Does Mounjaro burn fat? Understanding how it supports weight and fat loss

It feels like just yesterday that we all started hearing about Ozempic, and wondered if it was really the promising weight loss solution it appeared to be. While, as it turned out, the hype was real, the medication continues to be prescribed primarily for the treatment of type-2 diabetes rather than weight loss.

However, since then, a crop of other weight loss injections have popped up, including Wegovy, Saxenda and Mounjaro. The latter in particular is attracting a lot of attention recently, thanks to growing evidence that Mounjaro may be the most effective medication in its category.

Clinical trials and real-world data show that patients have better weight loss outcomes on Mounjaro and its close relative Zepbound, compared to other weight loss and diabetes medications [1]. But, what makes tirzepatide — the active ingredient in Mounjaro — so effective for fat loss, exactly?

Whether you're just starting your medical weight loss journey or are using another medication and are wondering if there's a more effective option, here's everything you need to know about Mounjaro.

What is Mounjaro and how does it work?

Mounjaro is the brand name for the injectable weight loss medication, tirzepatide. It's administered via subcutaneous injections once weekly, at the same time each week.

Mounjaro was originally created to treat type-2 diabetes, thanks to its ability to control blood sugar levels. However, it can also be prescribed to eligible patients to treat excess weight and obesity.

How does Mounjaro support weight loss?

Like Ozempic and Wegovy (semaglutide), Mounjaro is part of a class of medications called glucagon-like peptide-1 (GLP-1) agonists. However, its active ingredient, tirzepatide, works in a slightly different way to promote weight loss.

Mounjaro is known as a 'twincretin' medication, in that it not only works on GLP-1 but also GIP — gastric inhibitory polypeptide [2]. With these natural hormones playing an important role in regulating blood sugar, tirzepatide binds to their respective receptors to stimulate insulin release.

Controlling blood sugar levels is important for creating the right conditions for weight loss. When they're out of whack, we tend to store excess calories as body fat. Plus, irregular blood sugar tends to lead to more food cravings — like, when you eat breakfast and are already reaching into the snack drawer an hour later!

Mounjaro and other weight loss injections also help patients lose weight by keeping them full for longer. The GLP-1 mechanisms send signals to the brain that we're satiated even when we eat smaller portions of food. They also delay gastric emptying, which further contributes to the fullness. Working together, all of these help patients reduce their caloric intake and lose weight more effectively.

So, how much weight can you lose on Mounjaro, exactly? Of course, the answer depends on your lifestyle, starting weight and how much you have to lose. That said, clinical trials show Mounjaro patients can lose up to 4% of their body weight in the first month [3]. This increases to around 25% of their starting weight over one year, compared to 15% on Ozempic in the same timeframe [4]. For a person with a body weight of 150 kilos, this could be the difference between losing 37 or 22 kilos.

Other studies estimate that Mounjaro's average weekly weight loss is 0.19–0.28 kg/week compared to 0.14 kg/week for Ozempic — firmly positioning it as one of the most effective weight loss medications on the market [5].

Does Mounjaro boost your metabolism?

While some medications (think, old-school diet pills) work by speeding up your metabolism, this tends to be unsustainable and come with a host of unpleasant side effects — think, feeling of jitteriness and a fast heart rate.

Mounjaro, on the other hand, regulates your metabolism. So, if you have underlying health problems that may impact your ability to lose weight (such as type-2 diabetes, insulin resistance or PCOS), Mounjaro can help address this at a biological level. That means, weight loss doesn't have to feel like as much of an uphill battle.

Does Mounjaro burn fat directly?

Strictly speaking, Mounjaro and other similar weight loss medications do not shed fat by themselves. Rather, they have an indirect impact on fat loss. These weight loss drugs have several mechanisms that regulate appetite and metabolism. This results in eating fewer calories, which leads to fat loss over time.

What is the difference between weight loss and fat loss?

