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Why You Might Not Be Losing Weight On Mounjaro And What To Do About It

Why You Might Not Be Losing Weight On Mounjaro And What To Do About It


Written by:

MedExpress

Medically reviewed by:

Dr Zoë Lees

Published:

13 February 2026

Reading time: 4 minutes
Why You Might Not Be Losing Weight on Mounjaro and What to Do About It

Mounjaro has been shown to result in a weight loss of up to 22.5% body weight on average. [1] But the journey to weight loss isn’t always linear, and you might come to a point where it slows down or seems to pause completely. There are a number of reasons why this might happen, and our clinical experts are here to help.

Article Summary:

  • Mounjaro (tirzepatide) is a prescription treatment for weight loss and type 2 diabetes. It works by controlling blood sugar and reducing appetite.
  • This dual action GIP/GLP-1 receptor agonist could help you lose an average of 22.5% of your body weight in 72 weeks.
  • If weight loss slows down or stops completely, you may want to try increasing your water intake, increasing your exercise intensity or contacting MedExpress to discuss your dose options.

What Is Mounjaro?

Mounjaro is a prescription weight loss medication which contains the active ingredient tirzepatide. A safe and well-researched treatment, it works by mimicking the glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) hormones that your gut naturally produces after eating. This supports weight loss by reducing hunger and cravings, improving blood sugar control and slowing down how quickly food leaves the stomach, which helps you feel fuller for longer. [2]

How Much Weight Will You Lose On Mounjaro?

Each of our bodies and lifestyles is unique, so your clinician will never give you an exact figure when it comes to predicted weight loss. However, people in clinical trials using Mounjaro alongside diet and lifestyle changes lost an average of 22.5% of their body weight after 72 weeks. [1]

Why Have I Stopped Losing Weight On Mounjaro?

It is normal for weight loss to slow down when taking any treatment, such as Mounjaro. This may be your body adapting to the medication, rather than it not working. There are several reasons why your weight loss might have stopped completely, which you can overcome with some small adjustments.

  • Adjusting to your medication means you might not experience side effects as strongly, and have more of an appetite. This may make it harder to keep eating in a calorie deficit.
  • Your dose may be too low. Doses can be increased by 2.5mg every four weeks, so it can take up to five months to reach the maximum 15 mg dose. [3]
  • If you’ve missed doses or don’t inject on the same day or in the recommended sites each week, it can affect how well the medication works.
  • Everyday lifestyle changes like not sleeping well, moving less, or feeling stressed can affect your progress.

How To Get Back On Track With Your Weight Loss Goals

  • Keep a food diary for a few weeks to better understand how many calories you’re eating. You can then adjust your intake if needed.
  • Up your water intake, especially before meals, to help you feel fuller.
  • Exercise regularly, prioritising muscle-building movement to further support metabolism. You’ll find our guide to movement here.
  • Stay consistent with when you inject your Mounjaro each week. Set reminders so that you never miss a dose.
  • Have a check-in with your MedExpress clinical team. They will advise if you’re on the right dose or if any adjustments need to be made.
  • Try to be patient. In clinical trials, people taking Mounjaro for over a year continued to see benefits. Weight loss is a long-term goal with no quick fixes. Remember, it’s normal to have ups and downs along the way.

If you want to learn more about Mounjaro, you’ll find our complete guide here. Or if you’re interested in starting your weight loss journey, you can discover which treatment is suitable for you with MedExpress.

References

  1. Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, et al. Tirzepatide Once Weekly for the Treatment of Obesity. New England Journal of Medicine [Internet]. 2022 Jun 4;387(3):205–16. Available from: https://www.nejm.org/doi/full/10.1056/NEJMoa2206038
  2. Mounjaro: Uses, Dosage, Side Effects & Warnings [Internet]. Drugs.com. Available from: https://www.drugs.com/mounjaro.html
  3. Mounjaro KwikPen 2.5mg solution for injection in pre-filled pen - Summary of Product Characteristics (SmPC) - (emc) [Internet]. www.medicines.org.uk. Available from: https://www.medicines.org.uk/emc/product/15481/smpc#gref

Next scheduled review date: 13 February 2029

Authors

MedExpress Logo

Written by: MedExpress

MedExpress

Dr Zoë Lees

Medically reviewed by: Dr Zoë Lees

Dr Zoe Lees is a medical writer with postdoctoral research experience from the University of Glasgow, where she focused on metabolic complications of pregnancy and the role of adipose tissue (fat tissue) function. Zoe has a specialist interest in medical communications and is dedicated to delivering content of the highest scientific quality, grounded in robust evidence-based research.

Note from the experts

Remember: This blog shouldn’t be regarded as medical advice, diagnosis, or treatment. We make sure everything we publish is fact checked by clinical experts and regularly reviewed, but it may not always reflect the most recent health guidelines. Always speak to your doctor about any health concerns you have.