Mazdutide is a new type of weight loss injection. In clinical trials, people taking mazdutide lost up to 14% of their body weight in 48 weeks.
The drug was approved in China in 2025 for weight management and type 2 diabetes. Mazdutide is not yet available in the UK, but larger trials are underway internationally to confirm its safety and effectiveness.
Below, we explore how mazdutide works, how it compares to Wegovy and Mounjaro and potential side effects.
Key Takeaways
- Mazdutide is a weight loss injection targeting GLP-1 and glucagon. It’s approved in China but not yet in the UK
- Clinical trials show 11-14% weight loss at 48 weeks, plus improvements in blood sugar, cholesterol and blood pressure
- In a Chinese trial in people with type 2 diabetes, mazdutide beat semaglutide for both weight loss and blood sugar control.
- Side effects are mainly mild digestive issues (nausea, vomiting, diarrhoea)
- UK approval could be from 2026–2027 if ongoing trials are successful.
What is mazdutide?
Mazdutide is a once-a-week injection that supports weight loss and helps control type 2 diabetes.
The drug is already approved in China as Xinermei (manufactured by Innovent Biologics). Outside China, it is being co-developed with Eli Lilly, which is running larger global trials to confirm how well it works in different populations.
Unlike medications like Wegovy (semaglutide), mazdutide is a dual-agonist peptide, meaning it activates two hormones: GLP-1 (for appetite and blood sugar control) and glucagon (for fat burning and energy use). This dual action is designed to produce greater weight loss than GLP-1-only treatments.
Beyond weight loss and diabetes, mazdutide is also being studied for fatty liver disease (MAFLD), obstructive sleep apnoea, alcohol use disorder, heart failure and teenage obesity.
How does mazdutide work?
Mazdutide works in a similar way to Wegovy or Mounjaro but targets a different combination of hormones.
Mazdutide mimics two natural gut hormones:
- GLP-1, which helps reduce appetite, slows digestion and supports healthy blood sugar levels.
- Glucagon, which helps the body burn stored fat and use more energy.
Together, mazdutide lowers appetite, reduces calorie intake, and boosts fat burning, which leads to weight loss and better metabolic health overall.
Mazdutide results from clinical trials
Clinical trial data shows mazdutide delivers substantial weight loss results and metabolic improvements.
Weight loss: In 610 adults with obesity, participants lost 11% of their body weight on the 4mg dose and 14% on a 6mg dose over 48 weeks.
Metabolic improvements: Beyond weight loss, mazdutide reduced waist circumference, blood sugar levels, cholesterol and blood pressure.
Liver health: In patients with fatty liver disease, the 10mg dose reduced liver fat by 68% after 32 weeks and 70% achieved normal liver fat levels after 48 weeks.
Overall, these results show that mazdutide supports multiple areas of metabolic health, not just weight loss.
Mazdutide dosing and administration
Mazdutide is given as a once-weekly subcutaneous injection (under the skin), similar to other weight loss injections like Wegovy and Mounjaro.
Approved doses in China
The doses approved in China are 2mg, 4mg and 6mg weekly. Treatment starts at a lower dose and gradually increases over several weeks to help your body adjust and reduce side effects.
Higher doses in development
Clinical trials have tested higher doses of mazdutide, with studies showing safety and effectiveness up to 16mg weekly.
Future approvals outside China may include different dosing options.
Mazdutide side effects and safety
Most people in trials experienced mild to moderate side effects, similar to other GLP-1 medications, such as Wegovy side effects.
The most common side effects have been digestive symptoms such as:
- Nausea
- Vomiting
- Diarrhoea
- Abdominal bloating or discomfort
Some people also reported upper respiratory tract infections (cold-like symptoms), but these occurred in both the mazdutide and placebo groups in trials.
Overall, mazdutide appears safe based on current trial data, with side effects typically mild and manageable through dose adjustment.
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."
Who shouldn't take mazdutide?
Mazdutide isn't right for everyone. Based on trial exclusion criteria and what we know about licensed GLP-1 medications, you shouldn't take it if you have:
- A personal or family history of medullary thyroid cancer or multiple endocrine neoplasia type 2 (MEN 2)
- A history of pancreatitis
- Significant or active gallbladder disease
- Pregnancy or plans to become pregnant in the near future
Mazdutide isn’t yet available in the UK. Final prescribing guidelines will be determined upon approval. Always discuss your full medical history with a clinician before starting any weight loss medication.
Is mazdutide better than Wegovy?
In a head-to-head trial in adults with type 2 diabetes and obesity, mazdutide outperformed semaglutide (the active ingredient in Wegovy) for both weight loss and blood sugar control. At 32 weeks, 48% of people on mazdutide achieved healthy blood sugar levels (HbA1c below 7%) and at least 10% weight loss, compared with 21% on semaglutide.
However, this evidence comes from a single study in Chinese patients with diabetes. More global trials are needed to see if the same advantage holds in other populations, including people without diabetes.
Is mazdutide better than Mounjaro?
Both mazdutide and Mounjaro (tirzepatide) are dual-agonist weight loss medications that mimic two hormones, but they target different combinations. Mounjaro activates GLP-1 and GIP, while mazdutide activates GLP-1 and glucagon.
In separate trials, users taking Mounjaro 15mg lost around 20% at 48 weeks (estimated from 72-week data), while those taking mazdutide 6mg achieved 14% weight loss at 48 weeks. But these results come from different studies with different patient populations, and no head-to-head trials have been conducted yet, making direct comparison difficult.
It's also worth noting that mazdutide is being studied at higher doses (up to 16mg), which are likely to produce better results than the 6mg dose and may narrow the gap with Mounjaro.
Is mazdutide better than retatrutide?
Retatrutide is a weight loss drug that’s still in development. It activates GLP-1, GIP and glucagon, showing the greatest average weight loss in trials to date. Mazdutide shares two of these targets (GLP-1 and glucagon) but doesn't activate GIP.
While mazdutide's results are strong, early data suggest retatrutide may achieve higher overall weight loss results due to its “triple-G” action.
Neither medication is licensed in the UK yet, and direct comparative trials would be needed to determine which is more effective.
Can you get mazdutide in the UK?
No, mazdutide is not yet available in the UK. It was approved in China in 2025, but further trials and UK regulatory approval are needed before it can be prescribed here.
If trials are successful, mazdutide could potentially be approved by 2026 or 2027. In the meantime, several licensed weight loss medications are already available, including Wegovy, Mounjaro, and Orlistat weight loss pills.
If you're wondering which weight loss medication might be right for you, take our eligibility quiz now.
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