Is it true that most people who stop using weight-loss drugs return to their original weight shortly after they quit? Mounjaro (tirzepatide), a substance that works on two body signals (GLP-1 and GIP receptor agonists) and received approval for type 2 diabetes and helping manage weight, causes a large amount of weight reduction while people take it - often 15–20% of the body's mass in controlled medical settings. For those interested in a more detailed breakdown, we've published a comprehensive guide to Mounjaro. However, it's crucial to know that the majority of users get back a substantial amount, generally more than 75–80% of the weight they shed, within one year after they stop taking the drug.

Weight Loss During Treatment: What Clinical Data Shows

In the SURMOUNT-4 study, people who had extra body fat achieved important body weight reduction over 36 weeks while they received tirzepatide treatment. They also saw better results for heart health signs, such as the size around the waist, blood pressure, cholesterol levels, HbA1c, as well as insulin levels when fasting.

A study using a mouse model, presented at ENDO 2025, showed outcomes similar to those found in people. Tirzepatide reduced body mass and fat mass by about 20% after 16 weeks. This reduction happened mainly because of the loss of fat tissue.

Do Digital Tools Improve Results?

Information from the everyday world, gathered from a study in 2025 that looked back at people who use GLP-1 drugs, including those on tirzepatide, showed a better path toward weight loss compared to semaglutide. This was especially true among participants who regularly used digital support. They reached higher rates of ≥5%, ≥10%, in addition to ≥15% body mass reduction by months 3–5.

A large review of 37 studies up to February 2025 (covering 9,341 participants) confirmed that these drugs produce "very good" initial body mass losses after about 39 weeks of treatment.

These outcomes match clinical tests that show how well tirzepatide works to cause large body mass reduction in people with and without diabetes. The exact average amount of weight reduction does differ based on the dosage, the time period of use, and the specific group of people.

The Reality of Weight Regain: Post-Treatment Trends

Keeping the weight off proves difficult when people do not continue the drug use. In a closer look at the data from SURMOUNT-4, 82% of the participants got back at least 25% of the weight they lost within one year (week 36 to 88) after they stopped taking tirzepatide. In fact, 82.5% met this level.

What Happens to Health Markers After Stopping Mounjaro?

Getting back more weight went along with worse results in heart health signs. Those who got back ≥75% of the weight saw their waist size increase by 14.7 cm, their top blood pressure number rise by 10.4 mmHg, non-HDL cholesterol increase by 10.8%, HbA1c increase by 0.35%, and insulin levels when fasting became much worse.

A January 2026 analysis in the BMJ predicted that body mass and signs of diabetes and heart disease risk return to levels seen before treatment in under two years after stopping the drug. The average weight regained was 0.4 kg each month - nearly four times faster than after diet and exercise alone.

It is important to note that only eight studies in this review looked at newer GLP-1 drugs like tirzepatide, and none followed people for more than 12 months, which shows there are gaps in the available data.

2025 Trends: Enhanced Outcomes with Support

Using digital tools made the outcomes better in 2025 studies. Participants who used tirzepatide along with a digital program for managing body mass had a much greater likelihood of reaching a medically important weight reduction (for example, ≥5–15%). They did better than people who did not use the digital tools or those who used semaglutide.

This suggests that using medicine together with tools for changing behavior improves success in the short term, though long-term data remains limited.

Newer research also connects the body mass reduction from tirzepatide to other good effects. One example is slowed growth of breast cancer related to extra body fat in mice, which links to the reduction of fat.

Safety reviews from FDA information point out issues with the stomach and intestines but confirm the drug works. They urge carefulness about how the drug gets promoted in the real world.

Key Takeaways from 2025 Data

You should expect an initial loss of 15–20% of your body mass while you adhere to Mounjaro, but you must plan for a high chance of getting the weight back without continuous treatment or support.

Studies emphasize that tirzepatide holds an advantage over other options like semaglutide. To see how it compares to other weight-loss solutions, it's helpful to look at the broader landscape. They also highlight the need to bring lifestyle changes into your routine to keep the benefits. Studies that go on now will make the long-term effects clearer after 2025. Please talk to medical professionals for an assessment tailored to you, because results vary from person to person.

FAQ

Must I take Mounjaro forever to keep the weight off?

Based on the available clinical data, maintaining the weight loss achieved with Mounjaro (tirzepatide) proves highly difficult after you stop the medication. Studies show that a large majority of users (over 80%) regain a significant portion of the lost weight within one year of stopping treatment. To keep the weight off long-term, you should anticipate needing continuous treatment or a very strong combination of behavioral and lifestyle changes. If you're considering this path, you can explore options for a weekly weight loss injection.

Is Mounjaro better than semaglutide for weight loss?

Current real-world and clinical data suggest tirzepatide (Mounjaro) produces superior body mass reduction results compared to semaglutide. Studies in 2025 showed that people on tirzepatide, especially those using digital support tools, reached higher rates of clinically significant weight loss (e.g., losing 5%, 10%, or 15% of their body mass) in the short term.

How quickly do health markers worsen after I stop the drug?

When you stop taking tirzepatide, health markers such as blood pressure, waist circumference, next to blood sugar levels tend to worsen quickly, often returning toward pre-treatment levels. Data shows that the rate of weight regain (about 0.4 kg each month) makes the reversal of cardiometabolic benefits likely within one to two years if you do not continue with the drug.