How Long Does Mysimba Take To Work?

When researching weight loss treatments such as Mysimba, several factors should be considered. It’s important to understand how much weight you could lose, what side effects might occur, and how to administer the medication.

Something else you may be interested in is how long it takes your chosen treatment to start supporting your journey. Different medications will take different lengths of time, while there is usually a gap between the active ingredient taking effect and you starting to notice signs of weight loss.

In this article, we answer the question “How long does Mysimba take to work?” We’ll also explore the factors that could affect the treatment’s efficacy and highlight success stories from Mysimba customers. Let’s begin. 

START YOUR MYSIMBA CONSULTATION TODAY

What is Mysimba Used For?

Mysimba is a prescription weight loss medication for people who are overweight or obese. It's usually prescribed to people with a Body Mass Index (BMI) of over 27 and those struggling with weight-related health complaints, including high blood pressure, diabetes, or high levels of fat detected in the blood.

Mysimba contains two active ingredients: naltrexone and bupropion, both licensed in the EU. These active ingredients reduce your appetite by acting on parts of the brain known to control how much we think we need to eat and our energy levels.

Additionally, naltrexone and bupropion can reduce the pleasure you get from eating. This can help reduce the likelihood of you overeating or “emotional eating.”

How Long Does Mysimba Take to Work?

Mysimba is absorbed into your body within a few hours. However, exact times can vary depending on your metabolism and other factors, such as whether you take the medication on an empty or full stomach.

The treatment will start to work from the first tablet, but it will take a few weeks for its full effect to be reached. You may notice a gradual change in your appetite during this time. However, you may have to wait up to eight weeks before seeing any significant weight loss.

How Long Should I Take Mysimba For?

You can take Mysimba for as long as needed. You will need a 16-week check-up with your doctor, followed by annual check-ups. After 16 weeks, your doctor will check if you’ve lost at least 5% of your starting body weight. Your doctor will recommend that you stop Mysimba if you:

• Haven’t lost at least 5% of your starting body weight
• Experience intolerable side effects that are not going away
• Have high blood pressure
• Become pregnant

Risks and Benefits of Long-term Use

Mysimba can have some risks with long-term use, such as:

• High blood pressure
• A slightly increased chance of having a seizure (1 in 1,000)
• Mental health problems, such as depression
• Lupus

Your doctor will monitor your health while taking Mysimba, and you can stop the medication at any time, as long as you speak to a healthcare professional first.

Mysimba can also have some benefits with long-term use, such as:

• Weight loss, which can improve other health conditions, such as diabetes, and increase your life expectancy
• A decrease in appetite, which can help you make long-lasting changes to how you eat
• Improved confidence and self-esteem

Mysimba

Rated 1.0 out of 5 based on 1 reviews

Rated 1.0 out of 5 based on 1 reviews

• Reduces cravings & emotional eating 
• Convenient, twice-daily oral treatment 
• Proven weight loss results

• Discreet delivery next working day
• Online prescription - No doctor visit

Prices from £109.99 Review More Prices

Start Order More Info

Get Started

Start Order More info

How Effective is Mysimba? Potential Mysimba Results

Data published by the European Medicines Agency highlights several studies that concluded Mysimba is an effective treatment for weight loss. In three of the studies, patients were given Mysimba or a placebo in combination with a weight loss programme. The weight loss programme included counselling, dietary advice, and regular exercise.

The average weight loss for patients taking Mysimba was around 3.7 to 5.7%, compared with 1.3 to 1.9% among the placebo group. The weight loss was even greater in a fourth study, which required patients to undergo a more intense therapy and counselling program.

By the end of the trial, the average weight loss for those taking Mysimba in conjunction with intense counselling sessions was 8.1%. In contrast, those taking a placebo alongside their therapy sessions lost an average of 4.9%.

Factors that Affect the Efficacy of Mysimba

Several factors can interfere with Mysimba and reduce its effectiveness. Mysimba will not work on its own and requires a serious commitment to changing your lifestyle. That means following a weight loss diet plan and increasing the amount of physical activity you do.

The effects of Mysimba also depend on how your body responds to the medication. You may lose more or less weight than the average weight loss in clinical trials because of differences in your metabolism, lifestyle, and overall health.

