GLP-1 weight loss medications have transformed the treatment of obesity in recent years, helping many people achieve significant and sustained weight loss.
But with several options now available, a common question remains: which one works best?
Study Finds Tirzepatide Leads to Greater Weight Loss
A new systematic review and network meta analysis published in Wiley Online Library suggests that tirzepatide based medications, including Zepbound and Mounjaro, may offer greater weight loss benefits than semaglutide based treatments such as Wegovy and Ozempic.
Researchers analysed data from 15 Phase 3 clinical trials involving more than 14,059 adults with obesity who did not have type 2 diabetes. The study compared three approved weight loss medications: tirzepatide, semaglutide and liraglutide.
According to the study authors, "Tirzepatide, particularly at higher doses, provides the greatest weight reduction in adults without diabetes."
Participants taking tirzepatide lost approximately 15-20% of their body weight on average. In comparison, people using semaglutide lost around 12-13%, while liraglutide users experienced average weight loss of about 5%.
Why Does Tirzepatide Work Better?
Experts believe tirzepatide's stronger results may be linked to its dual action mechanism. While semaglutide and liraglutide target GLP-1 receptors, tirzepatide activates both GLP-1 and GIP receptors. These hormones help regulate appetite, slow digestion, improve blood sugar control and increase feelings of fullness after meals.
By targeting two pathways instead of one, tirzepatide may provide a greater effect on appetite regulation and energy balance, leading to more substantial weight loss.
Does That Mean Wegovy Is No Longer a Good Option?
Not necessarily.
Although tirzepatide appears to produce greater average weight loss, Dr. Clare Thompson stress that there is no single medication that is right for everyone.
Dr Clare Thompson, a GP and weight management specialist, noted that semaglutide has been available for longer and has a stronger body of long term evidence supporting its cardiovascular benefits. Studies have shown that semaglutide can help reduce the risk of heart attacks, strokes and certain kidney related complications in eligible patients.
Semaglutide is also available in tablet form, offering an alternative for people who prefer not to use injections.
Side Effects Still Need Consideration
The analysis found that both tirzepatide and semaglutide were associated with a higher risk of side effects compared with placebo. Commonly reported issues included nausea, vomiting, diarrhoea and other gastrointestinal symptoms.
Researchers emphasised that future studies should explore long term outcomes, including weight regain after stopping treatment, cost effectiveness and patient preferences.
Weight Loss Medication Works Best Alongside Lifestyle Changes
While GLP-1 medications can be highly effective, experts agree that they should not be viewed as a standalone solution.
A balanced diet, regular physical activity, adequate protein intake and strength training remain essential for preserving muscle mass and supporting long term health during weight loss.
Obesity is increasingly recognised as a chronic medical condition that requires an individualised approach. For some people, tirzepatide may offer the greatest weight loss results. For others, semaglutide may be the more appropriate choice based on their medical needs and personal circumstances.