It's important to differentiate between weight loss and fat loss, as the two aren't always one and the same. There are actually six different types of body fat: essential, brown, white, beige, and visceral, with the latter two being the type that contributes the most to our body appearance [6].

Subcutaneous fat is the fat on the skin's surface that you can pinch, while visceral fat is under the surface surrounding your organs (which can contribute to a protruding look).

When we lose weight, we can lose any combination of these types of fat. But, we also tend to lose water weight (especially in the beginning), glycogen, food waste and muscle.

Often, when we say we want to lose weight, what we actually mean is that we want to lose fat while maintaining muscle. This is why an intentional approach is so important, especially while taking a weight loss medication like Mounjaro.

Can Mounjaro help reduce belly fat?

It's important to note that apart from surgical interventions, there is no way to spot reduce fat. That is, fat distribution is unique (and usually, genetic), and we unfortunately can't choose where we lose it from.

That said, stomach fat and blood sugar tend to be closely associated, especially in women with metabolic and hormonal issues [7]. So, some patients find that the medication helps to shift excess fat in this area in particular and helps to reduce that 'apple-shaped' look.

How to maximise fat loss while on Mounjaro

Mounjaro isn't a silver bullet for fat loss — you still need to meet the medication half-way with a healthy lifestyle. That said, there are some simple strategies you can use to maximise your results.

Prioritise protein

The flip side of fat loss is muscle maintenance (or, even muscle gain!) The more lean mass you have, the more efficient your body is likely to be at burning fat. In other words, your metabolism becomes like a finely-tuned furnace.

This is why the Juniper Programme has a strong focus on protein intake, ensuring you get enough of it even when you're eating smaller portions of food. This also helps to set you up for long-term weight loss success, as maintaining lean muscle mass reduces the risk of weight regain if you stop taking Mounjaro.

Get active

You don't necessarily need a rigorous exercise routine to lose weight on Mounjaro. That said, the more active you are, the more likely you are to be in a calorie deficit (which is how fat loss occurs).

Consider how you could burn just a few extra hundred calories per day. If you have a sedentary desk job, this could involve just sneaking in a 20-minute brisk walk on your lunch break. Or, perhaps there's a fitness class or running group you've been considering joining in your area.

Break through weight loss plateaus

It can be frustrating when you're steadily losing weight and all of a sudden, it just stops. This is especially true when you have stubborn areas where the fat just won't seem to budge.

As your body adjusts to the medication and your new way of eating, sometimes it can be a good idea to give the body a bit of a shakeup. Think, adding some extra protein into your breakfast or experimenting with your dinner timings. Sometimes, this can be just what you need to bust through the plateau and start losing fat again.

Embrace non-scale victories

Sometimes, all we need is a perspective shift. Even with the more advanced body fat scales on the market, they don't always capture the full picture of your weight loss. Because they can't always differentiate between fat and muscle, you might be losing weight and toning up without even realising it!

So, be sure to take the number on the scales with a grain of salt and celebrate other wins — like your jeans fitting more comfortably or a more compact mid-section.

Consider a holistic weight management program

While Mounjaro is a highly effective weight loss medication, not everyone loses fat in the same way. To really maximise your results, a personalised approach is needed.

The Juniper Programme combines weight loss medication with dietitian-led health coaching and tracking, so you can lose weight and reach your goals for good.

Kickstart your weight loss journey with Wegovy or Mounjaro, two groundbreaking weight loss medications that mimic the GLP-1 and GIP hormones, respectively, to help control cravings, delay stomach emptying, and keep you feeling fuller for longer. These clinically backed treatments help members experience up to 20% body weight loss.

Plus, we have a team of expert dietitians and health coaches you can consult with to help you work through any challenges you're experiencing during your weight management journey. This approach sets you up for sustained weight loss, rather than a quick-fix solution.

This means you can continue to enjoy the things you love in moderation without ever feeling deprived.

Ready to see if Juniper is right for you? You can check your eligibility here.

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