Should I switch from mounjaro to wegovy?
Deciding on the right medication for your weight management journey can be complex, especially with new, highly effective treatments becoming available. Two of the most discussed medications are Mounjaro (tirzepatide) and Wegovy (semaglutide). At Hopwoods Pharmacy in Cardiff, we understand you may have questions about these weight loss injections and whether switching between them is right for you. We have put together this post to help educate our patients on the comparisons between these two effective weight loss treatments.
Understanding GLP-1 Agonists
Both Mounjaro and Wegovy belong to a class of medications called GLP-1 agonists (glucagon-like-peptide-1). GLP-1 is a hormone released from the gut which helps to regulate our appetite. The injections
mimic these hormones and have powerful effects on our appetite - making you feel fuller for longer. They also help to regulate blood sugar and slow down how quickly food moves through your stomach. Simply put, they reduce your appetite helping you to eat less which enters you into a calorie deficit and the energy your body requires which no longer comes through your diet your body will utilise your reserves and fat stores for energy - resulting in weight loss.
Mounjaro vs Wegovy: a direct comparison
While both are administered as a once-weekly injection, their active ingredients and mechanisms of action have key differences:
| Feature | Mounjaro | | Wegovy |
| | | |
| Active Ingredient | Tirzepatide | | Semaglutide |
| Mechanism of Action | GLP-1 and GIP Agonist | | GLP-1 Agonist |
| Average Weight Loss | 22% | | 16% |
| Cardiovascular Benefit | Under investigation | | Proven in multiple clinical trials |
| Clinical Experience | Newer agent | | Longer use in practice |
Mounjaro, being a newer agent, is a unique GLP1-GIP Agonist, whereas Wegovy is a dedicated GLP-1 Agonist.
The key difference often discussed is the average weight loss observed in trials; 22% mounjaro compared to 16% wegovy. However, wegovy has greater evidence for cardiovascular benefit beyond the effects of weight loss and it is still a very effective option for those looking to lose weight. It is important to note that there are currently no direct randomised controlled trials that compare the total weight loss of Mounjaro and Wegovy patients head-to-head.
However, we can form assumptions about their effectiveness by reviewing data from the drugs' individual trials, SURMOUNT-1 and STEP-5
Switching Medications
If you are considering switching from a medium or high dose of one drug to the other, be aware that there is no direct guidance on the safety of this action. The ''safest'' way to perform this switch is to have a
one-week washout where no medication is taken and then begin the newest medication at it's lowest dosage. However, there is real-world data and clinical experiece where prescribers have safely switched patients to the ''equivalent dose'' of the new medication. This decision should be made in collaboration with your prescriber. Our trained pharmacist here at Hopwoods Pharmacy can talk you through the instructions and implications of this in more details.
Expert advice at your trusted pharmacy in Cardiff
Any decision to switch between these powerful weight loss injections must be made in consultation with a qualified healthcare professional. As your local
pharmacy in Cardiff, the team at
Hopwoods Pharmacy is here to provide personalised advice based on your medical history and treatment goals. We can discuss the clinical data, potential benefits, and the safest switching protocol to ensure your
weight management journey is both effective and secure. Get in touch with us today for a
confidential discussion.
