A medical expert has shared his view on the ongoing discussion over whether Mounjaro or Wegovy is the stronger option for weight loss.
In the UK, both medicines are now available for weight management in certain adults, although access depends on eligibility criteria and local prescribing pathways. In the US, tirzepatide is sold for obesity as Zepbound, while Mounjaro remains the diabetes brand name for the same active ingredient.
Wegovy contains semaglutide, which acts on the GLP-1 receptor, while tirzepatide works on both GLP-1 and GIP receptors. That dual action is one reason many clinicians believe tirzepatide can produce greater average weight loss.
That difference has led some to assume Mounjaro may offer better results for weight reduction, and one clinician believes the available evidence points in that direction.
A major head-to-head obesity trial published in 2025 found tirzepatide led to greater weight loss than semaglutide in adults with obesity without diabetes, adding weight to that view. However, results can vary depending on dose, treatment duration, side effects and whether people stay on the medication long term.
Even so, Novo Nordisk, which makes Wegovy, has said “there are no existing head-to-head clinical trials” – so a definitive comparison has not been established.
Meanwhile, Eli Lilly and Company, the manufacturer behind Mounjaro, said:
“We can’t comment on a healthcare professional’s opinion.”
Still, Mr Abdal Alvi, Chief Clinical Officer at Simple Online Pharmacy, argues that Mounjaro is setting the pace for average weight-loss outcomes.
He said:
“Mounjaro currently delivers the greatest average weight loss seen in obesity medication trials, which is why it has generated such significant interest among both patients and healthcare professionals.”
He also stressed that the right treatment depends heavily on the individual and their preferences.
Mr Alvi added:
“Weight-loss treatment is not one-size-fits-all. The best treatment is often the one a patient feels comfortable taking consistently and correctly over the long term.
“For some people, a weekly injection is more convenient. For others, a daily tablet may feel far more manageable. What’s most important is choosing a treatment that fits their lifestyle and can be used safely under appropriate clinical supervision.”
According to him, the current evidence suggests that Mounjaro injections offer the greatest weight-loss effect, followed by Wegovy injections and then the tablet form of Wegovy.
That oral version was approved in the UK by the Medicines and Healthcare products Regulatory Agency on 11 June 2026, making it the country’s first GLP-1 tablet for weight loss and weight management. It may be prescribed to adults with obesity, or adults who are overweight and have at least one weight-related comorbidity, alongside diet and exercise.
With costs beginning at around $5 a day and no need for injections, the tablet is being seen by many as a more practical choice. In practice, though, price, supply, eligibility and clinical suitability can all vary depending on the country, the provider and whether the medicine is being prescribed privately or through a public health system.
Commenting on that decision, Naveed Sattar, Professor of Cardiometabolic Medicine at the School of Cardiovascular & Metabolic Health at the University of Glasgow, said:
“The approval of the once-daily oral form of Wegovy (semaglutide) is welcome news for people living with obesity, particularly those who would prefer not to use injections. “Expanding the range of effective treatments is important in helping people sustainably reduce caloric intakes within an increasingly obesogenic environment.
“With obesity rates in the UK now at very high levels, and associated with substantial multimorbidity, additional treatment options for sustained weight loss are greatly needed.”
Mr Alvi also said the tablet’s approval ‘gives patients and healthcare professionals another evidence-based option’.
He added:
“Expanding the range of effective treatments available is ultimately good news for patients because different treatments suit different people.”
In the US, Wegovy also received a higher-dose 7.2 mg injection approval in March 2026, reflecting ongoing efforts to improve weight-loss outcomes with semaglutide. That means the comparison between the two medicines is no longer just about brand names, but also about formulation, dose and how each treatment is used in real-world care.
For now, the broad picture is that tirzepatide appears to deliver the greatest average weight loss in clinical trials, but Wegovy remains a major option, especially for people who tolerate semaglutide well or prefer a treatment with a long-established obesity indication.
As always, anyone considering a weight-loss medicine should speak to a clinician about their medical history, other medications, side effects and the most appropriate treatment goal.