How Weight Loss Medications Work: Mounjaro and Wegovy
You’ve probably heard about the medications Mounjaro and Wegovy, right? They have been gaining prominence in the medical world, especially for those dealing with type 2 diabetes and obesity. For many, these drugs represent a revolution in weight loss treatment!
But have you ever wondered how they actually work? In this article, we explain how these medications function and why they are considered a major breakthrough in weight loss science.
The Role of Obesity in Global Health
Obesity is a global public health issue linked to an increasing prevalence of multiple chronic diseases, such as diabetes, hypertension, and cardiovascular diseases.
Obesity treatment involves lifestyle changes, but many patients regain lost weight due to physiological changes that affect metabolism and increase appetite.
In this context, medications play a crucial role by helping to regulate appetite, enabling more effective and sustainable weight loss.
Currently, medical guidelines recommend pharmacotherapy combined with lifestyle modifications for obesity treatment.
How Do Wegovy and Mounjaro Work in the Body?
The two most advanced medications on the market are:
- Semaglutide (marketed as Wegovy)
- Tirzepatide (marketed as Mounjaro)
Both are administered via weekly injections, applied subcutaneously in the abdomen, thigh, or arm.
1. Mechanism of Action
These medications mimic a hormone called GLP-1 (glucagon-like peptide-1), which is produced by the intestine after meals. This hormone signals the brain that we are full, reducing appetite.
In the case of Tirzepatide (Mounjaro), there is an additional effect: besides acting on GLP-1 receptors, it also activates GIP (glucose-dependent insulinotropic peptide) receptors.
GIP is another hormone that plays a crucial role in regulating blood glucose levels and appetite control, further enhancing the feeling of fullness and promoting greater weight loss.
How Much Weight Can I Lose Using These Medications?
Semaglutide (Wegovy)
Studies indicate that, when combined with diet and physical activity, Semaglutide can lead to weight loss of over 10% of body weight within one year. Effects begin to be noticeable within the first few weeks.
Tirzepatide (Mounjaro)
Tirzepatide is a newer medication, and studies show that its effects may be even more powerful. Patients experienced up to 20% weight reduction with continued use.
Side Effects
Like any medication, Wegovy and Mounjaro can cause side effects.
Semaglutide (Wegovy)
The main side effects include:
- Nausea (44%)
- Diarrhea (30%)
- Vomiting (24%)
- Constipation (24%)
- Abdominal pain (20%)
These symptoms are usually mild to moderate and occur mainly at the beginning of treatment.
Constipation can last up to 45 days, while nausea and vomiting generally disappear within a week.
Tirzepatide (Mounjaro)
The side effects of Tirzepatide are similar but tend to occur less frequently:
- Nausea (25%-29%)
- Diarrhea (19%-23%)
- Constipation (11%-17%)
- Vomiting (8%-13%)
These effects usually occur during dose increases.
If I Stop Taking the Medication, Will I Regain Weight?
The answer depends on the patient’s lifestyle.
- If a long-term lifestyle change is maintained, it is possible to keep the weight off.
- If old habits return, there is a high chance of regaining the lost weight.
Additionally, these medications are approved for long-term use and may be necessary as a continuous treatment for patients with chronic obesity.
Studies show that one year after stopping Semaglutide, participants regained two-thirds of their lost weight. This reinforces that obesity is a chronic disease, and its approach needs to be long-term.
Conclusion
The medications Wegovy and Mounjaro represent significant advancements in obesity treatment.
They work directly by regulating appetite and metabolism, allowing for more effective and sustainable weight loss.
However, to maintain results, it is essential to combine treatment with lifestyle changes, including a balanced diet and regular physical activity.
Always consult a doctor or specialist before starting any weight loss treatment!
References
- Schmitz SH, Aronne LJ. The Effective Use of Anti-obesity Medications. Gastroenterol Clin North Am. 2023 Dec;52(4):661-680. doi: 10.1016/j.gtc.2023.08.003.
- Wilding JPH, Batterham RL, Davies M, Van Gaal LF, et al. Weight regain and cardiometabolic effects after withdrawal of semaglutide: The STEP 1 trial extension. Diabetes Obes Metab. 2022 Aug;24(8):1553-1564. doi: 10.1111/dom.14725.