Ozempic and Mounjaro

Sep 20, 2025

3 min read

In recent years, the increasing number of patients with obesity and type 2 diabetes has brought forward the need for more effective pharmacological treatments. New-generation drugs in this field stand out with their potential not only to improve glycemic control but also to provide significant weight loss. Semaglutide (Ozempic) and tirzepatide (Mounjaro) are leading representatives of this class and are now considered the beginning of a new era in the treatment of obesity as well as in the management of diabetes.

Semaglutide (Ozempic)

Semaglutide, known commercially as Ozempic, mimics the action of the GLP-1 hormone naturally produced in the human body. By binding to GLP-1 receptors, Ozempic increases insulin secretion from the pancreas, suppresses glucagon release, and thereby lowers blood sugar levels. In addition, by slowing gastric emptying and acting on the appetite center in the brain, it enhances the feeling of satiety and reduces calorie intake.

Tirzepatide (Mounjaro)

Tirzepatide, marketed as Mounjaro, binds not only to GLP-1 receptors, like Ozempic, but also to GIP receptors. Thus, while lowering blood sugar and reducing appetite similar to Ozempic, the activation of GIP receptors further strengthens these effects and also encourages the body to use fat as an energy source.

Research Results on Ozempic (Semaglutide) and Mounjaro (Tirzepatide)

The effects of semaglutide on weight loss have been studied in detail within the broad STEP (Semaglutide Treatment Effect in People with Obesity) clinical trial program. The STEP studies compared overweight or obese individuals (and in some arms, patients with type 2 diabetes) who used Ozempic with those who did not.

STEP 1: In overweight or obese individuals without diabetes, weekly administration of 2.4 mg semaglutide (Ozempic), combined with lifestyle modifications, resulted in an average of 14.9% body weight reduction after 68 weeks, compared with only 2.4% in the placebo group (p<0.001). In addition, 86.4% of patients receiving Ozempic lost 5% or more of their baseline body weight, compared with only 31.5% in the placebo group.
STEP 4: This trial evaluated the effect of discontinuing Ozempic on weight. Initially, all participants received Ozempic for 20 weeks, after which one group continued treatment while the other stopped. At week 68, those continuing treatment lost an additional 7.9%, while those who discontinued experienced a 6.9% weight regain(p<0.001). This shows that the effects of Ozempic may reverse when treatment is stopped.
STEP 5: Conducted to assess long-term effectiveness, this study extended treatment duration to 104 weeks (2 years). At the end of two years, patients receiving Ozempic achieved an average of 15.2% body weight reduction, compared with only 2.6% in the placebo group.

For Mounjaro (tirzepatide), another study compared its effects with both a placebo group and an Ozempic group over a period of 28 weeks. At the end of the study, individuals using Mounjaro achieved an average weight loss of 9.6 kg, while those receiving placebo or Ozempic showed less weight reduction. This stronger effect is attributed to Mounjaro’s dual action on both GLP-1 and GIP receptors.

Risks of Use

These drugs can provide significant and lasting weight loss in some individuals. However, it must be remembered that they were developed for medical conditions such as diabetes. When used randomly and without medical advice, they may cause serious health problems.

Most common side effects: digestive issues such as nausea, diarrhea, or fatigue.
Less common but important risks: pancreatic problems, gallstones, or serious thyroid disorders.
Discontinuation risk: once the drugs are stopped, weight may be regained rapidly.

For this reason, it is essential to consult a doctor before starting these treatments, to assess personal risks, and to plan therapy under medical supervision.

Health is a process; quick solutions can sometimes lead to bigger problems in the long term.

References:

Fornes A, Huff J, Pritchard RI, Godfrey M. Once-Weekly Semaglutide for Weight Management: A Clinical Review. J Pharm Technol. 2022 Aug;38(4):239-246. doi: 10.1177/87551225221092681. Epub 2022 May 13. PMID: 35832567; PMCID: PMC9272494.

Heise T, DeVries JH, Urva S, Li J, Pratt EJ, Thomas MK, Mather KJ, Karanikas CA, Dunn J, Haupt A, Milicevic Z, Coskun T. Tirzepatide Reduces Appetite, Energy Intake, and Fat Mass in People With Type 2 Diabetes. Diabetes Care. 2023 May 1;46(5):998-1004. doi: 10.2337/dc22-1710. PMID: 36857477; PMCID: PMC10154650.