to a number of things, including developing a bit of tolerance to the medication, lifestyle drift (where you unintentionally return to old habits), or changes in stress, sleep, or activity levels. There’s no solid research yet proving that Mounjaro becomes less effective long term for everyone. But real-world experiences show it can feel that way, especially after the initial rapid changes start to level out.
Signs Your Progress Might Be Slowing
So how do you know if you’re hitting a plateau or if something more serious is going on? Here are some signs that things may be levelling off:
- The number on the scale hasn’t moved in 3-4 weeks despite sticking to your habits
- You’re starting to feel hungrier between meals again
- Clothes are no longer feeling looser like they once did
- You’re not as motivated or focused as you were at the start
- You’re grazing or snacking more than you realise
Remember, none of these mean failure. It’s just data. And with the right changes, you can keep making progress.
What You Can Do About It
Here’s the good news: there are practical ways to push through a Mounjaro plateau. Most people find that with a few adjustments, their results kickstart again. These are the strategies that tend to help:
- Reassess your calorie intake
As your weight drops, your calorie needs do too. If you were eating 1,800 calories at 17 stone and losing weight, you might need to eat closer to 1,500 now to keep the loss going. Apps like MyFitnessPal or Cronometer can help you keep an eye on things without becoming obsessive. - Focus on protein
Protein helps preserve muscle during weight loss, keeps you fuller for longer, and supports metabolism. Aim for at least 1.2g of protein per kg of goal body weight per day. That could mean including lean meats, eggs, low-fat dairy, or protein shakes in your routine. - Move more (even a bit helps)
You don’t need to live in the gym, but adding movement can make a big difference. Daily walks, resistance training, or even light stretching can nudge your metabolism upwards. Consistency matters more than intensity. - Track honestly
It’s easy to forget the extra biscuit or underestimate that takeaway. Try tracking your food honestly for 3-5 days to spot any sneaky habits that might be affecting your progress. - Sleep and stress matter too
Poor sleep and high stress can raise cortisol levels, which can affect hunger hormones and fat storage. If you’ve been sleeping poorly or feeling overwhelmed, don’t overlook this area. Rest and recovery play a huge role in fat loss. - Consider your dose
Without giving medical advice, it’s worth speaking to your GP or prescribing specialist about whether your current dose of Mounjaro is still right for you. Some people benefit from an increase once lower doses plateau – but that’s a medical decision, not something to self-adjust. - Stay consistent and patient
Plateaus often feel worse than they are. The key is to stay consistent and ride them out. Weight loss isn’t linear – and just because it’s slowed, doesn’t mean it’s stopped.
What the Research Says
While there are limited long-term studies on Mounjaro compared to older drugs like Ozempic, early results are promising. In the SURMOUNT-1 trial, participants taking tirzepatide lost up to 22.5% of their body weight over 72 weeks, depending on the dose. That’s more than any other GLP-1/GIP drug on the market. Source: NEJM – Tirzepatide Once Weekly for the Treatment of Obesity. Importantly, even though weight loss slowed after the first six months, participants continued to lose weight over the full trial period. That means the drug can keep working long term if supported by the right habits and medical supervision.
Is It Worth Staying on Mounjaro?
Only you and your healthcare provider can answer that for sure. But from a user’s perspective, if you’re seeing benefits beyond just the scales – like better blood sugar, more control over cravings, improved energy or confidence – those things matter too. Progress isn’t always measured in pounds lost. Sometimes it’s about how you feel, how you eat, and how you show up in daily life. If you’re stuck, don’t panic. Take a breath, look at your habits, maybe track things for a bit, and speak to your doctor if needed. Mounjaro can still be a powerful tool on your journey – even if it needs a bit of tweaking along the way.
Final Thoughts
If you’ve hit a plateau or feel like Mounjaro is doing less than it used to, know you’re not alone. It happens. It doesn’t mean you’re failing, and it certainly doesn’t mean your journey is over. Use it as a chance to pause, reflect, and recalibrate. Stay consistent. Stay kind to yourself. And keep going – you’re further ahead than you think.
