What to expect after the first month of using Mounjaro

Wednesday, February 26, 2025

Originally designed as a drug for diabetes, Mounjaro has become one of the most popular weight loss and weight management treatments available.

This injection contains tirzepatide, an active ingredient that suppresses appetites to prevent overeating. At Oxford Online Pharmacy, Mounjaro UK injections can be purchased as 2.5mg, 5mg, 7.5mg, 10mg, 12.5mg, or 15mg. While all patients start with the lowest dose before increasing the dosage as required, the benefits can start to take effect very quickly.

But what should you expect from Mounjaro's weight loss results over the first month and beyond? Our quick guide will reveal all.

Things to know before starting Mounjaro UK

Before looking at Mounjaro results before and after using the injectables for one month, you must familiarise yourself with what to expect.

Firstly, everyone is different. While some people notice appetite suppression, weight loss, and feelings of fullness in the first month, others may take a bit longer. Even if the Mounjaro results 4 weeks in fall short of the expectations, it may be worth continuing the treatment. Not least because the option of an increased dosage is available.

There are also several potential Mounjaro side effects to consider. They include nausea, vomiting, diarrhoea, constipation, headaches, fatigue, bloating, dizziness, and more. Most are mild but you should call a doctor if you experience hives, oral swelling, fainting, or shortness of breath.

How to maximise your Mounjaro results

Mounjaro UK is one of the most popular weight management treatments with studies showing that almost 90% of patients (1) on 5mg injectables can lose at least 5% of their body weight over an extended trial.

However, anybody seeking the best Mounjaro results must integrate the treatment into a more holistic lifestyle change. The following tips may help;

Make a conscious effort to reduce your calorie intake. A daily 500-calorie deficit (2) will help patients lose one pound of fat per week.
Consciously choose the right foods, opting for single-ingredient foods rather than ultra-processed alternatives.
Consider creating a fasting window, such as not eating after 6 pm.
Stop eating when you feel full, and stay hydrated to avoid confusing thirst with hunger.
Try to exercise more frequently, starting out with low-impact activities like swimming and walking.
Adopt a healthier and more consistent sleeping pattern.
Try to reduce your stress levels, as cortisol can impact weight loss by encouraging you to turn to food to relax.

When you adopt a healthier lifestyle, you should see better Mounjaro results 4 weeks in while also supporting sustainable progress.

Typical Mounjaro 1 month results & timeline

Individual patients may experience different results based on a number of factors ranging from their start weight to the effectiveness of Mounjaro on their appetite.

Mounjaro before and after results in week 1

When first starting Mounjaro treatments, you must first read the instructions to understand how it works and how to administer the weight loss drug. For best results and consistency, we recommend that you take the weekly injection at the same time and day each week. So, it’s important to take this into account ahead of the first injection.

Generally, it takes 72 hours (3) for Mounjaro to reach its maximum levels, although many patients will experience reduced appetites even sooner. You may also experience the mild side effects from the 2.5mg injectable.

The before and after results within the first week of taking Mounjaro can fluctuate greatly between individuals. Any significant weight loss is likely to be from lost water weight. Eating fewer calories will see glycogen stores leave the body, which also means losing 3g of water for each one gram of glycogen.

While weight loss in the first week can put you in a positive mindset, you should not worry too much about the scales at this time.

Mounjaro results in week 2

Even after two weeks, Mounjaro results are relatively small when looking at the scales. Most patients should expect to lose less than 1% of their body weight in this time. However, the second injection can start to have a more noticeable impact on hunger cravings and the types of food you want to eat.

Foods containing high levels of sugar and fat, such as ultra-processed foods, are likely to feel less tempting. Moreover, you should notice that you feel less hungry in between meals while portion control may feel easier to manage.

As well as eating less, you may find yourself drinking less water. So, a conscious effort to stay hydrated is important at this stage of Mounjaro UK weight loss plans. Any side effects experienced in week one should feel milder.

By now, the 2.5mg dosage is in your bloodstream with greater stability. So, the benefits should be more consistent.

Mounjaro UK results in week 3

In the third week, you will take another 2.5mg injection. This remains the lowest dosage, which is likely to result in a slower weight loss. However, your weight should be moving in the right direction at this stage. Moreover, the pounds lost are from fat, which is the aim.

At this stage, any side effects will be minimal, which makes the treatment feel comfortable and convenient.

While the scales might not show a major difference, you may notice a change in the way you look and feel. Clothes may fit better and mobility could improve. When you compare what a pound of fat looks like compared to a pound of muscle, you will start to appreciate the progress.

By this stage, your appetite will be noticeably reduced compared to what it once was. Eating less than normal without thinking too much about it puts you on the path to sustained results.

Mounjaro before and after results in week 4

The fourth injection may be the last you take at the 2.5mg dosage. Weight should be moving in the right direction by the end of this week. While some may lose around 5% of their body weight by this stage, the true definition of success comes from a new relationship with food.

By now, eating habits should be greatly improved. Portions are smaller. Food choices are healthier. And sugar cravings are almost non-existent. Moreover, the mild symptoms should have disappeared by this stage of the Mounjaro journey.

As long as no major side effects have occurred by now, the dosage may increase from the fifth week. In turn, this can accelerate weight loss over the coming weeks. Even if you stay at the 2.5mg dose, though, the key is that you are moving in the right direction.

The results after one month will include some weight loss, a change in physique, and a better relationship with food. Crucially, having got through the hardest phase of following a long-term weight management plan, patients will now be ready to lose fat and keep it off.

Mounjaro weight loss results beyond 4 weeks

Weight management isn’t a quick fix. So, while you may notice benefits within the first month, Mounjaro weight loss results are equally dependent on what you continue to do.

Clinical studies have often put patients on the injectables for up to 72 weeks (1). Patients will often come off the injectables before this time but will take them for longer than one month. Here’s what to expect:

The first dosage increase occurs in weeks 5 to 8, which may result in some side effects returning. However, many patients have lost around 5% of their body weight (4) and will now begin to notice a more consistent weight loss phase rather than big fluctuations.
In weeks 9 to 12, another dosage increase may be used, although many patients remain on the lower dosage. Either way, weight loss has continued and hunger between meals should have dramatically decreased.
After week 13, another increase in dosage is available. Again, this could impact side effects as the body gets used to the change. However, managing hunger will feel even easier. Once you increase to 15mg, you cannot go any higher.

As with any treatment for weight loss, Mounjaro results can vary from one person to the next. However, the weekly injectable is shown to be one of the UK’s most effective. When used as a part of an improved lifestyle, it can support the weight loss journey.