It’s also not recommended to take Mysimba after the age of 75, while individuals over 65 will need to exercise caution. If you have a pre-existing health condition or are taking certain medications, Mysimba may work differently. Your clinician will discuss this with you when prescribing.

Consistency is another factor that can affect Mysimba’s efficacy. Missing doses may cause fluctuations in the amount of medication in your system, which can not only increase the risk of side effects but also affect the amount of weight you could lose.  

Overall, the effectiveness of Mysimba depends on its mechanism of action, combined with your commitment to making lifestyle changes to support your weight loss journey. 

What to Do If You Find the Dose Ineffective

If you find your Mysimba dose is not effective, wait a few weeks after starting treatment. Your doctor will check in after 16 weeks, but you can speak to them sooner if you don’t think Mysimba is working for you.

Do I Have to Follow a Diet and Exercise Plan on Mysimba?

Simply taking Mysimba and making no other lifestyle changes is likely to be ineffective for weight loss. Mysimba is a supplementary treatment that supports a wider weight loss plan. This plan typically includes exercise tailored to your current fitness level and a calorie-controlled diet consisting of healthy foods.

Mysimba Success Stories

Clinical trial data can provide helpful insights into the effectiveness of weight loss medications, but they are only one aspect to consider. Stories from real-life Mysimba users can provide valuable insights into what to expect, how to manage side effects, and how effective it can be. In this section, we discuss some of the reviews Prescription Doctor patients have left about Mysimba.

Many Mysimba users have shared how the medication has helped to reduce their appetite and support significant weight loss. Traci Morrow said:

“I have just started my prescription 4 days ago, and I can honestly say it is curbing my appetite and my thoughts about food. I’m hoping as I get into the weeks, it will continue to benefit me.”

Most users do not report severe or significant side effects and state that they wear off after a few days of taking Mysimba, like Joanna Basik, who said, 

“Very good product when you keep watching what you eat. First 4 weeks lost 6kg with minimal exercise. Side effects gone after 3rd day.”

While some people, like Tricia Mottram, find that Mysimba:

“Seems to be working fine and no side effects.”

Naltrexone and bupropion start working as soon as you take the first dose of Mysimba, and although it can take several weeks before you may notice significant weight loss, users, like Rihab Halloum, share that:

“Mysimba reduces my feelings of hunger, and I’m still in the first week.”

Mysimba success stories like these, along with research data, can help you decide whether this type of weight loss medication is suitable for you. If you’d like to read more success stories or find more real-world opinions about the treatment, please check out our dedicated Mysimba reviews page.

Mysimba

Rated 1.0 out of 5 based on 1 reviews

Rated 1.0 out of 5 based on 1 reviews

• Reduces cravings & emotional eating 
• Convenient, twice-daily oral treatment 
• Proven weight loss results

• Discreet delivery next working day
• Online prescription - No doctor visit

Prices from £109.99 Review More Prices

Start Order More Info

Get Started

Start Order More info

Begin Your Mysimba Journey with Prescription Doctor

If you’re thinking about embarking on a medicated weight loss programme with Mysimba, Prescription Doctor is here to help. For over a decade, we’ve supported countless individuals in achieving their goals, and we’re ready to do the same for you.

Our weight loss service begins with a straightforward online form that covers your medical history and any other treatments you may be taking. Your information is then reviewed by our specialist clinicians to determine whether your chosen medication is suitable for your circumstances. Once approved, your order is dispatched by our General Pharmaceutical Council-registered pharmacy direct to your door.

We offer continuous support throughout your weight loss journey. Our clinicians are available to answer any queries you may have and will regularly check in with you to evaluate progress and ensure your treatment programme is delivering the desired results. In addition, our website contains a wealth of useful information about Mysimba and other available medications.  

Ready to take the first step? Start your Mysimba consultation with Prescription Doctor today.

Authored By

Leanne Edermaniger

Medical Content Writer

Leanne is a science and health content writer focusing on human health and biology while utilising her solid academic background.

Published on: 29/09/2023 Re-Published on: 12/01/2026

Reviewed By

Mohamed Imran Lakhi

MPharm - Lead Pharmacist

Imran Lakhi is the superintendent pharmacist and founder at Prescription Doctor. He has been at the core of our team.

Reviewed on: 12/01/2026