Mazdutide and tirzepatide (brand name Mounjaro) are both weight-loss medications that work by mimicking natural hormones. Tirzepatide is fully licensed and available in the UK. Mazdutide, on the other hand, was approved in China in 2025 and is still not available in the UK.
While international trials of mazdutide are underway for potential global approval, tirzepatide has been extensively studied worldwide. Here's what we know about how they compare.
What are mazdutide and tirzepatide?
Mazdutide and tirzepatide are both weight-loss injections that work by mimicking natural hormones. Both target two hormones, but they target different combinations.
Tirzepatide is fully approved for use in the UK under the brand name Mounjaro. It's been extensively studied in global trials and is available on prescription.
Mazdutide is only approved for use in China. This means it’s not approved in the UK, or anywhere else in the world, though international trials are underway.
How do they work?
Mazdutide and tirzepatide are both dual-receptor agonists weight-loss injections. This means they act on two different hormone pathways in the body to support weight loss and improve metabolic health.
Both mimic GLP-1, which helps reduce appetite, slow digestion and support blood-sugar control. However, the second hormone pathway differs between the two medications.
Tirzepatide also targets GIP, a hormone that helps regulate blood sugar and reduce appetite.
Mazdutide, instead of GIP, mimics a hormone called glucagon. Glucagon helps your body burn stored fat and use more energy.
Mazdutide vs tirzepatide: Weight loss results
Mazdutide and tirzepatide haven't been compared directly in head-to-head trials, but we can look at data from separate studies.
Clinical trials conducted in China showed people taking 6mg of mazdutide lost an average of 14% of their body weight after 48 weeks. Another Chinese trial found people taking 15mg of tirzepatide (Mounjaro) lost 17.5% of their body weight after 48 weeks.
In global trials, tirzepatide has shown weight loss of around 20.5% at the same dose and timeframe.
Keep in mind: Mazdutide has been studied primarily in Chinese populations, so we don't yet know how results may differ elsewhere. Higher doses of mazdutide (up to 16mg) are being tested which may produce greater weight loss and narrow the gap with Mounjaro.
Side effects and tolerability
Like all medicines, both tirzepatide and mazdutide can cause side effects. Tirzepatide’s safety profile is well established because it has been studied in large, global trials. Mazdutide’s safety data comes mainly from studies in China, where it is approved, and wider international trials are still in progress.
From the data we do have, it seems like most of the side effects of both drugs are similar. This includes feeling sick, being sick, diarrhoea, and constipation.
But trials of mazdutide have also shown that some people experience respiratory tract infections while taking it.
Side effects support at Voy
"If you're using Voy and you experience any side effects, rest assured that our expert clinicians are just a message or phone call away. They can adjust your dose, prescribe medication to ease your symptoms, or simply offer reassurance.
Everyone responds differently to weight loss treatment and we'll help you find what feels right for you."
Dosing and administration
Both tirzepatide and mazdutide are taken as once-weekly injections. Treatment with both medications starts at a lower dose and gradually increases over several weeks to help your body adjust and reduce side effects.
Tirzepatide dosing: Treatment usually starts at 2.5 mg weekly and increases stepwise over several weeks. The highest approved dose is 15mg.
Mazdutide dosing: The doses approved in China are 2mg, 4mg, and 6mg weekly, with 6mg being the highest approved dose. Higher doses of mazdutide (up to 16mg) are currently being tested in ongoing clinical trials, and results from these studies are still to come..
Availability and cost
Tirzepatide is fully approved and available in the UK both on the NHS and privately. However, the NHS has higher eligibility thresholds than private providers.
If you meet NHS eligibility criteria, tirzepatide is available on prescription at the standard NHS prescription charge. Private treatment usually ranges from £150-£350 per month, depending on the dose and provider.
Mazdutide is not available anywhere in the world apart from China. This means it’s not available in the UK, either on the NHS or privately.
If mazdutide does become available in the UK, it will be a prescription medicine. It's likely that it will be prescribed in a similar way to tirzepatide, with costs potentially comparable to other weight loss medications.
Your weight loss journey
Mazdutide might not be available yet, but if you’re wondering whether weight loss medicines like Mounjaro and Wegovy can help you reach your health goals, we can help. Take our quick quiz to get started.
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