Wegovy, Mounjaro, Semaglutide and Tirzepatide: what’s the difference?

Molecule first, Brand second

Medicine conversations can become confusing because people often use a brand name as if it were the drug itself. Semaglutide is an active molecule. Depending on country and indication, it is marketed under brands including Wegovy and Ozempic. Tirzepatide is the active molecule marketed internationally under brands including Mounjaro and Zepbound.

A brand name does not tell you the whole clinical story. The indication, dose and regulatory approval matter.

Semaglutide: the medicine behind Wegovy

Semaglutide is a GLP-1 receptor agonist with an extensive clinical-trial program in obesity. Wegovy contains semaglutide and has been studied specifically for chronic weight management, including the large STEP clinical-trial program.

In STEP 1, adults with overweight or obesity without diabetes who received semaglutide 2.4 mg alongside lifestyle intervention lost an average of about 14.9% of body weight over 68 weeks, compared with about 2.4% with placebo. The STEP program also gives clinicians detailed evidence on dosing, efficacy and the adverse-effect profile of semaglutide in weight management.

What about Mounjaro?

Mounjaro contains tirzepatide, a different medicine that activates both GIP and GLP-1 receptors. It is another evidence-based treatment option and has shown substantial average weight reduction in clinical trials.

Medara may offer both semaglutide and tirzepatide where clinically appropriate, but the choice should always be individualised. A larger average result in one trial does not automatically make one medicine the best option for every patient.

Why Wegovy rather than Ozempic for weight loss?

Wegovy and Ozempic both contain semaglutide, but they were developed and studied for different primary treatment purposes. Wegovy has a dedicated chronic weight-management indication in India and a weight-management dose-escalation schedule up to 2.4 mg weekly, supported by the STEP obesity trial program.

That alignment between the approved use, the studied dose and the obesity-specific clinical evidence is why Wegovy can be the preferred semaglutide product when the treatment goal is chronic weight management, subject to the treating physician's assessment.

The useful question is 'which treatment fits me?'

The most clinically useful question is which treatment has evidence that matches your health needs and can be used safely and consistently. Wegovy may be Medara's primary medication, while Mounjaro remains an alternative where the independent treating physician considers it more appropriate.

Side effects, contraindications, medication availability, cost, treatment goals and long-term follow-up all matter.

Resources

• Wilding JPH, et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. New England Journal of Medicine. 2021. PubMed

• Aronne LJ, et al. Tirzepatide as Compared with Semaglutide for the Treatment of Obesity. New England Journal of Medicine. 2025. PubMed

• Endocrine Society of India. Clinical Practice Guidelines for the Evaluation and Management of Obesity in India: 2025 Update.

Written and clinically reviewed by: Dr Saran Seker, MBBS (Aus), Chief Medical Officer

Last reviewed: September 2026